Rozprawy doktorskie na temat „ERPs”

Lo studio si prefigge di indagare il decoding simultaneo degli elementi vocali e della mimica facciale delle emozioni mediante i potenziali evocati corticali (ERPs), utilizzando un'ampia gamma di emozioni. Stimoli emotivi vocali e patterns mimici sono stati accoppiati in condizioni di congruenza o di incongruenza. Le variazioni ERPs e i tempi di risposta (TR) rilevati sono state sottoposti ad analisi univariata della varianza per misure ripetute (ANOVA). Alcuni fenomeni ERP sono altamente sensibili alla condizione di congruenza/incongruenza del pattern (con una maggiore ampiezza per stimoli congruenti rispetto a stimoli incongruenti) e costituiscono marker specifici dell'integrazione intersensoriale. In particolare, i dati permettono di riconoscere l'indice di media latenza P200 come un marker dell'integrazione intersensoriale di stimoli emotivi. Altri fenomeni, invece, maggiormente sensibili al contenuto emotivo, segnalano la presenza di processi cognitivi legati più in generale al decoding emotivo. I risultati indicano inoltre che l'integrazione, che nelle prime fasi di processamento è un fenomeno automatico, coinvolge successivamente processi decisionali intenzionali. Infine, è stato riscontrato che la condizione di congruenza provoca un effetto di riduzione dei TR per alcune delle emozioni analizzate (tristezza) ed un effetto inverso per un secondo gruppo di emozioni (paura, rabbia e sorpresa). Tale risultato viene discusso in riferimento al significato adattivo dei diversi correlati emotivi e dei rispettivi processi di decodifica cross-modale.<br>The study investigates the simultaneous processing of emotional tone of voice and emotional facial expression by event-related potentials (ERPs), through an ample range of different emotions. Auditory emotional stimuli and visual patterns were matched in congruous and incongruous pairs. ERPs variations and behavioral data (response time) were submitted to repeated measures analysis of variance (ANOVA). ANOVA showed numerous ERP effects, with different cognitive functions. Some of them, in particular the medium-latency P200, are highly sensible to pattern congruent/incongruent condition (with more intense amplitude for congruent rather then incongruent stimuli) and constitute intersensory integration specific markers. The other ERP effects, instead, are more sensible to the emotional content and signal the presence of cognitive processes that are more generally tied to the emotional decoding. Furthermore results show that, in the first processing phase, integration is an automatic and obliged phenomenon, while later it implies intentional decisional processes. Finally, a TR reduction was found for some congruous patterns (i.e. sadness) and an inverted effect for a second group of emotions (i.e. fear, anger, and surprise). Finally, behavioural results indicate that congruence causes a RT reduction for some emotions (sadness) and, on the contrary, an inverse effect for other emotions (fear, anger, surprise). This result is discussed with reference to different emotional correlates adaptive function and their respective cross-modal decoding processes.

Lo studio si prefigge di indagare il decoding simultaneo degli elementi vocali e della mimica facciale delle emozioni mediante i potenziali evocati corticali (ERPs), utilizzando un'ampia gamma di emozioni. Stimoli emotivi vocali e patterns mimici sono stati accoppiati in condizioni di congruenza o di incongruenza. Le variazioni ERPs e i tempi di risposta (TR) rilevati sono state sottoposti ad analisi univariata della varianza per misure ripetute (ANOVA). Alcuni fenomeni ERP sono altamente sensibili alla condizione di congruenza/incongruenza del pattern (con una maggiore ampiezza per stimoli congruenti rispetto a stimoli incongruenti) e costituiscono marker specifici dell'integrazione intersensoriale. In particolare, i dati permettono di riconoscere l'indice di media latenza P200 come un marker dell'integrazione intersensoriale di stimoli emotivi. Altri fenomeni, invece, maggiormente sensibili al contenuto emotivo, segnalano la presenza di processi cognitivi legati più in generale al decoding emotivo. I risultati indicano inoltre che l'integrazione, che nelle prime fasi di processamento è un fenomeno automatico, coinvolge successivamente processi decisionali intenzionali. Infine, è stato riscontrato che la condizione di congruenza provoca un effetto di riduzione dei TR per alcune delle emozioni analizzate (tristezza) ed un effetto inverso per un secondo gruppo di emozioni (paura, rabbia e sorpresa). Tale risultato viene discusso in riferimento al significato adattivo dei diversi correlati emotivi e dei rispettivi processi di decodifica cross-modale.<br>The study investigates the simultaneous processing of emotional tone of voice and emotional facial expression by event-related potentials (ERPs), through an ample range of different emotions. Auditory emotional stimuli and visual patterns were matched in congruous and incongruous pairs. ERPs variations and behavioral data (response time) were submitted to repeated measures analysis of variance (ANOVA). ANOVA showed numerous ERP effects, with different cognitive functions. Some of them, in particular the medium-latency P200, are highly sensible to pattern congruent/incongruent condition (with more intense amplitude for congruent rather then incongruent stimuli) and constitute intersensory integration specific markers. The other ERP effects, instead, are more sensible to the emotional content and signal the presence of cognitive processes that are more generally tied to the emotional decoding. Furthermore results show that, in the first processing phase, integration is an automatic and obliged phenomenon, while later it implies intentional decisional processes. Finally, a TR reduction was found for some congruous patterns (i.e. sadness) and an inverted effect for a second group of emotions (i.e. fear, anger, and surprise). Finally, behavioural results indicate that congruence causes a RT reduction for some emotions (sadness) and, on the contrary, an inverse effect for other emotions (fear, anger, surprise). This result is discussed with reference to different emotional correlates adaptive function and their respective cross-modal decoding processes.

Le sommeil est défini comme un état comportemental de repos où nous perdons conscience de notre environnement et notre réactivité aux stimuli extérieurs est drastiquement réduite. Pourtant, lorsque nous dormons, l’appel par notre prénom ou à la sonnerie du réveil peuvent encore nous réveiller, suggérant qu’un certain degré de traitement des stimuli reste possible. Dans ce travail, nous soulevons la question de la profondeur du traitement de l’information extérieure pendant le sommeil. Nous avons enregistré simultanément l’activité cérébrale de sujets sains adultes en électro- et magnéto-encéphalographie (EEG et MEG) en réponse à des stimulations auditives, avant, pendant, et après une courte période de sommeil. Afin de tester la profondeur du traitement de l’information à travers la hiérarchie corticale, nous nous sommes concentrés sur les capacités de codage prédictif hiérarchique, qui permettent au cerveau d’anticiper les évènements futurs à partir d’une connaissance passée. Les prédictions sont faites à de nombreuses si ce n’est toutes les étapes de la hiérarchie corticale. Tester les différents niveaux de prédiction nous permet donc d’évaluer précisément à quel niveau l’intégration de l’information est interrompue. Nous avons d’abord testé les capacités du cerveau à détecter la nouveauté auditive. Nous avons présenté aux sujets des séquences de sons comprenant des régularités temporelles à courte (locale) ou à longue (globale) échelle de temps, et analysé les réponses cérébrales à des sons violant ces régularités. Les réponses cérébrales à ces violations locales ou globales se traduisent respectivement en EEG à l’éveil par l’émergence de deux signaux d’erreur de prédiction : la négativité de mismatch (MMN) et la P300. Notre analyse révèle que la MMN et la P300 disparaissent toutes deux dans le sommeil avec la perte des activations des aires associatives préfrontales et pariétales. Au cours de l’endormissement, la MMN diminue progressivement, tandis que la P300 disparait brutalement avec la perte de conscience des stimuli. Ce comportement tout-ou-rien renforce l’hypothèse que la P300 est un marqueur de la conscience. Malgré tout, nous avons montré que le cerveau détecte toujours les nouveaux sons et peut s’y habituer, mais seulement dans un contexte limité d’adaptation sensorielle de bas niveau. Après avoir démontré la perte des capacités de codage prédictif dans le sommeil dans le cadre de régularités statistiques arbitraires et nouvellement acquises, dans une deuxième série d’expériences nous avons testé la capacité du cerveau endormi à établir des prédictions sur les sons à venir dans le cadre de connaissances sémantiques connues déjà stockées en mémoire à long terme. Nous avons présenté à des sujets endormis des opérations arithmétiques simples, comme “deux plus deux égal neuf”, et nous avons enregistré les réponses cérébrales aux résultats corrects et aux résultats faux. Nous avons découvert que le cerveau était toujours capable de détecter les violations arithmétiques dans le sommeil, avec des activations en partie similaires à celles de l’éveil. Nous suggérons que, bien que le sommeil prévienne tout calcul explicite, il y a conservation des signaux d’erreur de prédiction pour les opérations arithmétiques simple déjà mémorisées. Ce travail clarifie à quel niveau l’intégration de l’information auditive est interrompue pendant le sommeil, et quelles fonctions cognitives persistent ou s’altèrent. La persistance de l’adaptation sensorielle et des capacités de prédiction à partir de connaissances déjà mémorisées sont probablement responsables de la réactivité résiduelle qui peut être observée pendant le sommeil alors que les sujets sont inconscients. Finalement, ces résultats aident aussi à mieux comprendre pourquoi un stimulus donné sera traité ou non dans le sommeil. (...)<br>Sleep can be defined as a behavioral state of rest in which consciousness of external stimuli vanishes and responsiveness to the environment is drastically reduced. When we sleep, however, we may still react and wake up to our name or to the alarm clock, suggesting that some processing of external stimuli remains. We address in the present work the question of how deeply external information is processed during sleep. We recorded brain activity in adult human subjects simultaneously in electro and magnetoencephalography (EEG and MEG) in response to auditory stimulation, before, during and after a short period of sleep. In order to test information integration through the brain hierarchy, we focused on hierarchical predictive coding capabilities, which enable the brain to anticipate the future from previous knowledge. Predictions occur at many if not all steps of the cortical hierarchy. Testing different levels of predictions enables us to assess the steps at which information integration is disrupted during sleep. We first tested the capacity of the sleeping brain to detect auditory novelty. We analyzed brain responses to violations of local and global temporal regularities, which are respectively reflected in EEG during wakefulness by two successive prediction error signals, the mismatch negativity (MMN) and the P300. Our analysis revealed that both the MMN and the P300 vanish during sleep, along with the loss of activations in prefrontal and parietal associative areas. The MMN gradually decreased in the descent to sleep, whereas the P300 vanished abruptly with the loss of awareness during N1 sleep. This all-or-none behavior strongly reinforces the hypothesis that the P300 is a marker of consciousness. Even so, we showed that sounds still activate sensory cortices, and that the brain remains able to detect new sounds and to habituate to them, but only in the limited context of sensory adaptation. Having demonstrated the disruption of predictive coding for arbitrary and newly acquired statistical regularities, in a second set of experiments we tested the capacity of the sleeping brain to develop predictions of future auditory stimuli for over-learned semantic knowledge stored in long-term memory. We presented sleeping subjects with simple arithmetic facts such as “two plus two is nine” and recorded brain responses to correct or incorrect results. We discovered that the sleeping brain was still able to detect arithmetic violations, with activations in part similar to wakefulness. We suggest that, although sleep disrupts explicit arithmetic computations, there is a preservation of prediction error signals for arithmetic facts stored in long-term memory. The present work clarifies the steps at which auditory information integration is disrupted during sleep, and which cognitive functions remain or vanish. The preservation of low-level sensory adaptation and of predictions from long term memory may account for the residual responsiveness that can be observed during sleep, while subjects are unconscious. Finally, these results also help to better understand why a given stimulus may or may not be processed during sleep. The depth of information integration is function of the ongoing spontaneous oscillations of the sleeping brain, but also of the nature of the stimulus, i.e. its salience, its knowledge, and its relevance

Earlier ages of alcohol initiation have been associated with an increased vulnerability for Alcohol Use Disorder and general risk taking behaviors beyond genetic influence. Reward processes, including reward anticipation (pleasure before receiving alcohol/general reward), reward learning (how quickly one pairs a stimulus with alcohol/general reward), and reward consummation (pleasure when receiving alcohol/general reward), have been implicated as potential mechanisms accounting for this vulnerability. However, no careful bio-behavioral research has been conducted on the effect of age of alcohol initiation on general and alcohol-related reward processes. Using Event Related Potentials (ERPs), the current study addressed this gap in a sample of 123 current alcohol drinkers. The Monetary Incentive Delay-General task and Monetary Incentive Delay-Alcohol task were administered to participants, in which reward learning (quickness of pairing the neutral cue or alcohol cue with monetary feedback), reward anticipation (activity to neutral cue or alcohol cue), and reward consummation (activity to monetary feedback) were examined. Electroencephalography was used to collect ERPs that index reward anticipation (P3) and reward consummation (P3 and Late Positive Potential) during these tasks. Earlier ages of alcohol initiation were associated with increased alcohol-related reward learning and decreased alcohol-related reward consummation (P3 and Late Positive Potential) beyond genetic and environmental covariates. There were no other significant relationships. These findings support and extend alcohol theories by showing that earlier ages of alcohol initiation may foster a greater sensitization in alcohol-specific reward-learning and more pronounced decreases in alcohol-related consummation. Although in need of direct testing, this might explain why earlier ages of alcohol initiation are associated with an increased vulnerability to Alcohol Use Disorder.

Event-related potentials have been found to be a useful indicator of brain states and brain abnormality. The contingent negative variation, P300 and bereitschafts potential are well researched event-related potentials of particular interest. Many factors have to be considered in the design of measurement systems to record multiple channels of these signals accurately. The correlation between channels must be high and channel noise and distortion must be minimal, whilst the system as a whole must meet the requirements of the medical safety standards. For further research there was found to be a requirement for a dedicated thirty-two channel ERP measurement system that met these criteria. This has been achieved in a PC based system that utilises simultaneous sampling of all channels, and filters that extend to very low frequencies. Software control of the system enables user adjustment of recording parameters and paradigm implementation. Data processing using high level software enables digital signal processing techniques to be applied for further noise removal and signal analysis. The system has been tested using synthetically generated signals and by limited recording of the three ERPs. The results prove that the system is a suitable tool for high accuracy, multi-channel recording of ERPs.

The capacity of the visual system to process information about multiple objects at any given moment in time is limited. This is because not all information can be processed equally or in parallel and subsequently reach consciousness. Previous research has utilized behavioural experiments to explore visual attention. More recently research, however, has used electroencephalography (EEG) to measuring the electrical brain activity in the posterior scalp. By time locking visual stimulus events to fluctuations in scalp activity researchers have been able to estimate the time course of attentional changes by measuring changes in these event-related potentials (ERP). One component in particular (N2pc) has been a reliable tool in measuring either the suppression of, or the shift of attentional to, both ignored and attended items in the visual scene. The N2pc is measured by comparing the ERP activity contralateral and ipsilateral to the visual field of interest. More recently, evidence has been presented that the mechanisms of attention thought to be represented by the N2pc (suppression and attentional selection) could be separated into different ERP components (Pd: indexing attentional suppression of an ignored item; and Nt: indexing attentional selection of the target) and measured independently. In six experiments, using ERPs, this thesis employs these components to explore the mechanisms and strategies of the human attentional system. Additionally, this thesis focuses on the impact of different types of simultaneous processing load on the attentional system and how the mechanisms of this system are influenced. Experiment 1 explores the idea that the type or valence of information to be ignored may influence the ability to suppress it. Results of this experiment 4 show that neither the type nor valence of the irrelevant information modulated the amplitude of the distractor positivity (Pd), indicating suppression of the irrelevant distractor was not altered. Noted in experiment 1 was also the presence of an early negativity (Ne) that appeared to represent attentional capture of the ignored lateral stimulus. Experiment 2 demonstrated that the valence of the lateral target did not alter the target negativity (Nt), indicating a different pattern of results between the Nt and the N2pc reported in previous studies (e.g. Eimer & Kiss, 2007; Feldmann-Wüstefeld et al., 2010). Experiment 2 also showed a similarity of the target negativity (Nt) to the early negativity (Ne; the N2pc like component observed in exp 1) toward face and non-face stimuli. This comparison supported the idea that the early negativity (Ne) reflected attentional capture of the ignored lateral distractor and as a result was relabelled the distractor negativity (Nd) in subsequent experiments. Experiment 3 showed that the salience of the lateral image did not modulate the Pd as should be the case if the Pd reflected sensory-level processing. An early contralateral negativity (similar to the Nd observed in exp 1) was altered by the salience of the distractor which added support to the hypothesis that this reflects attentional capture of the lateral ignored image. Experiment 4 attempted to manipulate working memory (WM) to assess the effect of WM load on attentional capture and suppression. While the results did indicate modulation of suppression under WM load, the limitations of the design of experiment 4 made any definitive interpretation of the results unreliable. The results of experiment 5 showed that suppression, as indexed by the Pd, was not altered by cognitive load. However, reductions in attentional capture under high cognitive load, as indexed by the distractor negativity (Nd), were observed and contradict the results of previous experiments (c.f. Lavie & De Fockert, 2005) 5 where cognitive load resulted in an increase in attentional capture. Although, there appears to be some issue in the authors interpretation of the results of these experiments (see chapter 6 for discussion). The results of Experiment 6 show the opposite effect with a significant increase in the laterality of the Pd under high perceptual load. A similar increase in the laterality of the Pd was not reflected in terms of valence though, where suppression of threat related distractors was not altered under high perceptual load. The hypothesis that an increase in perceptual load will result in a decrease in attentional capture was generally supported by the results of experiment 6. Under high perceptual load angry face distractors captured attention, as indexed by the laterality of the Nd, with neutral face distractors showing a reduction in attentional capture. While under low perceptual load, both angry and neutral face distractors resulted in a significant (and similar) laterality of the Nd. The thesis concludes by discussing issues concerning Lavie’s Load Theory of attention and outlines some potential misinterpretations of previous data that have led to the proposal that cognitive load results in a decrease in attentional resources and therefore a decrease in attentional capture of ignored stimuli. It is argued in this thesis that the results of Lavie and de Fockert (2005), which concluded that the increase in cognitive load resulted in a decrease in attentional capture, are more likely to be due to changes in attentional capture (i.e. a reduction) and changes in RT (i.e. an increase), under cognitive load being separate responses to the availability of resources, one that focusses attention on the goal directed task and the other that results in extended processing time to carry out the more difficult task. In this case both ‘changes’ appear to work to prioritise resources in favour of the goal directed task.

Plannings systems which can be considered as modules of an Enterprise Resource Planning system play a vital role in different types of organizations. The effects of the planning systems towards the Management Control Systems and organizational performance are less investigated in the context of not-for-profit/service providing organizations. This study sheds light on the effects of the planning systems on informal management controls and non-financial organizational performance by investigating the Swedish university sector through a case study performed at the Royal Institute of technology where the data were gathered using semi-structured interviews from different administrators using the planning systems. The study presents the effects of ten planning systems towards personnel controls, cultural controls and planning &amp; decision making controls. It further examines how the planning systems affect the personnel development, workplace relationships, employee satisfaction and other type of organizational performance measures. In this endeavour, the results of this study shows how the personnel controls affects the personnel development, cultural controls affects the workplace relationships and planning &amp; decision making controls affects the employee satisfaction, all in the light of different planning systems. Furthermore, it was also found out how different planning systems affect different organizational performance measures, namely, quality and efficiency of processes, quality of staff, employee health &amp; safety, gender equality, premises and infrastructure, student attractiveness, quality assurance, research &amp; education and external professional relationships. Finally this study generalizes the results found through investigating each planning system, which can be applied to the university sector/not-for-profit organizational sector in Sweden.<br>ME200X

The ability to express thought in language, to communicate, and to rapidly understand who did what to whom is a highly complex cognitive skill and ultimately the cognitive trait that defines us as being human. For the most part, language comprehension runs very smoothly and people perform it extremely quickly and efficiently. One might think this is nothing exceptional, were it not for the fact that everyday speech contains plenty of ambiguities, speech errors, and otherwise conflicting or interfering information. Similar to any other cognitive system, the language system is fitted out with mechanisms that detect conflicts and trigger compensating adjustments ‘on-the-fly’ in order to make sense of what has been said. Inevitably, language comprehension requires a combination of automatic and controlled processes and, depending on the context, we engage in both to varying degrees. Historically, linguistic conflict resolution has been investigated regarding to what extent linguistic modules such as ‘syntax’ and ‘semantics’ contribute to the process. In this thesis I take a step away from the traditional approach towards the question how the mechanisms underlying linguistic conflict resolution fit into domain-general cognition. It has been shown that controlled processing reliably results in activation of large-scale networks throughout the cortex. Importantly, neuroimaging studies have shown that the crucial brain region that enables us to flexibly make adjustments is the prefrontal cortex (PFC). In this thesis I present four case studies that investigated brain oscillations (as recorded in the EEG and MEG signal) in the time-frequency- (TFR), amplitude-time- (ERP), and source domain to determine how the language system relates to general executive functions. The materials employed structures that are amongst the most well-studied in psycholinguistic research: locally ambiguous garden-path sentences (e.g. “The nurse examined by the doctor was not on duty”), gender-agreement mismatches in anaphora and cataphora (e.g.“The king left London after reminding himself/herself about the letter”/ “After reminding himself/herself about the letter, the king left London.”), and syntactically complex garden-path sentences (“The receptionist realized that the nurse examined by the doctor was not on duty.”).The results in this thesis support the notion that there is indeed a connection between the language system and general executive functions during linguistic conflict resolution. Still, there are also situations where specialized ‘modules’ perform conflict resolution in a highly automatised fashion, particularly when contextual information sufficiently cues future input. However, as soon as increased uncertainty comes into play or capacity limits are reached, the brain appears to rely on extremely flexible mechanisms in prefrontal cortex regions.

Made available in DSpace on 2015-12-03T18:35:11Z (GMT). No. of bitstreams: 1 Mauro_Tadeu_Silveira_Lemos.pdf: 652964 bytes, checksum: 1057e3473b719608783e35257b9e88cc (MD5) Previous issue date: 2007-08-28<br>This work has as objective to confirm the importance of some aspects related to the implantation of systems of type ERP, searching to supply elements that subsidize managers, involved suppliers of solutions and executives in the administration of projects of implantation of Integrated Systems of Management. Its development had as base a research of field that involved 162 people, amongst users, managers of ERPs, suppliers of services and executives of companies who use systems as SAP, Oracle, Microsiga, Datasul, RM Sistemas and JDEdwards. These people had answered the questions related to the training of the users, envolvement and availability of the participant team of the implantation process, commitment of the directive body of the company, use of benchmark and definition of pointers that allow measuring the reached success. Also it was carried through interviews with users and managers of great companies in a qualitative boarding, in order to confirm the results of the quantitative research, as well as identifying to new information and suggestions of as it can be the shunting line administration eventual or imperfections during the implementation of integrated systems of management. Another boarded aspect in this work is the importance of the Controller in the implantation of system ERP, in part or during the entire project. This study it aims at, mainly, the control and metric used for accompaniment and alignment how much to the objective traced for the company in its decision of organizacional change with this new project<br>Este trabalho tem como objetivo confirmar a import??ncia de determinados aspectos relacionados ?? implanta????o de sistemas do tipo ERP, buscando fornecer elementos que subsidiem gestores, provedores de solu????es e executivos envolvidos na administra????o de projetos de implanta????o de Sistemas Integrados de Gest??o. Seu desenvolvimento teve como base uma pesquisa de campo que envolveu 162 pessoas, entre usu??rios, gestores de ERPs, provedores de servi??os e executivos de empresas que utilizam sistemas como SAP, Oracle, Microsiga, Datasul, RM Sistemas e JDEdwards. Essas pessoas responderam a quest??es relacionadas ao treinamento dos usu??rios, envolvimento e disponibilidade da equipe participante do processo de implanta????o, comprometimento do corpo diretivo da empresa, utiliza????o de benchmark e defini????o de indicadores que permitam mensurar o sucesso alcan??ado. Tamb??m foram realizadas entrevistas com usu??rios e gestores de grandes empresas numa abordagem qualitativa, a fim de confirmar os resultados da pesquisa quantitativa, bem como identificar novas informa????es e sugest??es de como pode ser a administra????o de eventuais desvios ou falhas durante a implementa????o de Sistemas Integrados de Gest??o. Outro aspecto abordado neste trabalho ?? a import??ncia da Controladoria na implanta????o do sistema ERP, em parte ou durante todo o projeto. Este estudo visa, principalmente, o controle e m??tricas utilizadas para acompanhamento e alinhamento quanto ao objetivo tra??ado pela empresa em sua decis??o de mudan??a organizacional com este novo projeto.

L'objectif général du présent travail de recherche était d'étudier les facteurs cognitifs responsables du déclin des performances arithmétiques avec le vieillissement. Plus précisément nous avons cherché à déterminer comment les mécanismes cognitifs à la base de la sélection stratégique (ie, capacité à adapter l'utilisation des stratégies) évoluaient au cours de la vie adulte. Dans cette perspective nous avons conduit une série d'études empiriques dans le domaine de la résolution de problèmes arithmétiques. Notre approche était double. Nous avons collecté, d'une part des données comportementales (temps de latence et pourcentages d'erreurs) et d'autre part, des données neurophysiologiques (potentiels evoqués, PEs et des mesures d'activation cérébrale à l'aide de l'imagerie par Résonance Magnétique fonctionnelle : IRMf). Les variations observées dans ces données en fonction des caractéristiques des problèmes et des différentes situations expérimentales (e. G. Surcharge en mémoire de travail) ont été comparées chez des participants sains , jeunes et âgés.

It is unclear whether or not older adults experience more difficulty managing cognitive conflict by inhibiting distracting stimuli and/or ignoring irrelevant information than younger adults. A common procedure used to measure inhibitory function is through the use of congruent and incongruent stimuli. Specifically, past literature that used tasks like the Simon and flanker have found differing effects on reaction times and various event-related potential (ERP) amplitudes and latencies, suggesting that either inhibitory function is a unitary mechanism or multifaceted. Moreover, research exhibits uncertainty for whether or not age influences deficits to inhibitory function. Another way to measure inhibitory deficits with these two tasks is through the use and measurements of conflict adaptation. Previous literature that have used such tasks support the notion that higher-conflict trials that precede lower-conflict trials result in smaller congruency effects, or what is known as conflict adaptation. While conflict processing has been associated with activity in the medial prefrontal cortex, it is typically considered a measure of the lateral prefrontal cortex and cognitive control. To date, no study has investigated age-related conflict processing and conflict adaptation effects between the Simon and Flanker tasks simultaneously. Therefore, the present study utilized an original combined Simon and flanker task to measure age-related inhibitory differences by measuring reaction time, accuracy, and various ERP (P1, N1, N2, P3) amplitudes to determine if older adults experience inhibitory deficits during the Simon and flanker tasks and whether inhibitory function is a unitary mechanism. Results of the present study indicate that older adults experience greater inhibitory deficits during cognitive conflict as compared to younger adults. Additionally, it was found that the combination of Simon and flanker effects significantly modulated inhibitory deficits for both age groups, but especially for older adults, as seen through both behavioral and electrophysiological means. Specifically, such deficits were most prominent during later processing (i.e. N2 and P3) as compared to early processing. Therefore, the study provides support for age-related changes in inhibitory function and conclude that inhibitory function is comprised of a unitary mechanism. Although these findings deem promising, future research should be conducted to provide conclusive evidence. Regardless, these findings are an important step towards better understanding how inhibitory function manifests and how older adults experience inhibitory deficits. Further, these results provide an initial framework into the identification and understanding of age-related changes during the normal aging process for the field of cognitive neuroscience.

The error related negativity (ERN) is an event-related brain potential that is sensitive to errors. It reflects individual differences in the extent to which individuals recruit neural systems involved in monitoring errors and systems for cognitive control that then make adjustments to future behavior. It has been closely linked to anxiety through diverse disorders and symptoms, but recently evidence highlights the role of anxious apprehension as a key individual difference related to error monitoring. Diverse hypotheses have emerged to explain this relationship. While some views emphasize the role of motivation and emotion, others suggest that a transient compensatory control is responsible for this relationship. Although both theories recognize the potential for state anxiety to potentiate the ERN, there is limited literature that allows a comparison of these competing hypotheses. The present study investigated the interaction of state and trait anxiety on the ERN by comparing ERN amplitude before and after a five minute worry induction period that specifically targeted each individual's greatest current worries. Results did not unequivocally support one specific theory, but rather provide some preliminary evidence of how trait and state worry may interact and affect the ERN. Suggestions for future research are provided, including using worry induction paradigms in which the worries increase threat or significance of errors.

This study examined the ability of reaction time (RT) and Event-Related Potentials (ERP) to detect malingered neurocognitive deficit (MNCD)in two new tasks compared to the TOMM (N = 47). Honest (HON), malingering (MAL), and traumatic brain injury (TBI) groups were compared on accuracy, RT and ERP measures. Overall, the Test of Memory Malingering (TOMM) accuracy was the most effective at classifying groups (hit rate = 100%). Several non-TOMM accuracy variables and RT variables reached hit rates in the range of 71%-88%. The TOMM RT variable had an unlimited time for participants to respond and was the most successful RT variable compared to the Old/New and Repetition Priming tasks that had a short time limit for participants to respond (approximately 1.5 seconds). The classic old/new effect RT pattern was evident for both the HON and TBI groups with significantly faster RTs for old items compared to new items. A logistic regression was employed to see if a RT and/or ERP variable added any unique prediction power in detecting malingering. The frontal-posterior ERP difference score had unique prediction power to detect malingering when classifying MAL vs. TBI (hit rate = 86%). In the Old/New task, ERP responses of HON produced greater activity in the frontal region compared to the posterior region. The opposite trend was found in TBI (posterior activity andgt; frontal) and MAL showed no significant difference.

Nous proposons d'explorer électrophysiologiquement la question de l'accès au sens. Pour cela, nous nous intéressons particulièrement à deux ERPs. La composante N400 est classiquement associée à la prise en compte d'un contexte sémantique. La composante P600, moins explorée, est retrouvée lors de tâches syntaxiques, sémantiques ou non spécifiquement linguistiques. Nous avons décrit trois études électrophysiologiques en conditions naturelles de langage. La première étude nous a permis de valider l'usage de ce matériel original dans une population contrôle. Puis nous avons proposé le transfert clinique de ce protocole en conditions naturelles de langage auprès de patients souffrant de TAB (deuxième étude) et de schizophrénie (troisième étude, en cours). Nous avons retrouvé une composante N400 préservée dans les TAB, alors que les patients souffrant de schizophrénie présentent un profil ERP altéré, avec une compréhension perturbée des mots comme congruents au contexte sémantique. Après nous être interrogés sur la notion de transfert clinique, et la prudence nécessaire à l'interprétation de ces résultats en pratique clinique quotidienne, nous avons envisagé deux autres approches relatives à l'accès au sens. D'une part, nous avons repris un modèle linguistique issu des perspectives phénoménologique, structuraliste et morphodynamique, pour détailler un protocole expérimental en cours de réalisation, ainsi que des premiers résultats exploratoires obtenus en population contrôle. D'autre part, les données en première personne après entretien d'explicitation apportent une illustration subjective des phénomènes d'accès au sens mis en jeu dans les deux protocoles utilisés<br>The aim of our projectwas to examine semantic access from an electrophysiological view. We specifically explored two Event-related Potentials (ERPs): N400, associated to semantic processing, and P600, associated to syntactic, semantic and non linguistic and general processes. In the first part of our project, we have explored these ERPs among healthy participants and psychiatric patients. People with schizophrenia exhibit thought and language disorders. In spite of common clinical manifestations with schizophrenia, patients with bipolar disorders (BDs) have rarely been assessed using neurolinguistic ERPs. We have conducted three electrophysiological studies in natural speech conditions. In the first study, we validated our original linguistic material among healthy participants. Then, in a clinical transfer perspective, we assessed manic patients suffering from BDs (second study) and patients with schizophrenia (third study, in preparation) using the same linguistic material. Our results support the hypothesis of a preserved N400 component in patients with BDs. On the contrary, preliminary results showed a disturbed N400 associated to congruent sentences among patients with schizophrenia.After discussing the limitations of the notion of clinical transfer and of our experimental studies, we also presented two alternative perspectives on speech comprehension. One the one hand, we described a linguistic model inherited from phenomenology, structuralism and morphodynamics. On the other hand, we reported first person data obtained through elicitation techniques. These experiential data enable us to better grasp semantic phenomena involved in our both experiments

In a set of behavioral, eye tracking, and ERP experiments, this thesis explored when and how object-state representation is established, maintained, and retrieved in language comprehension. We firstly examined whether different object-state representations could be established under two contrasting linguistic contexts (e.g., no change – “choose the ice cream” vs. change – “drop the ice cream”). Our findings showed that when linguistic context was provided, the representation that matched the consequences of described events was verified faster than the one that mismatched the expected outcome. Then, we studied the time course of establishing object-state representations with the visual world paradigm. Our results suggested that: a) the difference in looks towards the depicted versions of the situationally appropriate target object (an intact vs. a dropped ice cream) often manifested at the reference to the object but not prior to it; b) eye movements were primarily driven by semantic overlap between the visual display and the described object-state representation. Moreover, we found ERP evidence that was consistent with the need to keep track of, and retrieve object-state representations from episodic memory. We conclude that object-state representations were activated and retrieved during language processing. The work reported in this thesis highlights the need to take account of dynamics of event representation to capture the interplay between general semantic knowledge about objects and the episodic knowledge introduced by the sentential context in language comprehension.

The aim of the current series of experiments was to further explore the boundary conditions of the recognition memory old/new effect in the context of the recognition/associative recall task (Rugg, Schloerscheidt, Doyle, Cox, & Patching, 1996). The study by Rugg et al. was replicated and extended by manipulating both the semantic relatedness between study items and the timing of recall. Eventrelated potentials (ERPs) were recorded from 17 scalp electrode sites during performance of a recognition/associative recall task. Forty participants were visually presented with four blocks of 50 word pairs which were either unrelated (Experiments 1 and 2) or weakly semantically related (Experiments 3 and 4). Participants were instructed to form an association between the members of each word pair. At test, the first members of each pair were visually presented intermixed with a similar number of unstudied items. Participants were required to discriminate (i.e., recognise) previously studied items (old) from new items. Participants were also required to recall the study associate for words judged old, and to provide confidence levels for each recognition decision on a 3-point scale. Recall was either immediate (Experiments 1 and 3) or delayed (Experiments 2 and 4). Relative to ERPs to new items, the ERPs elicited by words correctly recognised and for which the associate was correctly recalled exhibited a positive-going shift between 500-800 ms poststimulus onset. The effect was maximal at posterior temporal-parietal electrode sites (the parietal old/new effect). Although the effect was not lateralised to the left hemisphere, this result may be due to the variability in encoding strategies employed by the participants. Behavioural data consistently indicated that response confidence is confounded with response category. The ERP results also revealed that the old/new effect is not evident following the experimental control of response confidence, and that immediate recall is associated with a negative-going shift at posterior electrode sites between 800-1100 ms poststimulus onset. Manipulating the semantic relatedness between the word pairs did not influence the distribution of the old/new effect. The results are discussed in terms of the view that the parietal old/new effect reflects neural activity associated with the recollection of specific previous experiences, and may reflect retrieval processes supported by the medial temporal lobe memory system (Moscovitch, 1992, 1994; Squire, 1992; Squire, Knowlton, & Musen, 1993). It is suggested that future research extend the current findings by examining the influence of response confidence in alternative recognition memory paradigms.

Neural activity is responsible for information processing in the brain. Activity has been found to have natural spatial modes, each of which has a frequency, analogous to the pitch of the notes of a musical instrument. A core aim of this thesis is to analyze large scale brain activity in terms of the eigenmodes of a brain hemisphere and to explore eigenmode dynamics. Electroencephalography (EEG) and evoked response potentials (ERPs) are important measurement techniques used to observe large scale changes in brain activity. EEG is a recording technique, while ERPs are transient electrical responses to brief sensory stimuli. In this thesis analysis of EEG and ERPs is carried out in terms of eigenmodes using an established physiologically based neural field theory, which averages over attribute of neurons to yield a continuum model of brain activity whose parameters are based on the physiology. To explore the effects of boundary conditions and topology, a spherical approximation is used and compared with prior work on planar geometry; we also analyze ERP numerically in the convoluted cortex to find how brain activity is affected by folding. Chapter 1 provides an overview of the background and structure of the thesis, covering basic anatomy of the brain, neuron structure and dynamics, measurements of brain activity, EEG, ERP, eigenmode decomposition of brain activity, and large scale brain modeling using neural field theory. Chapter 2 applies an established corticothalamic neural field theory to spherical geometry to understands how geometry affects measures of the brain activity such as the power spectrum, coherence, and correlation using spherical harmonics. Equations for modal dynamics, spectra, correlations, and coherence are found from this model. These equations explain how modal dynamics and corticothalamic resonance depend on the geometry and affect experimental observations. The main findings include an exploration of the spherical modal structure, understanding of the number of modes that contribute significantly to brain activity, and analysis of the effects of the finite spatial extent of the cortex. It is stressed that only a few spatial eigenmodes are needed for an accurate representation of macroscopic brain activity. In Chapter 3 we analyze ERPs analytically and numerically using spherical geometry via neural field theory. In this work we also compare results in planar geometry and spherical geometry. It is found that the ERP peak is slightly delayed at large angles from the stimulus point due to the axonal conduction delays, which cause increasing delays as distance increases from ϑ=0, and it is corresponding to group velocities of 6 - 10 ms-1. During propagation spreading and damping reduce the amplitude. Corticothalamic modal effects are explored and, as in Chap. 2, it is found that a handful modes are responsible for explaining the basic features of the ERPs.

The long-term memory system for what is conscious and can be verbalized – declarative memory- is often separated into memory for general facts and memory for personal events (Squire, 2009; Tulving, 2002). Personal semantics share elements of both semantic memory (i.e., they are facts that can be known) and episodic memory (i.e., they are self-related and idiosyncratic; Renoult, Davidson, Palombo, Moscovitch, & Levine, 2012). According to the taxonomy of personal semantics (Renoult et al., 2012), they vary in proximity to either semantic or episodic memory. Towards one end of the continuum, memory for autobiographical facts such as jobs and names of friends were hypothesized to be closer to general facts. Towards the other end of the continuum, repeated events are summaries of the core elements of similar events that happened more than once (e.g., getting coffee at a coffee shop), and they were hypothesized to be closer to episodic memory (i.e., the recollection of a unique event). Self-knowledge involves self-reflection about one’s own personality traits and preferences; it was thought to be the most distinct from semantic and episodic memory. However, little research had compared personal semantics to both semantic and episodic memory, or to one another, and these proposals needed to be tested experimentally. In this thesis, I compared the neural correlates of three types of personal semantics to semantic memory (study 1, 2, 3) and episodic memory (study 1, 2), and to one another (study 1) using functional magnetic resonance imaging (fMRI; study 1) and event related potentials (ERPs; study 2, 3). Moreover, I examined whether temporal orientation modified the personal semantics’ relationship to the typically atemporal semantic memory (study 2, 3) and to the typically past-oriented episodic memory (study 2). In study 1, general facts, autobiographical facts, repeated events, and unique events were compared using fMRI, in a follow-up to an ERP study (Renoult et al., 2016). In our analyses of the hippocampus (HPC) and posterior medial network (Ritchey, Libby, & Ranganath, 2015), general semantics and autobiographical facts were often not significantly different from one another (except for the left posterior HPC), and repeated events and unique events did not differ from one another in any comparison. I observed a small graded increase of brain activity from general facts to autobiographical facts to repeated events and unique events (with a significant linear trend) in the left posterior HPC. In contrast, no memory type differed in the anterior temporal network (Ritchey et al., 2015). In study 2 and 3, self-knowledge was operationalized as the knowledge of one’s own traits, and could concern past (study 2), present (study 2, 3) and future selves (study 2, 3). A neural correlate of recollection, the Late Positive Component (LPC), had a larger mean amplitude for thinking about the self than others (study 2, 3), and thinking about a past and/or future self than the present self (on average for study 2, and significant for study 3). The amplitude of the LPC for thinking about the past and future selves did not differ from an episodic recognition memory task (or present self-knowledge; study 2). Further, the temporal orientation effect was smaller and not significant when we compared thinking about the present and the future traits of others (study 3). The operationalization of the “other” as a close friend or a group of people did not modify this result (study 3). Together, in addition to Renoult et al. (2016), these findings suggest that: the neural correlates of autobiographical facts, repeated events, and self-knowledge do not overlap perfectly with semantic or episodic memory. Moreover, the temporal orientation of the knowledge is one factor that can influence the proximity of the neural correlates of personal semantics to either semantic or episodic memory.

The present study sought to investigate the effects of meditation practice on the neural mechanisms of attention and self-monitoring by comparing a group of experienced meditators to matched controls. Self-report measures of mindfulness and self-compassion were assessed to examine whether meditation-related improvements in attention and self-monitoring were linked to increases in these qualities. Thus, differences between groups (meditator versus control) on all variables and relationships among variables (attention, self-monitoring, self-compassion, and mindfulness) were explored. Results indicate that individuals with meditation experience showed enhancement in neural networks related to selective attention and attentional allocation, as evidenced by larger P1/N1 and P3b amplitudes, relative to controls. Meditators also showed improved self-monitoring of their errors, as indexed by enhanced Pe amplitudes, when compared to controls. Importantly, greater number of years of meditation experience was linked to larger Pe amplitudes, providing evidence that more practice with meditation was associated with greater error awareness. At the same time, meditators showed greater levels of mindfulness and self-compassion when compared to controls. Importantly, each of the neural indices was linked to greater levels of mindfulness and self-compassion. Specifically, self-kindness was correlated with each of these ERP components and to percentage of alpha power during meditation, and the mindfulness facet of observing fully mediated the relationship between meditation experience and P1 amplitudes. These findings suggest that the qualities that are enhanced with meditation are associated with enhancements in attentional control and awareness of errors. This study is an exciting step toward future intervention studies that combine multiple sources of information (self-report, neural measures, and behavior) to clarify the nature of the associations among these variables so that the mechanisms of mindfulness can be more fully understood.

La reconnaissance experte de l'expression faciale est cruciale pour l'interaction et la communication sociale. Le comportement, les potentiels évoqués (ERP), et les techniques d’oculométrie peuvent être utilisés pour étudier les mécanismes cérébraux qui participent au traitement visuel automatique. La reconnaissance d'expressions faciales implique non seulement l'extraction d'informations à partir de caractéristiques faciales diagnostiques, stratégie qualifiée de traitement local, mais aussi l'intégration d'informations globales impliquant des traitements configuraux. Des nombreuses recherches concernant le traitement des informations faciales émotionnelles il apparaît que l’interaction des traitements locaux et configuraux pour la reconnaissance des émotions est mal comprise. La complexité inhérente à l'intégration de l'information faciale est mise en lumière lorsque l'on compare la performance de sujets sains et d’individus atteints de schizophrénie, car ces derniers ont tendance à s’attarder sur quelques éléments locaux, parfois peu informatifs. Les différentes façons d'examiner les visages peuvent avoir un impact sur la capacité socio-cognitive de reconnaître les émotions. Pour ces raisons, cette thèse étudie le rôle des caractéristiques diagnostiques et configurales dans la reconnaissance de l'expression faciale. En plus des aspects comportementaux, nous avons donc examiné la dynamique spatiale et temporelle des fixations à l’aide de mesures oculométriques, ainsi que l’activité électrophysiologique précoce considérant plus particulièrement les composantes P100 et N170. Nous avons créé de nouveaux stimuli des esquisses par une transformation numérique de portraits photos en esquisses, pour des visages exprimant colère, tristesse, peur, joie ou neutralité, issus de la base Radboud Faces Database, en supprimant les informations de texture du visage et ne conservant que les caractéristiques diagnostiques (yeux et sourcils, nez, bouche). Ces esquisses altèrent le traitement configural en comparaison avec les visages photographiques, ce qui augmente le traitement des caractéristiques diagnostiques par traitement élémentaire, en contrepartie. La comparaison directe des mesures neurocognitives entre les esquisses et les visages photographiques exprimant des émotions de base n'a jamais été testée, à notre connaissance. Dans cette thèse, nous avons examiné (i) les fixations oculaires en fonction du type de stimulus, (ii) la réponse électrique aux manipulations expérimentales telles que l'inversion et la déconfiguration du visage. Concernant, les résultats comportementaux montrent que les esquisses de visage transmettent suffisamment d'information expressive (compte tenu de la présence des caractéristiques diagnostiques) pour la reconnaissance des émotions en comparaison des visages photographiques. Notons que, comme attendu, il y avait un net avantage de la reconnaissance des émotions pour les expressions heureuses par rapport aux autres émotions. En revanche, reconnaître des visages tristes et en colère était plus difficile. Ayant analysé séparément les fixations successives, les résultats indiquent que les participants ont adopté un traitement plus local des visages croqués et photographiés lors de la deuxième fixation. Néanmoins, l'extraction de l'information des yeux est nécessaire lorsque l'expression transmet des informations émotionnelles plus complexes et lorsque les stimuli sont simplifiés comme dans les esquisses. Les résultats de l’électroencéphalographie suggèrent également que les esquisses ont engendré plus de traitement basé sur les parties. Les éléments transmis par les traits diagnostiques pourraient avoir fait l'objet d'un traitement précoce, probablement dû à des informations de bas niveau durant la fenêtre temporelle de la P100, suivi d'un décodage ultérieur de la structure faciale dans la fenêtre temporelle de la N170<br>Proficient recognition of facial expression is crucial for social interaction. Behaviour, event-related potentials (ERPs), and eye-tracking techniques can be used to investigate the underlying brain mechanisms supporting this seemingly effortless processing of facial expression. Facial expression recognition involves not only the extraction of expressive information from diagnostic facial features, known as part-based processing, but also the integration of featural information, known as configural processing. Despite the critical role of diagnostic features in emotion recognition and extensive research in this area, it is still not known how the brain decodes configural information in terms of emotion recognition. The complexity of facial information integration becomes evident when comparing performance between healthy subjects and individuals with schizophrenia because those patients tend to process featural information on emotional faces. The different ways in examining faces possibly impact on social-cognitive ability in recognizing emotions. Therefore, this thesis investigates the role of diagnostic features and face configuration in the recognition of facial expression. In addition to behavior, we examined both the spatiotemporal dynamics of fixations using eye-tracking, and early neurocognitive sensitivity to face as indexed by the P100 and N170 ERP components. In order to address the questions, we built a new set of sketch face stimuli by transforming photographed faces from the Radboud Faces Database through the removal of facial texture and retaining only the diagnostic features (e.g., eyes, nose, mouth) with neutral and four facial expressions - anger, sadness, fear, happiness. Sketch faces supposedly impair configural processing in comparison with photographed faces, resulting in increased sensitivity to diagnostic features through part-based processing. The direct comparison of neurocognitive measures between sketch and photographed faces expressing basic emotions has never been tested. In this thesis, we examined (i) eye fixations as a function of stimulus type, and (ii) neuroelectric response to experimental manipulations such face inversion and deconfiguration. The use of these methods aimed to reveal which face processing drives emotion recognition and to establish neurocognitive markers of emotional sketch and photographed faces processing. Overall, the behavioral results showed that sketch faces convey sufficient expressive information (content of diagnostic features) as in photographed faces for emotion recognition. There was a clear emotion recognition advantage for happy expressions as compared to other emotions. In contrast, recognizing sad and angry faces was more difficult. Concomitantly, results of eye-tracking showed that participants employed more part-based processing on sketch and photographed faces during second fixation. The extracting information from the eyes is needed when the expression conveys more complex emotional information and when stimuli are impoverished (e.g., sketch). Using electroencephalographic (EEG), the P100 and N170 components are used to study the effect of stimulus type (sketch, photographed), orientation (inverted, upright), and deconfiguration, and possible interactions. Results also suggest that sketch faces evoked more part-based processing. The cues conveyed by diagnostic features might have been subjected to early processing, likely driven by low-level information during P100 time window, followed by a later decoding of facial structure and its emotional content in the N170 time window. In sum, this thesis helped elucidate elements of the debate about configural and part-based face processing for emotion recognition, and extend our current understanding of the role of diagnostic features and configural information during neurocognitive processing of facial expressions of emotion

With increased age, some individuals experience cognitive declines that are more severe than what is observed in healthy cognitive aging. This decline may be related to mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Much of the current research on dementia attempts to detect subtle cognitive and memory declines before behavioral and cognitive symptoms are more apparent. Intense research interest has focused on MCI, a condition that includes impairment in some areas of cognitive functioning but is not severe enough to warrant the diagnosis of dementia. MCI may represent a transitional stage between healthy aging and AD and is considered a risk factor for AD development. The purpose of the present thesis was to examine if EEG and ERPs can be used as reliable predictors of cognitive changes in aging and MCI. Study 1 was designed to examine if there is evidence of changes in the EEG between cognitively healthy older adults and people with MCI. The purpose of this study was to examine differences in EEG activity between healthy older adults and people with MCI during early and late portions of a longer-than-normal resting-state recording. Resting state recordings typically last 1-3 minutes. It would be advantageous to run a longer testing session because this would provide more data, but such a procedure might be problematic because it might result in increased drowsiness in the latter half of testing. If this drowsiness affected those with MCI more than healthy adults, this might produce artifactual differences between groups. If increased drowsiness occurs as the duration of the recording becomes longer, an increase of low-frequency EEG activity should be observed, particularly in the delta band. Resting state EEG was recorded in 20 healthy older adults and 20 people with MCI who rested with their eyes closed. The EEG recording was divided into two three-minute halves. People with MCI exhibited a significant increase in theta power density over posterior regions of the scalp compared to healthy older adults. Power density for all frequency bands did not change over the two halves of the recording. That is, there was little evidence of drowsiness in the second half of the recording. Taken together, these findings indicate that longer resting-state EEG recording can be reliably employed without increased risk of drowsiness. Study 2 examined whether there is evidence of a dysfunction in the salience network in older adults. Previous research suggests that older adults may be less able to compute the level of salience of unattended stimulus inputs. The transient detector system is a specialized network of brain areas for detecting sudden changes in the intensity of an auditory stimulus. The output of this system, as reflected by the auditory ERP components N1 and P2, provides a measure of the level of salience of the stimulus. Twenty younger adults and healthy older adults participated in this study. A single auditory stimulus was presented rapidly, every 1.5 s, or very slowly, every 12 s, in different conditions. When the stimuli were presented rapidly, group differences were not observed for the amplitudes of N1 and P2, peaking at 100 and 180 ms, respectively. When stimuli were presented very slowly, their amplitudes were greatly enhanced for younger adults but did not increase for older adults. The failure to observe a large increase in the amplitude of N1 and P2 in older adults for very slowly presented stimuli provides strong evidence of a dysfunction of the salience network in this group. There is evidence that both the functioning of salience network and the frontoparietal network deteriorate in cognitively healthy older adults. These networks might further deteriorate in people with MCI. In study 2, when stimuli were presented slowly, the P2 was delayed and peaked at a time that is more consistent with a P3a. The P3a is elicited by a potentially highly salient, but unattended stimulus input that interrupts the functioning of the frontoparietal network, resulting in a switch of processing priorities away from current task demands and toward the processing of the stimulus input. In study 3, auditory stimuli were again presented either rapidly or very slowly to 20 healthy older adults and 20 people with MCI. The amplitude of N1 did not differ between the two groups in either the fast or slow conditions. Thus, there is little evidence that people with MCI have a deficit in computing the salience of unattended auditory stimuli. When stimuli were presented slowly, the P2/P3a was significantly smaller in people with MCI compared to healthy older adults. The attenuated P2/P3a in people with MCI may reflect a reduced frontoparietal ability to determine processing priorities. In people with MCI, priority of processing may not be switched from the ongoing cognitive task to the potentially much more relevant auditory input. In the results of studies 2 and 3, there was ambiguity regarding whether the positivity observed in the slow condition reflected P2 or P3a activity. A more definite P3a had been elicited in oddball paradigms. In the oddball paradigm, the participant is presented with a sequence of frequently presented homogenous standard stimuli. At rare and unpredictable times, a deviant is presented, the deviant representing a change in a feature of the standard. Deviants that represent a large change from the standard may elicit a P3a. Two experiments were run in which at least one of the deviants had previously been shown to elicit a large P3a in younger adults. Study 4 consisted of two experiments. In Experiment 1, the deviants represented either decreases or increases in the intensity of the standard. The deviant that represented an increase in intensity has been found to elicit a large P3a in previous studies. In Experiment 2, six different deviants were presented. The deviants included a white noise burst and environmental sounds, both of which have elicited a large P3a in previous studies. Across both experiments, the MMN/DRN and P3a did not differ between healthy older adults and people with MCI. Previous studies have indicated that the P3a is reduced in amplitude in healthy older adults compared to younger adults. The results of study 4 indicate that the P3a was not further reduced in people with MCI. This is in contrast to study 3 in which the P2/P3a was reduced in people with MCI. This could be because of the use of the oddball paradigm in study 4. Detection of the deviant would be carried out, at least in part, by the change detection system while in study 3, the presentation of a single stimulus would have been detected only by the transient detection system. Operations of the frontoparietal network controlling processing priorities can be interrupted by sufficient output from either the transient or change detector systems. This results in a switch of processing from an ongoing task to the processing of the potentially more relevant stimulus input. When this interrupt is sent from the change detection system, the operations of the frontoparietal network do not appear to deteriorate in people with MCI compared to what is observed in cognitively healthy older adults.

What are the effects of non-balanced bilingualism on cognitive performance? And how do proficient, non-native speakers acquire and use lexical, syntactic and semantic information during sentence processing? Whilst there is growing research on these topics, there is no firm consensus on how to answer these questions. In the literature on cognitive effects of bilingualism, this lack of consensus has even resulted in radically opposing views and a heated debate. In this thesis, I seek to provide a balanced treatment of the literature and to address the above-mentioned questions by employing behavioral and neurophysiological paradigms. First, using a structural priming paradigm, I examine how proficient, non-native speakers of different native language backgrounds (Romance and Germanic) acquire lexically-specific syntactic restrictions of non-alternating verbs in English. Results from these experiments suggest that, although non-native speakers partially acquire lexically-specific syntactic restrictions, their knowledge is not native-like. Moreover, transfer from the first language does not seem to play a role in the acquisition of the relevant restrictions. Second, using Event-Related Potentials (ERPs) I examine whether proficient non-native Spanish-English speakers draw on different forms of semantic information such as relatedness and animacy incrementally during sentence comprehension. Results of these experiments suggest that, while relatedness facilitates processing (indexed by N400s) in both native and non-native speakers, effects of animacy are smaller in non-native speakers, relative to native speakers. Third, I employ a series of auditory attentional tasks and measures of lexical access and verbal fluency to assess cognitive functions in non-balanced bilinguals with different levels of language proficiency. Results show a bilingual advantage in inhibitory control and a non-significant trend towards bilingual better performance in attentional switching, and the groups exhibit similar performance on verbal fluency. Results of all the studies are discussed in the context of the existing literature on cognitive performance in bilinguals and accounts of language processing in native and non-native speakers and suggestions for future research are provided.

Este trabalho tem como objetivo desenvolver um roteiro que auxilie as pequenas e médias empresas (PMEs) a adotarem os sistemas ERPs (ENTERPRISE RESOURCE PLANNING) como ferramenta de mudança organizacional. As PMEs, antes de decidirem sobre a aquisição de um ERP, necessitam fazer uma análise da solução que se considere a mais adequada para seus problemas, procurando garantir que os investimentos, escassos neste setor, tragam os benefícios esperados. Elas devem avaliar os impactos que o sistema acarretará e as mudanças incorridas por sua introdução e seu uso. Para atingir o objetivo mencionado, realizou-se, primeiramente, um estudo bibliográfico, focalizando-se os seguintes temas: mudança organizacional, sistemas ERPs e pequenas e médias empresas. Após este estudo, conduziu-se um trabalho de campo, em duas etapas. A fase I consistiu em uma pesquisa de campo exploratória, que possibilitou identificar os sistemas ERPs existentes no mercado bem como as PMEs, situadas na região da grande São Paulo, que os utilizam. A fase II compreendeu um estudo de casos, implicando observação direta intensiva combinada com a aplicação de um roteiro que envolveu duas empresas, selecionadas dentre as estudadas na fase I, para análise mais detalhada. Como resultado final, apresenta-se um roteiro desenvolvido para guiar as decisões das PMEs referentes à adoção de sistemas ERPs, no contexto da mudança organizacional. Como contribuição da pesquisa fornecem-se subsídios que os empresários das PMEs podem utilizar em suas decisões sobre a aquisição de ERPs, evitando iludirem-se pelo \"modismo\" administrativo e empresarial do momento, e informações que os fabricantes deste tipo de solução podem usar na identificação de possíveis carências das PMEs, não contempladas pelos sistemas disponíveis atualmente.<br>This thesis aims to develop a plan in order to help small and medium enterprises (SMEs) to adopt the Enterprise Resource Planning (ERP) as a tool for organizational change. Before deciding about te ERP\'s adoption, SMEs need to carry out a deep analysis about which solution better fits their problems, thus aiming to guarantee that investments, which are scarce in this sector, may bring the expected benefits. Besides this analysis about the necessary investments, SMEs should evaluate the impacts the system will cause, as well as the changes incurred by its introduction and use. In order to reach this objective, we first carried out a bibliographical study about the following subjects: organizational change, ERP systems and SMEs. After this study, we conducted a field research, carried through in two steps. The first step, which we called Preliminary Survey, has consisted in an exploratory field research, where we identified the ERP systems that were avaiable in the market as well as some SMEs, located in the São Paulo region, that utilized these systems. In the second step we made a field research, through intensive direct observation combined with the applying of the plan we developed in this work. In this second phase, we picked up two enterprises, among those studied in the first step, and they were analyzed in a more detailed way. As a final result, we present a plan developed to guide the decisions of SMEs in which relates the adoption of ERPs systems, in the context of organizational change. As a contribution of the research we will propose some subsidies aiming to help SMEs\'businessmen in their decisions about the acquisition of ERPs, avoiding being deluded by \"managerial fads\"; we will also present some information that ERPs producers may utilize in order to identify possible lacks, not contemplated by current avaiable ERPs systems.

The present work contributed to our understanding of the neurocognitive mechanisms underlying pain modulation through sensory, attentional, emotional and cognitive processes. We used subjective, behavioral, and electrophysiological indexes to reveal the effects of body position, emotions, placebo expectations and cognitive reappraisal on subjective pain experience and pain-related somatosensory potentials. Four studies were conducted to investigate different forms of pain modulation. Study 1 tested the hypothesis that the horizontal body position reduces pain perception and cortical pain processing. We demonstrated that the supine vs. sitting body position was associated with dampened perception of non-painful stimuli and inhibited cortical late processing (300-600 ms) of non-painful and painful stimuli, related to neural activity within frontal right regions (anterior cingulate cortex and superior frontal gyrus). Study 2 investigated gender differences in the emotional modulation of pain. Although males and females did not differ at the behavioral level and reported reduced pain ratings only during the visual perception of erotic pictures, striking gender differences emerged in the N2 and P2 potentials, elicited by painful stimuli. Males showed inhibited cortical processing of pain stimuli when viewing erotic pictures only, whereas females showed a differentiated cortical pain modulation for each emotional content took into consideration (erotic vs. sport/adventure vs. neutral vs. fear/threat vs. mutilation pictures), in particular for N2 potentials. In Study 3, we examine the role of individual beliefs on the effectiveness of a traditional and a homeopathic analgesic treatment. We utilized a deceptive paradigm, i.e., neither the participants nor the experimenters were aware that the administered treatment was an inert substance. We found that only the participants who took a treatment that was coherent with their beliefs showed a reduced cortical pain processing, indicated by dampened P2 amplitudes. Finally, Study 4 demonstrated that healthy participants are able to modify their pain experience using an imaginary-based reappraisal strategy. Perceived pain intensity and unpleasantness were either reduced or enhanced with respect to a neutral condition, and an effective pain inhibition was associated with increased N2 and decreased P2 amplitudes<br>Il presente lavoro di ricerca ha contribuito alla comprensione dei meccanismi neurocognitivi sottostanti alla modulazione del dolore da parte di processi sensoriali, attenzionali, emozionali e cognitivi. Abbiamo preso in considerazione indici soggettivi, comportamentali ed elettrofisiologici per rilevare gli effetti della posizione del corpo, delle emozioni, delle aspettative legate al placebo, e del reappraisal cognitivo sull’esperienza soggettiva del dolore e sui potenziali somatosensoriali dolore-relati. Quattro studi sono stati condotti per indagare differenti tipologie di modulazione del dolore. Lo Studio 1 ha testato l’ipotesi che la posizione orizzontale del corpo riduca la percezione e l’elaborazione corticale del dolore. Abbiamo dimostrato che la posizione del corpo supina vs. seduta era associata ad una diminuita percezione di stimoli non dolorosi e ad una inibita elaborazione corticale tardiva (300-600) di stimoli dolorosi e non dolorosi, relata ad attività neurale in regioni frontali destre (corteccia cingolata anteriore e giro frontale superiore). Lo Studio 2 ha indagato le differenze di genere nella modulazione emozionale del dolore. Sebbene maschi e femmine non differissero a livello comportamentale e mostrassero ridotti punteggi di dolore solamente durante la visione di immagini erotiche, delle notevoli differenze di genere sono emerse nei potenziali N2 e P2 elicitati da stimoli dolorosi. I maschi avevano mostrato una inibita elaborazione corticale del dolore solamente durante la visione di immagini erotiche, mentre le femmine hanno mostrato una modulazione corticale del dolore diversificata per ogni contenuto emozionale preso in considerazione (immagine erotiche vs. sport/avventura vs. neutre vs. paura/minaccia vs. mutilazione), in particolare per la N2. Nello Studio 3, abbiamo esaminato il ruolo delle credenze individuali nell’efficacia di un trattamento analgesico tradizionale e di uno omeopatico. Abbiamo utilizzato un paradigma decettivo, i.e., né i partecipanti, né le sperimentatrici erano a conoscenza che il trattamento somministrato era una sostanza inerte. Abbiamo trovato che solamente i partecipanti che assumevano un trattamento che era coerente con le loro credenze mostravano una ridotta elaborazione corticale del dolore, indicata da diminuite ampiezze della P2. Infine, lo Studio 4 ha dimostrato che i partecipanti sani sono in grado di modificare la propria esperienza del dolore, utilizzando una strategia di reappraisal cognitiva che fa uso di immagini mentali. L’intensità di dolore percepita era o diminuita o aumentata rispetto ad una condizione neutra e un’efficace inibizione del dolore era associata ad incrementate ampiezze N2 e diminuite ampiezze P2

Submitted by Elba Lopes (elba.lopes@fecap.br) on 2016-03-16T13:41:45Z No. of bitstreams: 2 Lavio_Falcao_Costa_de_Oliveira.pdf: 562663 bytes, checksum: 2007541cdd14b8882c600047bb955d18 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5)<br>Made available in DSpace on 2016-03-16T13:41:45Z (GMT). No. of bitstreams: 2 Lavio_Falcao_Costa_de_Oliveira.pdf: 562663 bytes, checksum: 2007541cdd14b8882c600047bb955d18 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-10-14<br>This research examines the effect of Enterprise Resource Planning (ERP) adoption on the financial performance of 87 Brazilian companies listed on the Sao Paulo Stock Exchange (BMF&BOVESPA), compared with a group of 43 companies that have not adopted the system at the analyzed period of time. This study is a replication of Hunton et al. (2003) research to the reality of the Brazilian marketplace and evaluates the ROA (Return on Assets), ROS (Return on Sales), ATO (Asset Turnover) and ROI (Return on Investments) profitability indicators, controlling for size and financial health. Results, in general, indicated no significant performance differences between the time before and after the implementation of ERP systems, which indicated that the ROA, ROI and ACT were significantly better for ERP adopters.<br>Esta pesquisa examina o efeito da ado????o de sistemas Enterprise Resource Planning (ERP) sobre o desempenho financeiro de 87 empresas brasileiras listadas na Bolsa de Valores do Estado de S??o Paulo (BM&FBOVESPA), comparado com um conjunto de 43 empresas que n??o adotaram o sistema no per??odo de tempo analisado. Este estudo ?? uma replica????o da pesquisa de Hunton et al. (2003) para a realidade do mercado Brasileiro e avalia os indicadores de rentabilidade ROA (Return on Assets), ROS (Return on Sales), ATO (Asset Turnover) e ROI (Return on Investments), controlando o porte e sa??de financeira das empresas. Os resultados, de maneira geral, n??o indicaram significante diferen??a de desempenho entre o per??odo anterior e posterior ?? implanta????o dos sistemas ERP, divergindo da pesquisa de Hunton et. al (2003) que indicou que o ROA, ROI e ATO foram significativamente melhores para empresas que adotaram o ERP.

ERPs are expensive and widely adopted approaches to systems integration. However in both the corporate sector and the public sector ERPs implementations have been very problematical, with reports of widespread failure or only partial success. Very little research has been carried out into ERPs in the higher education sector and most of these have primarily taken the „business‟ perspective; the effects on the academic and service (student administration) domains have been overlooked. Furthermore, with the increasing corporatisation of universities and their expansion into the overseas student market, considerable tensions have arisen which make the implementation of an integrated system which meets the needs of all major stakeholders, particularly difficult. Since all large scale systems projects involve considerable change and information systems research shows that these changes are frequently met with resistance, it is proposed that a political perspective is useful to investigate the origins and effects of political behaviour. Recent reviews have argued that there is a need for a detailed explanation of how power influences information systems implementations and to further refine power related concepts. To address these shortcomings a multidimensional conceptual model is utilised which situates power and politics at the interpersonal and group level within the context of influences created by social, structural and technological movements. The use of French and Raven‟s (1959) theory of power bases and the Power/Interaction model developed by Raven (1992) allows the „influence‟ attempt to analysed in detail, including the motivation, selection of power bases, preparation for the attempt and assessment of success. This clarifies the way that influence attempts are carried out within the context of information systems implementation and provides a model which would be useful for future research The focus of the study is on the experiences of the service oriented student administration staff in a large Australian university. This group has not been studied in relation to ERP implementation, even though they represent the point of tension between the academic and corporate domains. In order to understand the context of their experiences, a qualitative approach is taken, to obtain a rich description of the case. Because the implementation of ERPs remains largely unchallenged, a critical stance is adopted which seeks to explore the dominant discourse.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Information and Communication Technology<br>Science, Environment, Engineering and Technology<br>Full Text

Mestrado em Gestão de Sistemas de Informação<br>Apesar de toda a literatura publicada sobre a melhoria da qualidade de dados, problemas de qualidade de dados continuam a afetar a operacionalidade das empresas e dos seus sistemas de decisão. Reconhecendo este facto, a RetailPC, uma empresa de comércio a retalho de equipamento informático, aceitou a realização da presente investigação, a qual teve como objetivo a avaliação e melhoria da qualidade de dados da sua entidade Cliente, durante um processo de migração de dados entre dois ERPs (Primavera Professional para SAP Business One). Para o efeito, foi utilizada a metodologia Action Research, uma vez que permite ao investigador assumir um papel intervencionista na resolução do problema da qualidade de dados. No caso concreto deste trabalho, foi avaliada e melhorada a qualidade de dados durante a migração entre ERPs e alterados processos de recolha dos mesmos, tendo sido disponibilizados meios de diagnóstico para futuros ciclos de Action Research. No final, foi possível constatar que a qualidade de dados foi melhorada significativamente. Foi possível corrigir todos os erros detetados nos atributos ShipType (Modo de expedição), PymCode (Formas de pagamento), Currency (Moeda) e LangCode (Língua da documentação enviada para o cliente); 98,53% dos erros detetados em sujeitos passivos coletivos com respeito ao atributo LicTradNum (NIF); 56,67% das moradas com erros do atributo ZipCode (Código Postal) e 99,65% dos tuplos que continham valores no atributo IntrntSite, uma vez estava a ser utilizado para um fim diferente do previsto pelo ERP, tendo esses valores sido migrados para o atributo E_Mail para posterior tratamento.<br>Despite all the published literature on data quality enhancement, data quality problems continue to affect the company's operation and their decision systems. In recognition of that, RetailPC, an IT equipment retail trading company, accepted to be part of the present research, which aimed the assess and improve data quality of its Customer entity during a data migration process between ERPs (Primavera Professional to SAP Business One). For this purpose, it was used the Action Research methodology, as it allows the researcher to assume an interventional role in the resolution of the data quality problem. In the specific case of this research, has been assessed and enhanced data quality during data migration and changed data collection processes, were made available diagnostic methods for future cycles of Action Research. At the end it was perceived that the quality of data is improved significantly. It was possible to correct all the errors detected in attributes ShipType (Delivery mode), PymCode (Payment Methods), Currency (Currency) and LangCode (Language of documents sent to customer); correct 98.53% of detected errors in collective taxpayers with respect to LicTradNum attribute (Tax ID); 56.67% of addresses with errors in ZipCode attribute (Postal Code) and 99.65% of tuples that contain values in IntrntSite attribute, as was being used for a different purpose from that defined by the ERP, and these values were migrated to E_Mail attribute for further processing. They were also detected and eliminated 323 tuples of entities that were duplicated.

A decisão sobre implementar ou não um ERP (Sistema de Integrado de Gestão), conforme constatado na literatura consultada, não é apenas uma questão de tecnologia, mas fundamentalmente uma questão de estratégia; isso porque sua implementação demanda profundas mudanças na organização. De acordo com os resultados de algumas pesquisas já publicadas, especificamente na área de Contabilidade das organizações, a implementação do ERP provoca mudanças. Diante disso, esta pesquisa foi realizada com o objetivo de compreender e descrever a influência da implantação do ERP nos aspectos organizacionais da área de Contabilidade das empresas, mais precisamente no que se refere às mudanças na estrutura organizacional, às atividades desenvolvidas e aos conhecimentos e habilidades exigidos para a execução das atividades. Em atenção aos propósitos da pesquisa, o trabalho foi construído por meio de uma abordagem metodológica empírico-analítica com a condução de Estudos de Casos nas empresas do Estado do Paraná. Para tanto, foram analisados dois casos referentes a empresas que implementaram o ERP R/3 do fornecedor SAP. A análise dos dados indica que a implementação do ERP provoca, na área de Contabilidade das empresas, alterações na estrutura organizacional, nas atividades e nos conhecimentos e habilidades. As alterações verificadas na estrutura organizacional referem-se ao design organizacional, à estrutura de cargos e ao quadro de funcionários. Quanto às atividades, as alterações estão relacionadas ao tipo de atividade desenvolvida na área (inclusão ou exclusão) e à forma de desenvolvê-las. Com relação aos conhecimentos e habilidades, as alterações dizem respeito aos conhecimentos gerais, técnicos, habilidades intelectuais, interpessoais e de comunicação. Porém, depreende-se da análise dos dados, que a implementação de um ERP influencia mais diretamente as atividades e, como conseqüência, a estrutura organizacional e os conhecimentos e habilidades sofrem reflexos e precisam ser ajustados, ou seja, a intensidade das alterações na estrutura organizacional e nos conhecimentos e habilidades está relacionada à profundidade das mudanças ocorridas nas atividades. Todavia, embora o ERP tenha potencial para alterar as atividades, as mudanças variam de empresa para empresa, pois a implementação do ERP, por si, não promove sempre as mesmas mudanças; a natureza e a profundidade das mudanças dependem das decisões tomadas pelos responsáveis pela empresa e pela equipe de projeto, durante a fase de implementação do ERP e também posteriormente, quando o sistema já está sendo utilizado.<br>According to literature in the area, the decision about whether or not to implement ERP (Enterprise Resource Planning) is not a matter of technology alone, but rather, a matter of strategy, since its implementation requires deep changes in the organization. Still according to research already published, this implementation generates deep changes in the area of accounting of organizations as well. Due to this fact, this research was carried out aiming at understanding and describing the influence of the implementation of ERP on the organizational aspects in the area of accounting of enterprises, particularly in what concerns the changes in structure, activities developed, besides knowledge and abilities required for the carrying out of tasks. Seeking to achieve the purpose of this research, the procedures followed an empirical analytical methodological approach as a guideline to Case Studies carried out in enterprises in the State of Paraná. The analysis took into account two cases of enterprises that implemented ERP R/3 by SAP (supplier of software solutions for enterprises). The analysis of data shows that the implementation of ERP gives rise to changes not only in the organizational structure but also in activities and in knowledge and abilities within the accounting area of enterprises. The changes found within the organizational structure allude to organizational design, job designs and personnel. As far as activities go, changes are related to the kind of activity performed in the area (inclusion or exclusion), and to the way of performing them. Concerning knowledge and abilities, changes regard general and technical knowledge, and intellectual, interpersonal and communicative abilities. Nevertheless, the analysis of data leads to the understanding of the fact that ERP implementation acts more directly upon activities; thus, both the organizational structure and knowledge and abilities are affected as well, and need adjustments; that is to say, the intensity of changes operating on the organizational structure and on knowledge and abilities is related to the depth of the changes that have an effect on the activities. However, although ERP has the potential to alter activities, changes vary among enterprises, since the implementation itself does not always promote the same changes; both nature and depth of changes depend on decisions made by those responsible for the business and by the group in charge of the project, and not only during but also after ERP implementation, when the system is already in action.

This thesis investigates several aspects of visuo-spatial processing from a clinical, electrophysiological and neurofunctional perspective, with the aim of enriching our understanding of neurological syndromes that affect such fundamental perceptual-cognitive skill. A common thread is the use of cognitive load as a mean to study spatial awareness deficits following brain stroke. We show that increased task demands uncovers pathological spatial asymmetries both in right and left hemisphere damaged patients that performed at ceiling in standard paper-and-pencil tests. Although visuo-spatial deficits are commonly considered infrequent after left hemisphere lesions, the comparison between the two clinical populations showed that multitasking reveals patterns of neglect and extinction regardless of the affected hemisphere. A similar multitasking paradigm was then administered to young healthy participants in order to study the electrophysiological signatures of spatial monitoring, examining correct and erroneous processing of peripheral visual stimuli. Task difficulty was increased compared to the clinical version in order to obtain a consistent number of missed targets, thereby simulating patients’ performance. Our results support the hypothesis that processing of visual information under multitasking is regulated by a threshold criterion: the target is successfully detected only when the electrophysiological activity reaches a critical amplitude. Finally, we conducted a resting state electroencephalographic (EEG) study in order to correlate patterns of spontaneous brain activity with neuropsychological scores and multitasking costs indices. This investigation builds on the hypothesis that cognition is not only associated with the specialization of brain regions, but also with the large-scale organization of functionally connected networks. A state-of-art methodology was used to reconstruct 14 brain networks, previously detected in fMRI studies, from electrophysiological signals in chronic stroke patients. The integration of critical clusters within each network was then examined, exploring also its correlation with behavioural measures and the contribution of specific frequency bands. Overall, this empirical work provides an original contribution to the study of the mechanisms underlying brain organization after unilateral damage and the consequent implications for cognitive performance.<br>Questo lavoro di tesi indaga diversi aspetti relativi all’elaborazione visuo-spaziale da un punto di vista clinico, elettrofisiologico e neurofunzionale, al fine di contribuire allo studio dei disturbi neurologici che comportano deficit a livello percettivo. Il filo conduttore è stato l’utilizzo del carico cognitivo per studiare deficit di consapevolezza spaziale che possono emergere a seguito di un ictus cerebrale. Abbiamo mostrato come l’aumento della difficoltà di un compito sia in grado di rilevare asimmetrie spaziali patologiche in pazienti con lesioni cerebrali all’emisfero destro o sinistro che avevano una prestazione nella norma ai classici test neuropsicologici “carta e matita”. Sebbene i disturbi visuo-spaziali siano ritenuti infrequenti a seguito di lesioni emisferiche sinistre, sorprendentemente il confronto di queste due popolazioni cliniche mette in luce l’efficacia del multitasking nell’individuare pattern di negligenza ed estinzione indipendentemente dal lato della lesione. Una versione modificata del nostro paradigma di multitasking è stata inoltre somministrata ad un gruppo di giovani partecipanti sani al fine di studiare i correlati elettrofisiologici del monitoraggio spaziale, confrontando l’elaborazione corretta ed incorretta di stimoli apparsi nella periferia del campo visivo. La difficoltà del compito è stata aumentata rispetto alla versione clinica al fine di ottenere un consistente numero di stimoli non individuati e dunque di simulare la prestazione di pazienti neurologici. I nostri risultati supportano l’ipotesi che in condizione di multitasking l’elaborazione di informazioni visive sia regolata da un criterio di soglia. Nello specifico, la corretta percezione di uno stimolo è determinata dal raggiungimento di un’ampiezza critica dell’attività corticale. Infine, abbiamo condotto uno studio in resting state al fine di studiare la correlazione tra attività cerebrale spontanea e prestazione comportamentale, misurata attraverso classici indici neuropsicologici ed indici di costo al multitasking. Questo studio prende in considerazione l’ipotesi che la cognizione non sia associata soltanto alla specializzazione delle regioni cerebrali, ma anche all’organizzazione su larga scala di reti neuronali funzionalmente connesse. Attraverso l’utilizzo di un metodo di analisi allo stato dell’arte, 14 reti cerebrali, precedentemente studiate con tecniche di risonanza magnetica funzionale, sono state estratte dal segnale elettroencefalografico in un gruppo di pazienti con esiti di ictus in fase cronica. Inoltre, è stata analizzata l’integrazione di particolari cluster all’interno di ciascuna rete, indagando anche la relativa correlazione con indici comportamentali ed il contributo di specifiche bande di frequenza. In sintesi, questo lavoro empirico offre un contributo originale allo studio dei meccanismi sottostanti l’organizzazione cerebrale a seguito di ictus e delle relative ripercussioni sulla prestazione cognitiva.

Aggression and violence are social behaviors that exact a significant toll on human societies. Individuals with aggressive tendencies display deficits in effortful control, particularly in affectively charged situations. However, not all individuals with poor effortful control are aggressive. This study uses event-related potentials (ERPs) to decompose the chronology of cognitive functions underlying the link between effortful control and aggression. Specifically, this study investigates which ERPs moderate the effortful control - aggression association. We examined three successive ERP components (P2, N2 and P3) for stimuli that required effortful control. Results indicated that N2 activation, but not P2 or P3 activation, moderated the relationship between effortful control and aggression. These effects were present in negative and neutral contexts. This moderating effect was consistent with previous studies linking neural processing efficiency with reduced activation during cognitive control tasks. Our results suggest that efficient cognitive processing moderates the association between effortful control and aggression.

Recognition memory is thought to rely upon both recollection and familiarity. When people recall an episode from the past it is generally considered to reflect the memory process of recollection. Therefore, if people can successfully recall an item, they should be able to recognize it. However, in cued recall paradigms of memory research, participants sometimes correctly recall a studied target word in the presence of a strong semantic cue but then fail to recognize that word as actually having been studied. This paradox and underlying cognitive processes have been minimally studied by scientists, leaving this phenomenon poorly understood. Extant research has investigated some of the conditions necessary to produce these conditions but not the underlying neural correlates that drive them. The present study builds upon earlier studies using Electroencephalogram (EEG) to investigate the neural processes that underlie recognition failures of successfully recalled words. In the present experiment, participants studied words one at a time, and then later were asked to verbally recall these previously studied words as cued by their semantic associates. Following the participant’s verbal response, their recognition memory was tested for the recalled word. The current study aimed to use physiological measures (EEG) to investigate the explicit and implicit cognitive processes that may be involved in the recognition failure of recalled words. The data indicate that successfully recalled words that are recognized are driven by recollection at recall and a combination of recollection and familiarity at recognition, whereas successfully recalled words that are not recognized are instead driven by semantic priming at recall and at recognition, are driven by negative-going ERP effects reflecting implicit processes such as repetition fluency.

Taking decisions that are of advantage is an important survival skill. Classical economic models posit that people should try to maximize their gains and reduce losses, suggesting an idea of a perfectly rational man (Homo Economicus). Practically, people usually behave in manner that is very far from rationality. Employing neuroscience methods, the present thesis will describe a series of experiments that highlights as aspects not strictly related to payoffs affect decision-making. Experiment 1 studied brain activity (with ERPs) during gambling task, showing as decisions’ outcomes are assessed very early (within 250 ms) in terms of predictability and as this assessment is crucial for following decisions. Experiment 2 also employed ERPs, measuring risk-taking across different contexts. Results showed as P300 reflected changes in risk attitude as well as personal differences. Experiment 3 investigated decision making within social context in which people usually shows irrational behaviour. Brain activity show the involvement of theory of mind in this kind of decisions, suggesting that apparently irrational behaviour can be logic in the light of social interaction. Experiment 4 employed fMRI to study economic decision-making in social context, showing as monetary offers are perceived as social communications rather than mere economic divisions. Taken together these studies tried to narrow the gap between formal theory and real economic choice behaviour.<br>Prendere decisioni vantaggiose è un’ importante abilità. I modelli economici classici sostengono che le persone dovrebbero provare a massimizzare i loro guadagni e a ridurre le perdite, suggerendo un’idea di uomo perfettamente razionale (Homo Economicus). In pratica, le persone si comportano in maniera molto distante dalla razionalità. Usando i metodi delle neuroscienze, la presente tesi descriverà una serie di esperimenti che mettono in luce come aspetti non strettamente legati alla ricompensa monetaria influenzano le decisioni. L’esperimento 1 ha studiato l’attività cerebrale (con gli ERPs) durante un gioco rischioso, mostrando come gli esiti delle decisioni vengano valutati molto presto ( entro 250 msec) in termini di predicibilità e come questa valutazione sia cruciale per le decisioni successive. L’esperimento 2 impiega ancora gli ERPs, misurando la propensione al rischio attraverso i diversi contesti. I risultati hanno mostrato come la P300 rifletta i cambiamenti di propensione al rischio e le differenze personali. L’esperimento 3 ha indagato la presa di decisione in contesti sociali in cui le persone si comportano di solito in maniera irrazionale. L’attività cerebrale mostra un coinvolgimento delle teorie della mente in questo tipo di decisioni, suggerendo che un comportamento apparentemente irrazionale può essere logico alla luce dell’interazione sociale. L’esperimento 4 usa la fMRI per studiare le decisioni economiche in contesti sociali, mostrando come le offerte monetarie siano percepite come comunicazioni sociali piuttosto che come mere suddivisioni economiche. In generale, questi studi cercano di ridurre la distanza fra teorie formali e comportamento di scelta reale.

xv, 169 p. ; ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.<br>Improvements in neuroimaging techniques have made it possible to answer questions regarding the neural organization for the processing of syntax in normal participants. In this series of experiments we examined the effects of linguistic proficiency and age of second language acquisition on neural organization for syntactic processing. We examined these factors using two complementary methodologies: event-related potentials (ERPs), which affords a temporal resolution on the order of milliseconds, and functional magnetic resonance imaging (fMRI), with spatial resolution on the order of millimeters. In order to compare results across methodologies, we used an auditory syntactic violation paradigm with similar experimental parameters in each methodology. In Chapter II we examined neural organization for syntactic processing using ERPs in monolingual native speakers of higher and lower proficiency and found that violations elicited an early onset (100 ms) anterior negativity (EOAN) followed by a later positivity (P600) in all participants. Compared to lower proficiency participants, higher proficiency participants showed an EOAN that was more focal spatially and temporally, and showed a larger P600. These results were supported by a correlational analysis of a larger group of monolingual native speakers with a wide range of proficiency scores. This analysis also found a relationship between childhood socioeconomic status and the recruitment of the EOAN over left hemisphere sites, raising the hypothesis that effects of childhood experience may endure into adulthood. In Chapter III we examined the effects of age of acquisition on syntactic processing by recruiting a group of late learners of English who were matched for proficiency with a group of monolingual native speakers from Chapter II. While in native speakers violations elicited a robust EOAN, this effect was absent in the late learner group, suggesting that early language exposure is important for the recruitment of resources reflected in this effect and independently of proficiency. In Chapter IV we gathered ERP and fMRI data from monolingual native speakers and found proficiency differences in the recruitment for syntactic processing of left inferior frontal and posterior regions. We linked proficiency-related modulations in the different ERP syntactic effects to specific fMRI activations indexing syntactic processing.<br>Adviser: Helen J. Neville

Esta dissertação tem como objetivo principal, demonstrar como são escolhidos, implantados e utilizados os sistemas ERP pelas pequenas e médias empresas da cadeia de suprimentos das indústrias de autopeças de uma cidade do interior de São Paulo; corresponde a uma pesquisa de caráter quantitativo e qualitativo combinados sobre Sistemas ERP implantados ou em fase de implantação; foi realizado um amplo levantamento bibliográfico que aborda vários assuntos relacionados aos sistemas ERP, 24 empresas sindicalizadas foram visitadas, para a aplicação de um questionário que permitiu identificar várias características dos sistemas ERP nestas empresas, como conclusão do trabalho, observações foram feitas em relação à implantação, principalmente quanto a diferente realidade das industrias de pequeno e médio porte em relação a literatura encontrada, aos elementos tecnológicos, humanos, gerenciais e gerais do Sistema ERP, contemplando também sugestões para os próximos trabalhos na área como por exemplo, a evolução da literatura sobre ERP em três vertentes: Ciclo de vida dos sistemas ERP; papel a ser desempenhado dentro do contexto empresarial e a divisão da literatura em: Implantação, estrutura e assuntos complementares de sistemas ERP e modelos de sistemas ERP. Como a pesquisa segue a linha de raciocínio de outras pesquisa que não consideram o seguimento da organização, pode-se utilizar os resultados para outros seguimentos apenas garantindo que as empresas estudadas sejam de pequeno e médio porte.<br>The main goal of this dissertation, is to demonstrate how are chosen, implanted and used the ERP systems for the small and medium companies of the supply chain auto parts industry from a city outside region of São Paulo; corresponding a combination of qualitative and quantitative research about ERP System implanted or in process of implementation; it was used a large bibliography that contain various topics related to ERP systems, 24 companies that are members of union were visited, to apply a questionnaire, allowing the identification of several characteristics of ERP systems in those companies, as the conclusion of this dissertation, observations were made related to the implementation, mainly about the difference of the reality in the small and medium companies related with the literature found, with the technological elements, human, management and general of the ERP System, also containing suggestions for following researches, as an example, the evolution of the ERP literature in three main subjects: Lifecycle of ERP Systems, the function to be developed in business context and the division of the literature in: Implementation, structure and complementary subjects of ERP Systems and models of ERP Systems. As the research follow the same direction of other researches, that do not consider the segment of the organization, it is allowed to use the results to other segments, only with the guarantee that the companies are small or medium size.

Psychopathy is traditionally defined as a personality disorder characterized by two main factors: “Emotional Detachment” and “Antisocial Behavior”. With respect to the first factor, classic diagnostic criteria for psychopathy include lack of empathy, emotional callousness, lack of guilt or remorse, and egocentricity. With regard to the second factor, psychopathic individuals show an impulsive behavior without regard for consequences, an absence of long-term goals, perseverative responses, irresponsibility, antisocial and criminal behavior (Hare, 1993). Cleckley (The Mask of Sanity, 1941) defined two types of psychopaths: “Successful” and “Unsuccessful”. “Unsuccessful” psychopaths present with the typical profile of the disorder, entailing emotional detachment and also antisocial behavior. They manifest violent and criminal behavior and serve several terms of imprisonment. “Successful” psychopaths present with emotional detachment, but a high IQ, and familiar and social favorable environment keeps them away from troubles. Nevertheless, they are egocentric, conspirers, and callous, and their behavior, even if not criminal or illegal, typically violates ethical and moral norms. In past years, several studies have been conducted in forensic facilities and jails, on “unsuccessful” criminal psychopaths, thus producing interesting results, but poorly applicable to normal population. It’s important to extend these studies to “Successful” psychopaths in the community, and to explore analogies and discontinuities between these two categories. Also, research in detention institutes is often focused on male psychopaths, due to the predominant presence of this gender into jail, hence the importance to study female psychopathy and to analyze similarities and differences between the two genders in the characterization of the disorder. The main goal of the present project was to investigate the emotional regulation in women with high empathic or “successful” psychopathic traits and empathic and psychopathic traits selected from the healthy community. In the first study, we analyzed the influence of empathy on subjective evaluation of emotional pictures and emotional psychophysiological responses (startle reflex, ERPs) in healthy women. Results showed how different levels of empathy had an influence on evaluation of valence and arousal elicited by emotional stimuli. Participants with low empathy levels rated negative pictures as more pleasant, and both positive and negative pictures as less arousing than the group with high empathy levels, indicating a reduced perceived bodily activation. With regards to startle reflex responses and event-related potentials, no differences between the two groups were found. In the second study, we analyzed individual differences in subjective evaluations and affective psychophysiological responses (startle reflex, ERPs) elicited by emotional pictures, in women with low and high baseline startle responses. The two groups (Low Responders vs. High Responders) did not differ in their subjective evaluation of the pictures, but they differed in their affective modulation of the startle reflex: while the High Responders showed an inhibition of the reflex in response to pleasant stimuli, and a potentiation of the reflex in response to unpleasant stimuli, the Low Responders did not show an affective modulation of the reflex in response to any emotional stimulus. Low Responders also manifested reduced cortical responses while viewing emotional stimuli, compared to High Responders. The main goal of the third study was to analyze the capability of Decision-making and cortical responses measured by ERPs in women with high psychopathic traits and a control group through the Iowa Gambling Task. Participants with high psychopathic traits showed perseverative responses during the performance, hyposensitivity to punishment, and hypersensitivity to rewards, compared to the control group. The forth study aimed at examining the associations between the triarchic conceptualization of psychopathy (measured by the three factors: boldness, meanness, disinhibition), as measured by the Triarchic Psychopathy Measure, and the Narcissistic construct, as measured by the Narcissistic Personality Inventory, in undergraduate students. Several facets of narcissism were found to be related to distinctive configurations of psychopathic traits. The Narcissistic Personality Inventory revealed to capture both the grandiose and vulnerable aspects of narcissism. In conclusion, the first three studies evidenced how women with low empathy and high psychopathic traits show impairment in emotional regulation and in decision-making capabilities. “Successful” psychopaths can cause relevant physical and moral damages to individuals and society. The fourth study provided a better understanding of the relationship between psychopathy and narcissism.<br>La psicopatia viene tradizionalmente definita come un disturbo di personalità caratterizzato da due fattori principali: “Distacco Emotivo” e “Comportamento Antisociale”. Per quanto riguarda il primo fattore, i classici criteri diagnostici per la psicopatia includono mancanza di empatia, affettività superficiale, mancanza di senso di colpa o rimorso, ed egocentrismo. Per quanto riguarda il secondo fattore, individui con psicopatia presentano comportamento impulsivo senza riguardo per le conseguenze delle proprie azioni ed un’assenza di obiettivi a lungo termine, risposte perseverative, irresponsabilità, e comportamento antisociale e criminale (Hare, 1993). Cleckley (The Mask of Sanity, 1941) ha definito due categorie di psicopatici: “Successful” ed “Unsuccessful”. Gli psicopatici “Unsuccessful” manifestano il profilo tipico del disturbo, con distacco emotivo e devianza sociale. Presentano comportamenti violenti e criminali e scontano ripetute pene nelle carceri. Gli psicopatici “Successful” manifestano distacco emotivo, ma grazie ad un elevato quoziente intellettivo, e all’ambiente familiare e sociale, riescono a mantenere una parvenza di normalità e a tenersi lontani dai guai. Sono egocentrici, cospiratori, superficiali, e il loro comportamento, seppur non criminale o illegale, viola spesso le norme etiche e morali convenzionali. Negli scorsi anni sono stati condotti diversi studi nelle carceri e in ambienti giudiziari, con psicopatici “Unsuccessful” e criminali, portando ad un bias ambientale e a risultati scarsamente applicabili alla popolazione normale. È importante estendere questi studi a psicopatici “Successful” nelle comunità, in modo tale da poter esplorare analogie e differenze tra queste due categorie di psicopatici. Inoltre, la ricerca nelle carceri si è per lo più focalizzata su psicopatici maschi, a causa della prevalente presenza di persone di sesso maschile nelle carceri, da qui l’importanza di studiare la psicopatia al femminile e di approfondire l’eventuale presenza di differenze nella manifestazione della sindrome tra i due generi. Obiettivo principale del presente lavoro di tesi è stato quello di investigare la relazione tra regolazione emozionale e tratti empatici e psicopatici in donne “Successful” nella comunità. Nel primo studio è stata analizzata l’influenza di diversi livelli di empatia sulla valutazione soggettiva di immagini emozionali e sulle risposte emozionali psicofisiologiche (riflesso di startle, ERPs). I risultati hanno mostrato come differenti livelli di empatia avessero un’influenza sulla valutazione soggettiva di valenza ed arousal elicitati da immagini emozionali. Le partecipanti con bassi livelli di empatia valutavano le immagini negative come più piacevoli, e sia le immagini positive che quelle negative come meno attivanti, rispetto al gruppo con alti livelli di empatia, ad indicare una ridotta percepita attivazione corporea di fronte a stimoli emotigeni. Non sono state trovate differenze tra i due gruppi nelle risposte emozionali psicofisiologiche (startle reflex, ERPs). Nel secondo studio sono state analizzate differenze individuali nella valutazione soggettiva e nelle risposte affettive psicofisiologiche (startle reflex, ERPs) elicitate da immagini emozionali, in donne con bassi ed alti livelli di reattività di startle di base. I due gruppi (Low Responders vs. High Responders) non differivano nella loro valutazione soggettiva delle immagini, ma differivano nella modulazione affettiva del riflesso di startle: mentre le High Responders manifestavano un’inibizione del riflesso in risposta a stimoli piacevoli, ed un potenziamento della risposta in risposta a stimoli spiacevoli, le Low Responders non mostravano alcuna modulazione affettiva del riflesso in risposta ai vari stimoli emozionali. Inoltre, le Low Responders manifestavano ridotte risposte corticali durante la visione degli stimoli emozionali, rispetto alle High Responders. Obiettivo principale del terzo studio era quello di analizzare le capacità di decision-making e le risposte corticale misurate tramite ERPs in donne con elevati tratti di psicopatia ed un gruppo di controllo, tramite l’utilizzo dello Iowa Gambling Task. Le donne con elevati tratti di psicopatia manifestavano risposte perseverative durante il compito, una ridotta sensibilità alle punizioni, ed un’elevata sensibilità alle ricompense, rispetto al gruppo di controllo. Il quarto studio mirava ad esaminare l’associazione tra la concettualizzazione triarchica della psicopatia (secondo la quale la sindrome può essere analizzata secondo i tre concetti di boldness, meanness, e disinhibition) , misurata tramite la Triarchic Psychopathy Measure, ed il construtto narcisistico, misurato tramite il Narcissistic Personality Inventory, in studenti universitari. Diversi tratti narcisistici hanno mostrato di essere associati a specifiche configurazioni di tratti psicopatici. Il Narcissistic Personality Inventory ha mostrato di catturare sia gli aspetti “grandiosi” sia quelli “vulnerabili” del disturbo. In conclusione, i primi tre studi hanno evidenziato come donne con bassi livelli di empatia ed elevati tratti di psicopatia mostrino deficit nella regolazione emozionale e nel decision-making. Tali deficit possono avere rilevanti conseguenze negative, sia fisiche che morali, sugli individui e sulla società nel suo insieme. Il quarto studio ha fornito una migliore comprensione della relazione tra psicopatia e narcisismo.