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1
Debener, Stefan. "Individuelle Unterschiede in der frontalen EEG-Alphaasymmetrie: Emotionalität und intraindividuelle Veränderungen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2001. http://nbn-resolving.de/urn:nbn:de:swb:14-1000888669859-38345.
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Petzold, Antje. "Lateralized Head Turning Bias in Humans – Cues to the Development of Human Cerebral Asymmetries." Bachelor's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-24971.
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The origin and development of human cerebral asymmetries is yet a debated issue. One prominent manifestation of cerebral asymmetry is handedness with humans showing a dextral population bias. Handedness in humans is not fully established before the age of six. However, head turning preference in newborns is thought to be an important factor in the development of later handedness. If this head turning preference did not disappear completely during development but would prevail into adulthood it might, thus, be associated with handedness. Therefore, this study aimed to assess head turning preference in adults and to relate a possibly emerging bias to handedness.
Forty-two adults (6 females, aged 23- 63, mean age = 35) participated in the study. Head turning preference was assessed by means of a move during Ju Jutsu martial arts training, which requires the trainee to move the head to either left or right. The direction of head movement is not specified for this move, leaving the choice to the trainee. Handedness was measured by the Edinburgh Handedness Inventory.
Results did not reveal a profound head turning bias in adults. Contrary to the dextral bias in handedness, in this study a leftward bias in head turning emerged from those participants who showed a head turning preference. Head turning bias did not depend on handedness.
The finding of a nearly absent and predominantly leftward head turning bias in this sample is discussed in the context of the Ju Jutsu task, training experience and trainer bias. It is concluded that the Ju Jutsu move is not a sufficient task to assess head turning preference in humans. Thus, to further illuminate the relation between head turning preference and handedness, studies are needed which assess head turning preference in adults in an un-trainable and unbiased situation.
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Hausmann, Markus. "Steroidmodulation funktioneller cerebraler Asymmetrien." [S.l.] : [s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=960030581.
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Nicholls, Michael E. R. "Cerebral asymmetries for temporal resolution." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309007.
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Elias, Lorin J. "Cerebral asymmetries in processing language and time." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq38236.pdf.
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Kingery, Lisle R. "The Psychological Correlates of Asymmetric Cerebral Activation." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/KingeryLR2003.pdf.
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Broks, Paul. "Hemisphere asymmetries in schizophrenia." Thesis, University of Oxford, 1987. http://ora.ox.ac.uk/objects/uuid:d724a3b5-fce5-4ae0-9db7-a583b625754a.
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Previous research into everyday conception of personal relationships has been sparse and fragmented, and the various specialisms fail to deal with the broader issue of interpersonal understanding. Following review of the research and theoretical background, with particular reference to changing paradigms, a holistic approach is proposed for an exploration linking the content of explanation and reflection about relationships with the incidence of conceptualising. The methodology, employing content analysis, illustrative studies and a musical analogue, is outlined. Initially focusing on verbalised conception in the form of accounts, a procedure of 'simulated correspondence with a confidant' was employed to facilitate unrestricted disclosures in general descriptions of relationships. Three coding schemes were devised for content analysis of accounts (and for independent use in subsequent research). These pertained to: (1) specific concepts and themes; (2) explanation of interpersonal effect and significance; and (3) intersubjectivity in accounts. Overall indications from the content analyses are that accounts are characterised by superficiality of detail and insight, and concentrate more on basic viability, and on social and visible aspects of personal relationships than on intimate and psychological aspects. The limitations of content analysis, and the deficiencies disclosed, suggest attention should be given to omission in content as much as inclusion, and also to the prior issues of motivation and the extent of relationship "mindfulness". A musical analogy (with particular reference to representation, knowledge and appreciation) is employed to advance the exploration beyond the linguistic aspects of conception to a more general model of relationship awareness. A second set of studies turn to (1) the frequency and occasioning of reflection on relationships; (2) reappraisal over time; (3) interest in relationships compared with other subjects of general interest; and (4) factors which disincline conscious relationship deliberation and analysis. There are indications throughout of a sex difference, with men as less reflective, less inclined to participate in providing accounts, and less interested in personal relationships. Disincentives are suggested, and a theory of 'relationship mindlessness' is discussed, connecting impoverishment of content and incidence with the late emergence of 'personal relationships' as a subject of formal scholarly enquiry in psychology. It is proposed that such mindlessness, and associated disincentives, are implicated in relationship problems, and that extension of relationship education, knowledge and interest are indicated. The practicalities and possible form of learning about relationships and consciousness-raising were explored in a trial relationship understanding course. Counter-indicat ions for such consciousness-raising were evaluated by analogy with music appreciation.
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Clark, Gina M. "Cerebral asymmetry in adolescent onset psychosis." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442813.
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Dann, P. L. "Cerebral asymmetry and individual differences in reading." Thesis, University of Plymouth, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383783.
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LaMendola, Nicholas Paul. "Cerebral asymmetries for radial-maze foraging in the rat." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/290146.
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Rats were trained to locate food rewards in a subset of maze arms over fifty trials in one of two radial mazes. One group was trained on this foraging task in a walled radial maze used by LaMendola & Bever (1997), and the other group was trained in a more conventional runway style radial maze. Experiment 1 demonstrated both quantitative and qualitative differences in foraging behavior amongst untreated control rats. Experiment 2 demonstrated different left-right asymmetries for learning in each maze. Asymmetries were elicited by locally anesthetizing the same side of a rat's whiskers throughout training. When rats were trained on the runway maze, they made fewer errors when their left whiskers were intact. When trained on the walled maze, rats made fewer errors when their right whiskers were intact. Qualitative differences in arm choice behavior accompanied the asymmetry in the walled maze only. Experiment 3 demonstrated that rats were affected in different ways to rotation of either intramaze or extramaze visual cues in either maze. Arm choice accuracy was adversely affected when the rewards were rotated with respect to the extramaze cues in the runway maze, and intramaze cues in the walled maze. Left-right differences amongst whisker treated rats emerged only in the walled maze. Cumulatively, the results suggest that rats use different foraging strategies to solve the same task in two different maze conditions. The strategy associated with each maze elicited unique contributions from each hemisphere. Left-right asymmetries emerged for the performance measures in the runway maze, and for both performance and arm choice measures in the walled maze. This suggested that the walled maze required more involvement of the cerebral hemispheres in the processing of the task. Each hemisphere solved the task in qualitatively different ways. The LH used an abstract or allocentric spatial strategy to represent the locations of rewards across trials, while the RH used an egocentric strategy to keep track of the rat's movement through the maze within a trial. No such specialization was found between hemispheres in the runway maze because of the dependence on the hippocampus for cognitive processing.
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Johnstone, Leah T. "Hemispheric asymmetries : behavioural, kinematic, and electrophysiological predictors of cerebral organisation." Thesis, Bangor University, 2016. https://research.bangor.ac.uk/portal/en/theses/hemispheric-asymmetries-behavioural-kinematic-and-electrophysiological-predictors-of-cerebral-organisation(1fcdf175-059d-4647-8577-8044e365e14c).html.
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Our best estimates suggest that ~95% of dextrals and ~70% of adextrals have left hemisphere language dominance. Currently the only way to determine language lateralisation is to use invasive hemispheric anaesthetising procedures, or expensive functional neuroimaging methods. This lack of identification has led to adextrals being studied as an ‘atypical’ group in terms of functional lateralisation, despite the vast majority of them sharing the same brain organisation as dextral subjects. Therefore research into brain asymmetries or atypical dominance could progress much more quickly if a more successful predictor (or combination of predictors) of cerebral lateralisation than handedness were available. This body of work investigates the potential usefulness of behavioural, kinematic, and electrophysiological measures to predict cerebral asymmetries. These data are discussed in the first three experimental chapters, and the fourth chapter contains a neuroimaging project. In this final study language, face, and body processing asymmetries are identified in dextral and adextral participants who had taken part in the initial lab-based tests. The results from this thesis suggest that a consonant-vowel dichotic listening task, as well as strength of left-sidedness, may increase successful identification of ‘atypical’ language dominance beyond the 15% success of left-handed writing. Additionally, ear advantage on a further listening paradigm, the Octave illusion, differentiates between dextral and adextral subjects in a way that appears related to language lateralisation. Kinematic measures may be related to brain organisation, but the relationship is less clear than in the more successful behavioural lab tests. Finally, asymmetries in electrophysiological components are a poor predictor of functional lateralisation. This thesis advocates against the exclusive use of measures of central tendency, promoting alternative proportional and individual level analyses. This assessment has implications for laterality researchers using any methodology from behavioural neuropsychology to functional neuroimaging.
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Kilian, Annette. "Funktionelle cerebrale Asymmetrien visueller Prozesse und numerische Fähigkeiten beim Grossen Tümmler (Tursiops truncatus)." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972544941.
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Najt, Pablo. "Functional cerebral asymmetries of emotional processes in the healthy and bipolar brain." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/6949/.
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The perception and processing of emotions are of primary importance for social interaction, which confers faculties such as inferring what another person’s feels. Brain organisation of emotion perception has shown to primarily involve right hemisphere functioning. However, the brain may be functionally organised according to fundamental aspects of emotion such as valence, rather than involving processing of emotions in general. It should be noted, however, that emotion perception is not merely a perceptual process consisting in the input of emotional information, but also involves one’s emotional response. Therefore, the functional brain organisation of emotional processing may also be influenced by emotional experience. An experimental model for testing functional cerebral asymmetries (FCAs) of valenced emotional experience is uniquely found in bipolar disorder (BD) involving impaired ability to regulate emotions and eventually leading to depressive or manic episodes. Previous models have only explained hemispheric asymmetries for manic and depressive mood episodes, but not for BD euthymia. The present thesis sought to investigate FCAs in emotional processing in two major ways. First, FCAs underlying facial emotion perception under normal functioning was examined in healthy controls. Secondly, functional brain organisation in emotional processing was further investigated by assessing FCAs in the bipolarity continuum, used as an experimental model for studying the processing of emotions. In contrast with previous asymmetry models, results suggested a right hemisphere involvement in emotional experience regardless of valence. Atypical FCAs were found in euthymic BD patients reflecting inherent aspects of BD functional brain organisation that are free of symptomatic influence. Also, BD patients exhibited atypical connectivity in a default amygdala network particularly affecting the right hemisphere, suggesting intrinsic mechanisms associated with internal emotional states. Last, BD patients were associated with a reduced right hemisphere specialisation in visuospatial attention, therefore suggesting that right hemisphere dysfunction can also affect non-emotional processes. Taken together, the findings emphasize a BD continuum model relying on euthymia as a bridging state between usual mood and acute mood phases.
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Jernberg, Grönlund Annika. "Posturala asymmetrier och smärta hos barn med cerebral pares : En populationsbaserad registerstudie." Thesis, Umeå universitet, Avdelningen för fysioterapi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-167463.
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Sammanfattning: Introduktion: Nedsatt förmåga att stabilisera kroppen leder ofta till asymmetrisk kroppshållning som ökar risken för vävnadspåverkan som kan leda till deformiteter och kontrakturer hos barn med cerebral pares (CP). Smärta är vanligt förekommande vid CP och kan komma sekundärt till kontrakturer och felställningar. Syfte: Undersöka samband mellan posturala asymmetrier i ryggliggande och smärta hos barn med cerebral pares i åldrarna 7-15 år samt kontrollera om detta påverkas av ålder, kön eller grovmotorisk funktionsnivå. Metod: Tvärsnittstudie med populationsbaserad inklusion, 3123 barn i åldrarna 7-15 år med cerebral pares (60 % pojkar) ifrån det nationella kvalitetsregistret för cerebral pares (CPUP). Postural Albility Scale (PAS) användes för att bedöma asymmetrier. Förhållandet mellan asymmetrier och smärta analyserades med univariat och multivariat logistisk regression och redovisades med oddskvot (OR). Resultat: Barn med svåra asymmetrier i ryggliggande hade signifikant ökad risk för smärta, sagitalt (p=0.001) (OR=1.85, 95 % av CI 1.29-2.65), frontalt (p=0.002) (OR=1.72, 95 % av CI 1.21-2.44) och sammanslaget frontalt och sagitalt (p≤0.001)(OR=1.99, 95 % av CI 1.52-2.62). Sambandet var oberoende av ålder, kön och grovmotorisk funktionsnivå. Barn med mycket begränsad grovmotorisk funktionsnivå var överrepreseterade bland de med svåra asymmetrier och smärta. Slutsats: Tydliga samband framkom mellan svåra asymmetrier i ryggliggande och smärta hos barn 7-15 år med CP. Barn med kraftigt nedsatt grovmotorisk förmåga var överrepresenterade i gruppen med svår asymmetri och smärta. Ett sätt att förebygga smärta kan vara att uppmärksamma asymmetrier och vidta åtgärder för att minska dess fortskridning. Svåra asymmetrier i ryggliggande bör ses som en indikation att utreda smärta hos barn med CP.
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Demakis, George J. "Functional cerebral asymmetry : a test of the selective activational model /." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-12232009-020403/.
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Chen, Jing, and 陈静. "Distinction between nonconscious and conscious vision : evidence from hemispheric asymmetry effects." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206426.
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Here we examined hemispheric differences in conscious and nonconscious perception using a masked priming paradigm. In Experiment 1, participants judged the direction of a grey target arrow (either left- or right-pointing), which was preceded by a grey prime arrow in either the left visual field (LVF)/right hemisphere (RH) or the right visual field (RVF)/left hemisphere (LH). The prime was either masked or unmasked. Participants reported unaware of the prime in the masked condition. We found a significant congruency effect (i.e., a faster response when the prime and target directions were congruent than when they were incongruent) when the prime was presented in the LVF/RH but not the RVF/LH in the masked (subliminal) condition. In contrast, in the unmasked (supraliminal) condition, the RVF prime had a stronger congruency effect than the LVF prime. In Experiment 2, a backward mask was used in all trials and the prime duration was manipulated to create subliminal and supraliminal conditions. In the subliminal condition, LVF/RH primes but not RVF/LH primes generated a congruency effect, whereas in the supraliminal condition, RVF/LH primes had a bigger congruency effect than LVF/RH primes. These qualitatively different hemispheric asymmetry effects in Experiment 1 and 2 suggest that nonconscious and conscious perception may involve different underlying mechanisms. In Experiment 3, color stimuli instead of grayscale stimuli were used. Neither the congruency effect nor the LVF/RH advantage was found in the subliminal condition, while a similar RVF/LH advantage in the congruency effect was found in the supraliminal condition. This result suggests that parvocellular input does not support the subliminal priming effect in the LVF/RH. Taking together, our results revealed a dissociation between the mechanisms underlying nonconscious and conscious processing, and this dissociation may be due to the dominant role of the magnocellular pathway in nonconscious vision.published_or_final_version
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Wilcox, Gary A. (Gary Alden). "Handedness, Perceptual and Short Term Memory Asymmetries, and Personality." Thesis, North Texas State University, 1985. https://digital.library.unt.edu/ark:/67531/metadc331119/.
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A large body of research has depicted relative arousal of the left and right cerebral hemispheres as related to utilization of particular defensive coping styles, level of anxiety, and perceptual styles. The right and left hemispheres are also presented in the literature as differing in visual-spatial and verbal-auditory short term memory abilities.
The present research studied 127 right handed undergraduates' relative performance on forward spatial and digits memory spans in relation to hemispheric lateralization and other perceptual and personality variables hypothesized in the literature to be related to hemispheric arousal.
It was hypothesized that the forward spatial and digit memory spans would display asymmetrical sensitivity to hemispheric arousal. That is, in a series of successive factor analyses, a hemispheric balance factor, a trait anxiety factor, and a short term memory factor would emerge. The three factors were hypothesized to be unrelated to each other.
During an initial group pretesting, subjects were given pencil and paper measures of handedness, trait anxiety, and several defensive coping styles. During a second individual testing, subjects were administered measures of short term memory, field independence, and a computerized presentation of geometric designs which measured the subjects ability to detect differences which occurred at either the global or analytic level (Navon task).
The factor analyses revealed only the hypothesized trait anxiety factor. The hypothesized short term memory and hemispheric balance of arousal factors did not emerge. Instead, a. defensive coping style factor and separate verbal—auditory and visual-spatial short term memory factors emerged.
Several methodological difficulties of the present study which possibly contributed to the failure of the two hypothesized factors to emerge were discussed. Several additional findings, including sex differences in hemispheric lateralization, were presented. Also, signal detection analysis revealed a pattern such that trait anxious subjects were biased toward over-reporting differences on the Navon task. Implications for further research were presented.
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Moffat, Scott Douglas. "Relations between testosterone, neuroanatomical structure and functional cerebral asymmetry in humans." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0003/NQ31089.pdf.
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Alves, Nelson Torro. ""Percepção de expressões faciais da emoção e lateralização cerebral"." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/59/59134/tde-14092005-140244/.
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Tem sido freqüentemente discutido na literatura científica o papel que desempenha cada hemisfério cerebral no processamento da informação emocional. O estudo realizado teve por objetivo investigar o padrão de dominância hemisférica para a percepção das expressões faciais de alegria, tristeza, raiva e medo. Em dois experimentos realizados foi utilizada a técnica de estudo campo visual dividido com a apresentação taquitoscópica de estímulos por 150 ms na tela de um monitor. Os estímulos foram compostos com fotografias de faces de quatro indivíduos (2H, 2M) retiradas da série Pictures of Facial Affect. Vinte e um observadores destros (9H, 12M) participaram do experimento 1. Em cada tentativa eram apresentadas duas fotografias de faces, uma à esquerda e outra à direita do ponto de fixação na tela do computador, em quatro diferentes condições: 1) face com emoção à esquerda e face neutra à direita, 2) face neutra à esquerda e face com emoção à direita, 3) face com emoção à direita e à esquerda, 4) face neutra à direita e à esquerda. Em cada tentativa, os observadores determinaram o lado em que havia sido apresentada a face que aparentava expressar mais emoção. Dezessete observadores destros (8H, 9M) participaram do experimento 2. Em cada apresentação de estímulo, uma foto de face era apresentada à direita ou à esquerda do ponto de fixação, localizado no centro da tela, e do lado oposto era apresentado um retângulo cinza. Foram elaboradas as seguintes condições de estímulo: 1) face com emoção à esquerda e retângulo cinza à direita, 2)retângulo cinza à esquerda e face com emoção à direita, 3) face neutra à esquerda e retângulo cinza à direita, 4) retângulo cinza à esquerda e face neutra à direita. Em cada tentativa, os observadores determinaram se a face apresentada aparentava ou não possuir emoção. Os tempos de reação e os erros de julgamento foram submetidos a ANOVAs para medidas repetidas. No primeiro experimento, a emoção foi em geral detectada mais rapidamente em faces apresentadas no campo visual esquerdo (p<0,01). As expressões de tristeza e raiva também foram percebidas mais rapidamente quando apresentadas no campo visual esquerdo (p<0,05). Em ambos os experimentos, as expressões de alegria e medo foram percebidas mais rapidamente e mais acuradamente que as expressões de tristeza e raiva (p<0,001). A expressão de tristeza foi detectada mais facilmente em faces femininas e a expressão de raiva em faces masculinas (p<0,05). De maneira geral, entretanto, a emoção foi detectada mais facilmente em faces femininas. Em ambos os experimentos houve diferenças entre as faces dos quatro indivíduos que representavam as expressões faciais. O hemisfério direito mostrou-se superior ao esquerdo na percepção das expressões faciais, especialmente na percepção das expressões de tristeza e raiva. A vantagem perceptiva do hemisfério direito é mais evidente para as expressões que são detectadas com maior dificuldade. A percepção de expressões faciais pode ser afetada pelo gênero da face e pelas singularidades da expressão facial individual.The role that each brain hemisphere plays in the processing of emotional information has been frequently discussed in the scientific literature. The aim of this study was to investigate the pattern of hemispheric dominance for the perception of the facial expressions of happiness, sadness, anger and fear. In two experiments the divided-visualfield technique was used with the taquitoscopic presentation of stimuli on a computer screen for 150 ms. The stimuli were composed with pictures of faces of four people (2M,2F) taken from the series Pictures of Facial Affect. Twenty one right-handed observers (9M,12F) took part in the experiment I. In each trial two pictures of faces were presented on the computer screen, one of them placed on the left side and the other one on the right side of the fixation point, in four different conditions: 1) face with emotion on the left and neutral face on the right, 2) neutral face on the left and face with emotion on the right, 3)face with emotion on the right and on the left, 4) neutral face on the right and on the left. In each trial the observers determined the side on which the face seemed to show greater emotional intensity. Seventeen right-handed observers (8M, 9F) took part in the experiment II. In each stimulus presentation, a picture of a face was presented either on the right or left side of the fixation point, placed on the center of the screen and, on the opposite side, a gray rectangle was presented. The following stimuli conditions were elaborated: 1) face with emotion on the left and gray rectangle on the right, 2) gray rectangle on the left and face with emotion on the right, 3) neutral face on the left and gray rectangle on the right, 4) gray rectangle on the left and neutral face on the right. In each trial the observers determined if the face presented had emotion or not. Time reactions and judgement errors were submitted to ANOVAs for repeated measures. In the first experiment, emotion was generally detected more quickly in faces presented on the left 10 visual field (p<0,01). The expressions of sadness and anger were also perceived more quickly when presented on the left visual field (p<0,05). In both experiments, expressions of happiness and fear were perceived more quickly and more accurately than expressions of sadness and anger (p<0,001). The expression of sadness was detected more easily in feminine faces and the expression of anger in masculine faces (p<0,05). In general, however, the emotion was detected more easily in feminine faces. In both experiments there were differences in the perception between the faces of the four individuals that represented the facial expressions. The right hemisphere showed superior to the left hemisphere in the perception of facial expressions, especially for the perception of expressions of sadness and anger. The perceptive advantage of the right hemisphere is more evident for the expressions that are detected with more difficulty. The perception of facial expressions can be affected by the gender of the face and the singularities of the individual facial expression.
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Crews, William David Jr. "Cerebral asymmetry in facial affect perception of women : neuropsychological effects of depression /." This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09052009-040440/.
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Crews, William David. "Cerebral asymmetry in facial affect perception of women: neuropsychological effects of depression." Thesis, Virginia Tech, 1992. http://hdl.handle.net/10919/44557.
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Kornisch, Myriam. "Estimates of functional cerebral hemispheric differences in monolingual and bilingual people who stutter." Thesis, University of Canterbury. Communication Disorders, 2015. http://hdl.handle.net/10092/10739.
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Purpose: The aim of this research was to examine the relationship between stuttering and bilingualism to hemispheric asymmetry for the processing and production of language.
Methods: A total of 80 native speakers of German were recruited for the study, ranging in age from 15 to 58 years. Out of those 80 participants, 40 participants were also proficient speakers of English as a second language (L2). The participants were organised into four speaker groups (20 per group) according to language ability and speech status, consisting of monolinguals who stutter (MWS), monolinguals who do not stutter (MWNS), bilinguals who stutter (BWS), and bilinguals who do not stutter (BWNS). Each of the four groups comprised 12 males and 8 females. All participants completed a battery of behavioural assessments measuring functional cerebral hemispheric asymmetry during language processing and production. The behavioural tests included (1) a dichotic listening paradigm, (2) a visual hemifield paradigm, and (3) a dual-task paradigm.
Results: Overall, the results showed no significant differences in language lateralisation between participant groups on the three behavioural tests. However group differences were identified in regard to executive functions on the visual hemifield and dual-task paradigms. Both bilingual groups showed significantly faster reaction times and fewer errors than the two monolingual groups on the visual hemifield paradigm. The bilingual groups also performed similarly on the dual-task paradigm, while the MWS group tended to show greater task disruption. No meaningful relationship was found between stuttering severity and the majority of results obtained for the test conditions. However, all four language modalities were found to correlate significantly with results obtained for the visual hemifield and dual-task paradigms, suggesting that performance on these tests increased with higher L2 proficiency.
Conclusion: Although no differences in language lateralisation were found, it appears that bilingualism had a greater influence on functional cerebral hemispheric processing than stuttering. A prevailing finding was that bilingualism seems to be able to offset deficits in executive functioning associated with stuttering. Brain reserve and cognitive reserve are thought to have a close interrelationship with the executive control system. Cognitive reserve may have been reflected in the present study, resulting in a bilingual cognitive advantage. Hence, the results of the present study lend support to previous findings implicating the benefits of bilingualism.
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Everhart, Daniel Erik Jr. "Cerebral Regulation of Cardiovascular Functioning and Fluency among Anxious and Nonanxious Men." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30497.
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This experiment investigated lateralized hemispheric regulation of the autonomic nervous system (ANS) among high anxious and nonanxious university undergraduate men using a novel laboratory paradigm. Specifically, this three phase paradigm entailed the administration of a verbal fluency (left frontal) and nonverbal fluency (right frontal) task with or without the threat of a painful stimulus (cold pressor) to high anxious and nonanxious participants. Thus, the cerebrums are hypothesized to be engaged in a dual-task experience requiring the regulation of the ANS and concurrent performance on the verbal or the nonverbal fluency measure. Given the literature which supports relative right hemisphere activation among anxious individuals, it was hypothesized that high anxious men would (1) demonstrate greater physiological arousal to the cold pressor, (2) perform relatively worse on nonverbal fluency measures and demonstrate greater difficulty regulating cardiovascular functioning, and (3) demonstrate relatively lower nonverbal fluency scores and increased physiological arousal when presented with the nonverbal fluency task and cold pressor stimulus simultaneously. The results are evaluated using three perspectives: Heller's (1993) hypothesis, Kinsbourne's Functional Cerebral Distance principle, and lateralized regulation of the sympathetic and parasympathetic nervous system. The results only partially supported the right hemisphere activation hypothesis for anxious individuals, as many of the significant results were counter to hypotheses. Specifically, high anxious men demonstrated lower verbal fluency scores and greater heart rate during the combined stimulus of the cold pressor and verbal fluency task. The data are supportive of relative anterior deactivation among high anxious men. The discussion extends the findings to present questions regarding cerebral regulation of the ANS. Future experiments which may add to the current understanding of lateralized regulation of the sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) are suggested.Ph. D.
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Santos, Monica Cena de Sousa. "Hemisferectomia na vida adulta como modelo para o estudo das assimetrias cerebrais no controle da reatividade emocional e atividade locomotora em camundongos." Universidade do Estado do Rio de Janeiro, 2013. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=9326.
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Evidências sugerem que a lateralização cerebral é uma característica fundamental dos vertebrados. Nos seres humanos, tem sido sugerido que o hemisfério direito é especializado no processamento de informação emocional negativa e o hemisfério esquerdo no controle da função motora. Em roedores, evidências de lateralização hemisférica são escassas. Diante disso, utilizamos a hemisferectomia para avaliar a importância relativa de cada hemisfério no controle emocional e na atividade motora espontânea em camundongos. Machos adultos foram submetidos à hemisferectomia direita (HD), hemisferectomia esquerda (HE) ou a simulação da cirurgia (SHAM). Para ajudar na interpretação dos resultados, uma amostra adicional de camundongos foi submetida à aspiração unilateral da área frontoparietal esquerda (FPE), da área frontoparietal direito (FPD) ou a simulação da cirurgia (CONT). Quinze dias após a cirurgia, a reatividade emocional e a ambulação foram avaliadas no teste de campo aberto durante 10 minutos (dividido em intervalos de 1 min). A arena de campo aberto consistiu em uma caixa de polipropileno, cujo fundo foi dividido em 16 retângulos do mesmo tamanho. O número total de retângulos cruzados pelo animal foi utilizado como a medida da atividade locomotora espontânea. Considerando-se que os camundongos evitam áreas abertas, a locomoção no centro e o tempo despendido nos retângulos centrais foram utilizados para avaliar a reatividade emocional. Em relação à atividade locomotora as duas técnicas cirúrgicas revelaram assimetrias na direção oposta. A atividade locomotora do grupo HE aumentou ao longo do período de teste e foi maior do que a dos grupos HD e SHAM. Em contraste, a atividade locomotora do grupo FPD diminuiu ao longo do período de teste e foi superior a ambos os grupos, FPE e CONT. Em relação à reatividade emocional, o grupo HE passou menos tempo na área central que os grupos HD e CONT. Não foram observadas diferenças entre FPD, FPE e o grupo CONT. Os nossos resultados sugerem que os dois hemisférios contribuem de forma assimétrica para controlar de reatividade emocional e para controlar de atividade motora em camundongos. De forma semelhante ao que é observado em humanos, o hemisfério direito dos camundongos foi mais associado com o processamento de informação emocional negativa. Em relação aos dados de hiperatividade, as diferenças observadas entre os animais hemisferectomizados e com lesão frontoparietal sugerem que mais de um circuito (ou sistema) lateralizado pode mediar a atividade locomotora espontânea.Evidence exists indicating that cerebral lateralization is a fundamental feature of all vertebrates. In humans, it has been suggested that the right hemisphere is involved in processing negative emotional information and the left hemisphere is involved in control of motor function. In rodents, evidence for hemispheric lateralization is sparse. In this regard, here, we used unilateral hemispherectomy to study the relative importance of each hemisphere in controlling emotion and spontaneous motor activity in mice. Adult male mice were submitted to right hemispherectomy (RH), left hemispherectomy (LH) or sham surgery (SHAM). To help the interpretation of results an addition sample of mice was submitted to unilateral suction of left frontoparietal area (LFP), right frontoparietal area (RFP) or sham surgery (CONT). Fifteen days after surgery, both the emotional reactivity and the spontaneous locomotor activity were assessed in the open field test 10 min (divided into 1 min intervals). The open field arena consisted of a polypropylene box in which the floor was divided into 16 same-sized rectangles. The total number of rectangles crossed was used as the measure of spontaneous locomotor activity. Considering that mice avoid open areas, the ambulation in the center and time spent in the central rectangles were used to assess emotional reactivity. Regarding locomotor activity, the two surgical techniques reveal asymmetries in opposite direction. The locomotor activity of LH, which increased along the test period, was higher than both RH and SHAM. In contrast, the locomotor activity of RFP which decreased along the test period was higher than both LFP and CONT. Regarding emotional reactivity, the LH group spent less time in the central area than both RH and SHAM groups. No differences were observed between LFP, RFP and CONT groups. Our results suggest that the two hemispheres contribute asymmetrically to control of emotional reactivity and to control of motor activity in mice. Similarly to what is observed in humans, the right hemisphere of mice was more involved in processing negative emotional information. Regarding locomotor hyperactivity, the differences observed between hemispherectomized and frontoparietal-lesioned mice suggest that multiple lateralized circuits (or systems) may underlie spontaneous locomotor activity.
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Flindall, Jason. "Manual asymmetries in the kinematics of reach-to-grasp actions." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Kinesiology and Physical Education, c2012, 2012. http://hdl.handle.net/10133/3359.
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The purpose of this thesis was to investigate manual asymmetries in the reach-to-grasp movement based on two hypotheses: 1) manual asymmetries are resultant from asymmetries in the dorsal vision-for-action system; and 2) manual asymmetries are contingent on task difficulty. Participants grasped glasses of water under different visual-feedback conditions. Demand was manipulated by varying the level of the water contained in the glass. Hand asymmetries of the reach-to-grasp movement were studied through kinematic analyses. Visual feedback availability and task demand affected all kinematic measures. Manual asymmetries were found in peak velocity, movement time, and variability of maximum grip aperture. Consistent with reach-to-point literature, reach-to-grasp actions were faster and more accurate when performed with the right hand and when guided by the dorsal vision-for-action system. The results of the thesis provide support for a theory of left-hemisphere specialization for the visual control of actions.xiv, 121 leaves : ill. ; 29 cm
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Demaree, Heath Allan. "Analysis of Quantitative Electroencephalographic and Cardiovascular Responses to Stress Amoung Low- and High-Hostiles." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30334.
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This experiment was primarily designed to identify higher cortical correlates of cardiovascular arousal. Low- and high-hostile, right-handed, undergraduate men were identified using the Cook Medley Hostility Scale (CMHS). All participants (N = 30) completed the cold pressor paradigm. Cardiovascular (heart rate, systolic blood pressure, and diastolic blood pressure) and electroencephalographic (beta magnitude) data were collected before and after the stressor.
As predicted, high-hostiles showed greater increases of heart rate and systolic blood pressure to the stressor relative to low-hostiles. The primary findings of this research include significantly greater beta magnitude recorded by the T3, relative to F7, electrode among low-hostiles. This may suggest that low-hostiles experience left-frontal disinhibition of left-temporal regions, thereby strengthening cardiovascular regulation during the cold-pressor stress. In addition, irrespective of condition, high-hostiles evidenced significantly greater beta magnitude at regions corresponding to the F7 and F8 electrodes. This perhaps suggests that high-hostiles have a relative inability to increase their rostral modulation of posterior systems related to cardiovascular activity/regulation.
Low- and high-hostiles did not, however, evidence reliable differences in their ability to monitor cardiovascular arousal to the cold-pressor stress. Findings are discussed in terms of a systems approach, and pertinent future research is recommended.
This research did not support the prominent neuropsychological theories of cardiovascular regulation proposed by Heilman et al. (1993) and Tucker and Williamson (1984). Rather, the results may suggest that right- and left-cerebral mechanisms may be primarily responsible for sympathetic and parasympathetic cardiovascular arousal, respectively.Ph. D.
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Shenal, Brian Vincent. "The Dynamic Cerebral Laterality Effect: Group Differences in Hostility, Cardiovascular Regulation, and Sensory Recognition." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36661.
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This experiment tested two hypotheses linking the right cerebral regulation of hostility and cardiovascular arousal. First, replication of previous research supporting heightened cardiovascular (systolic blood pressure, diastolic blood pressure, and heart rate) reactivity among high hostile participants was attempted. Second, dynamic variations in functional cerebral asymmetry in response to pain (cold pressor) and emotional linguistic processing was measured. Low- and high-hostile participants were identified using the Cook Medley Hostility Scale (CMHS). All participants completed either the negative affective verbal learning test (Experiment 1) or the cold pressor paradigm (Experiment 2). Cardiovascular measures (SBP, DBP, and HR) were recorded and either dichotic listening procedures (Experiment 1) or tachistoscopic lexical recognition procedures (Experiment 2) were administered before and after the stressor. The primary finding of this research was greater left cerebral activation (decreased cardiovascular reactivity) following the dichotic phoneme listening and the tachistoscopic lexical recognition tasks and greater right cerebral activation following pain (cold pressor) and emotionally linguistic (affective verbal learning) stressors.Master of Science
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Comer, Clinton S. "Cerebral Laterality, Emotion, and Cardiopulmonary Functions: An Investigation of Left and Right CVA Patients." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/56981.
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Stroke, or cerebrovascular accident (CVA), is a prominent cause of long term disability in the United States. It has been evidenced that the outcome of a CVA patient differs as a function of the cerebral hemisphere that is damaged by the stroke, especially in terms of emotional changes. The Right Hemisphere Model of Emotion posits that the right hemisphere is specialized for processing emotional content, regardless of valence. In contrast, the Bi-Hemispheric Model of Emotion posits that each hemisphere has its own emotional specialization. The current experiment tested the competing predictions of the two theoretical perspectives in a mixed sample of left cerebrovascular accident (LCVA) patients and right cerebrovascular accident (RCVA) patients using a Dichotic Listening task and the Affective Auditory Verbal Learning Test (AAVLT). Heart Rate (HR) and Pulse Oxygen Saturation (SpO2) were also recorded as sympathetic measures. It was expected that the predictions of the Bi-Hemispheric Model would be supported. A series of mixed design ANOVAs were used to analyze the data. Results revealed that both groups may have exhibited decreased auditory detection abilities in the ear contralateral to CVA location. Additionally, CVA patients recalled significantly more positive words, than negative or neutral words, and exhibited a significant learning curve. LCVA patients exhibited a recency effect, while RCVA patients exhibited a heightened primacy effect. Findings from HR and SPO2 measures suggested a parasympathetic response to neutral information as well as an impaired sympathetic response to negative information in RCVA patients. Taken together these results lend partial support to the hypotheses drawn from the Bi-Hemispheric Model of Emotion, as evidenced by the diametrically opposite effects in these groups, which appears to reflect opposing cerebral processes.Ph. D.
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Barrick, Thomas R. "Automatic image analysis methods for quantification of cerebral asymmetry : investigation of sexual dimorphism and schizophrenia." Thesis, University of Liverpool, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399212.
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Shore, Robert. "A functional characterisation of the PCSK6 locus associated with handedness." Thesis, University of St Andrews, 2016. http://hdl.handle.net/10023/15719.
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Humans display a 90% population level bias towards right-handedness, implying the vast majority of people have a left-hemisphere dominant for motor control. Although handedness presents a weak, but very consistent heritability across the literature (estimated to be approximately 25%), to date few genetic loci associated with this complex trait have been identified and replicated in subsequent studies. One such gene which has been found to be associated with handedness and subsequently replicated is PCSK6, most recently through a quantitative GWAS (P < 0.5*10−8, Brandler et al. (2013)). Interestingly, PCSK6 is known to activate Nodal, a morphogen involved in a highly conserved bilaterian pathway known to regulate left-right body axis determination. Here I present the first molecular characterisation of a handedness-associated region by conducting a detailed functional analysis of the PCSK6 locus, combining genetic analysis, in silico prediction and molecular assays to investigate how common genetic variants influence handedness-related phenotypes. Specifically, I defined the associated locus to be 12.7 kb in size, spanning a predicted 1.8 kb bidirectional promoter which controls the expression of both an antisense long non-coding RNA (lncRNA), and a novel short PCSK6 isoform. A series of luciferase-expressing constructs were generated to characterise the promoter, identifying a minimal sequence capable of driving transcription in a sense strand direction. I have demonstrated experimentally that one of the top associated markers in previous GWA studies, rs11855145, directly creates/disrupts a suspected transcription factor bind site in the vicinity of this bidirectional promoter. Further functional studies of the genetic variation within PCSK6 may help explain the molecular regulatory mechanisms affecting gene expression. This project provides a model for assays to study other GWAS-nominated candidate genes, and in particular for establishing the role of noncoding variants. The findings from this study support the role of common variants in influencing complex phenotypes, such as handedness.
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Carr, Vaughan. "Electrodermal indices of information processing and functional cerebral asymmetry in schizophrenia : a comparison with affective disorder /." Title page, table of contents and summary only, 1987. http://web4.library.adelaide.edu.au/theses/09MD/09mdc312.pdf.
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Dorsaint-Pierre, Raquel. "Revisiting the function-structure polemic : examining the relationship between language lateralization and the neuroanatomical asymmetries in Heschl's gyrus, the planum temporale, and Broca's area." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85153.
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This doctoral work consists of several studies that investigated the relationship between language lateralization and structural asymmetries found in auditory and language-related regions of the human brain. Language lateralization was determined via the intracarotid Sodium Amytal procedure in epilepsy patients. In study 1, three groups of patients were investigated: a left speech group (LSG); a right speech group (RSG); and a bilateral speech group (BSG). Two auditory cortex regions: Heschl's gyrus (HG) and the planum temporale (PT) were labelled on the magnetic resonance imaging scan of each subject. Additionally, an automatic voxel-based morphometry (VBM) analysis was performed. The overall findings suggested that the structural asymmetries found in the auditory regions did not clearly and directly relate to language lateralization. The VBM analysis, however, revealed a grey matter concentration difference in the region of Broca's area favoring the left hemisphere (LH) in the LSG, and the right hemisphere (RH) in the RSG. That structural difference did relate to language lateralization and was further investigated in studies 2 and 3. Previously collected positron emission tomography data were examined in these two studies. Three regions of interest (ROI) analyses and one group average analysis were performed. Activation related to various speech tasks was examined. The ROI analyses revealed a significant activation difference favoring the LH for two targeted speech-task subtractions but only for the LSG. The group analysis, in contrast, revealed that the LSG showed a functional asymmetry favoring the LH, and that the RSG showed a functional asymmetry favoring the RH. Overall, the present results provided only partial evidence for a relationship existing between structural asymmetry in Broca's area and language lateralization. The structural asymmetries found in HG and the PT, in contrast, did not clearly and directly relate to language
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Williamson, John Bonar. "Differential Efficts of Hostility on Frontal Lobe Performance: A dual task approach with Fluency and Cardiovascular Regulation." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/9779.
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The influence of levels of hostility on the lateralized tasks of verbal and nonverbal fluency, and the concurrent cerebral regulation of autonomic nervous system functioning was examined. Forty-eight right-handed males were recruited for participation with half classified as low-hostile and the other half as high-hostile. Previous research has shown that high-hostile males, at rest, have greater right hemisphere arousal relative to low-hostile males. It was predicted that this heightened, at rest, arousal would lead to reduced capacity to perform right hemisphere lateralized proximal tasks simultaneously.
Two commonly used neuropsychological tests sensitive to left and right anterior cerebral systems are the Controlled Oral Word Association Test and the Ruff Figural Fluency Test (RFFT) respectively. Nonverbal fluency, verbal fluency, and perseverative errors were assessed using these measures. Cardiovascular measures of systolic and diastolic blood pressure, and heart rate were assessed using oscillometric technique with a digital blood pressure meter.
A dual-task methodology was used to evaluate these anterior and posterior cerebral systems simultaneously. Since cardiovascular regulation and nonverbal fluency are both right-frontal tasks, it was predicted that high hostile men would evidence increased interference on cardiovascular regulation concurrent with the nonverbal fluency task in comparison with low hostile men. It was also predicted that high-hostile males would display more perseverative errors than low- hostile males on the nonverbal fluency task as a function of regulatory interference.
The results supported a capacity-limited prediction in high-hostile males. High-hostile males evidenced significantly heightened systolic blood pressure responses during the nonverbal fluency task in comparison with low hostile males. Further, high-hostile males displayed more perseverative errors in nonverbal fluency than did the low-hostile males. No differences were found in the overall fluency scores (verbal or nonverbal). These results partially support the expectation that differences exist between high and low hostile males for right frontal functioning. Moreover, these differences manifest in multiple domains of associated right frontal functioning. These findings extend the evidence for the proposed anterior-posterior inhibition model of hostility.Master of Science
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Rodriguez, Lina Maria Perilla. "Efeitos de bandas de frequência espacial alta e baixa no reconhecimento de faces em campo visual lateralizado." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/59/59134/tde-11092013-112028/.
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O presente trabalho teve por objetivo pesquisar os efeitos que as bandas de freqüência espacial alta e baixa têm no reconhecimento de faces em campo visual lateralizado. Foram distribuídos aleatoriamente 40 participantes em dois grupos. Os voluntários observaram 14 fotos de faces sem filtragem até memorizá-las. A seguir foram apresentadas 56 fotos de faces com filtragens de freqüências espaciais, intercaladas aleatoriamente com apresentações de faces não mostradas anteriormente. Cada uma delas foi exibida na tela durante 300 ms mediante a metodologia de apresentação dicótica. O participante devia responder se a face mostrada pertencia ao grupo de fotos inicialmente observado. As freqüências de respostas permitiram calcular as curvas ROC (Receiver Operating Characteristic) e os parâmetros Az e da preconizado pela Teoria de Detecção de Sinal (MACMILLAN; CREELMAN, 2005) para as faces naturais, faces compostas de freqüências espaciais baixas e faces compostas de freqüências espaciais altas. Os resultados obtidos mostram que as faces Originais foram melhor reconhecidas do que as faces com Freqüências Espaciais Altas (FEA) ou Freqüências Espaciais Baixas (FEB). Ao contrário do achado na literatura, o Hemisfério Esquerdo (HE) teve uma tendência a reconhecer mais eficazmente as faces do que o Hemisfério Direito (HD), independente da condição de filtragem. O HD é igualmente competente do que o HE para processar FEB, mas pior do que o HE para processar FEA. Quanto à performance por gênero, tanto homens quanto mulheres tiveram um desempenho similar quando as faces foram processadas com o HD. O desempenho das mulheres ficou de acordo com a hipótese da FE, pois o reconhecimento que fizeram para as faces com FEA foi melhor do que para as que tinham predomínio de FEB. Os homens, mesmo com o HE, fizeram um reconhecimento melhor das faces com predomínio de FEB do que das faces com FEA.This study was made with the objective of investigate the effects of high and low spatial frequency bands in face recognition in lateralized visual field. 40 participants were randomly distributed in two groups. The volunteers viewed fourteen non-filtered pictures of faces until they managed to memorize them. After that, fifty six spatial frequency filtered pictures of faces were presented randomly interspersed with pictures of faces previously showed. Each one of them was exhibited in the screen for three hundred milliseconds using the dichotic presentation procedure. The participant should answer whether the face presented belonged to the group of pictures initially viewed. The frequency of responses allowed to calculate the ROC (Receiver Operating Characteristic) Curves and the Az and da parameters praised by the Signal Detection Theory (Macmillan; Creelman, 2005) for natural faces, low spatial frequency composed faces and high spatial frequency composed faces. Results showed that original faces were better recognized than faces with high spatial frequencies (HSF) and low spatial frequencies (LSF). Differently from literature, the left hemisphere was more accurate than the right to recognize faces, regardless of the filter condition. The RH was equivalent to the LH to process LSF, but worse than the LH to process HSF. Concerning the performance of the genders, men and women judged faces in a very similar way when they used the RH. The performance of women agreed with the FE hypothesis, being faces with HSF recognized better than faces with LSF. Men, even using the LH, were more accurate to recognize faces with LSF than HSF.
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Burghy, Cory A. "Family environmental risk, frontal brain asymmetry, and social-emotional functioning for children living in poverty." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1317326181&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Alves, Nelson Torro. "Assimetria cerebral na percepção de expressões faciais de valência positiva e negativa." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/59/59134/tde-20092013-115902/.
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A técnica de campo visual dividido foi utilizada na análise dos padrões de assimetria cerebral para a percepção de expressões faciais de valência positiva e negativa. Oitenta universitários destros (65 mulheres, 15 homens) foram distribuídos em cinco grupos experimentais com o objetivo de se investigar separadamente a percepção de expressões de alegria, medo, surpresa, tristeza e da face neutra. Em cada apresentação de estímulo, uma face alvo e uma face distratora eram apresentadas à direita ou à esquerda de um ponto de fixação localizado no centro da tela do computador. O tempo de apresentação dos estímulos foi de 150 ms e os participantes tiveram que determinar o lado (esquerdo ou direito) em que havia sido apresentada a face alvo, utilizando um mouse para responderem aos estímulos. As análises estatísticas de tempo de reação e erros de julgamento indicaram não haver diferenças entre o desempenho de homens e mulheres na tarefa experimental. Expressões faciais de alegria e medo foram identificadas mais rapidamente quando apresentadas no campo visual esquerdo, indicando uma possível vantagem do hemisfério direito na percepção destas emoções. Menores tempos de reação e erros de julgamento foram observados para as condições de pareamento em que faces emocionais foram apresentadas no campo visual esquerdo e faces neutras no campo visual direito. A análise dos pareamentos entre faces indicou que faces neutras e de alegria são percebidas mais rapidamente e com maior acerto que faces de medo e tristeza. Embora não tenha havido uma vantagem do hemisfério direito para a percepção de todas as expressões faciais, os resultados deste estudo tendem a concordar com a hipótese do hemisfério direito para o processamento emocional.The divided visual field technique was used to analize the patterns of brain asymmetry in the perception of positive and negative facial expressions. Eighty undergraduate students (65 female, 15 male) were distributed in five experimental groups in order to investigate separately the perception of expressions of happiness, surprise, fear, sadness, and neutral. In each trial, a target and a distractor expression were presented in a computer screen during 150 ms and participants had to determine the side (left or right) on which the target expression was presented using a mouse to respond to the stimuli. Time reaction and judgment errors analysis showed no differences between men and womens performance in experimental task. Results indicated that expressions of happiness and fear were identified faster when presented on the left visual field, suggesting an advantage of the right hemisphere in the perception of these expressions. Fewer judgment errors and faster reaction times were observed for the matching condition in which emotional faces were presented on the left visual field and neutral faces on the right visual field. Analysis of the pairs of faces indicated that neutral and happy faces were perceived faster and more accurately than faces of fear and happiness. Although an advantage of the right hemisphere was not occurred for the perception of all expressions, results tend to support the right hemisphere hypothesis for emotional processing.
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Shtyrov, Yury. "New aspects of the cerebral functional asymmetry in speech processing as revealed by auditory cortex evoked magnetic fields." Helsinki : University of Helsinki, 2000. http://ethesis.helsinki.fi/julkaisut/hum/psyko/vk/shtyrov/.
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Higgins, Dane A. "Cardiovascular Reactivity to Speech Processing and Cold Pressor Stress: Evidence for Sex Differences in Dynamic Functional Cerebral Laterality." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/35146.
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This experiment investigated sex differences in dynamic functional cerebral laterality effects on cardiovascular reactivity and dichotic listening in response to a stressor (a cold pressor). 120 right-handed undergraduate men (N = 60) and women (N = 60) underwent physiological measurements of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) before and after exposure to the cold pressor and a phonemic dichotic listening task. Functional cerebral laterality was assessed through the administration of the phonemic dichotic listening task. Group differences in dynamic functional cerebral laterality were predicted.
Findings indicated a sex by focus interaction effect where men's, but not women's, systolic blood pressure increased significantly when focusing on sounds presented at the left ear during the dichotic listening task. Also, a compartmentalized, dynamic response in dichotic listening test performance was evidenced in both men and women (as both experienced increased accuracy at the right, but not left, ear), brought about as a function of the cold pressor. Men and women both evidenced increased cardiovascular reactivity, with men experiencing significantly more cardiovascular reactivity (SBP) than women in response to cold pressor pain. Women were also able to identify significantly more speech sounds presented to the left ear than men, and they were able to dynamically increase accuracy at the targeted ear identified within each focus group (left or right). Speech sounds processing (dichotic listening task) significantly decreased men's, but not women's, systolic blood pressure. These results contribute to the literature on sex differences in functional cerebral laterality.Master of Science
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Júnior, Rui de Moraes. "Reconhecimento de faces com filtragens de frequências espaciais altas e baixas nos hemicampos visuais direito e esquerdo." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/59/59134/tde-17012013-211718/.
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O presente estudo teve por objetivo investigar se o reconhecimento de faces ocorre prioritariamente por processamento analítico ou holístico nos hemisférios cerebrais em homens e mulheres por meio do estudo do espectro de frequência espacial. Para isso, no Experimento I, 40 voluntários (20 mulheres) realizaram duas sessões. Em cada uma delas foram memorizadas 14 faces para uma tarefa de reconhecimento. Nesta, cada face foi apresentada por 300 ms, e em uma das sessões as imagens foram apresentadas somente no hemicampo visual direito, e noutra só no hemicampo visual esquerdo por meio de uma adaptação do método do campo visual dividido. A tarefa dos participantes foi assinalar o grau de confiabilidade de sua resposta (confidence rating method) ao discriminar as faces memorizadas de outras inéditas. Os estímulos da tarefa de reconhecimento foram apresentados em três condições: (1) em frequências espaciais altas, FEAs, (2) em frequências espaciais baixas, FEBs, e (3) sem filtragem, SFE. As frequências de respostas aos graus de confiabilidade permitiram calcular as curvas ROC e os parâmetros Az e da da Teoria de Deteção de Sinal. Por meio destes, foi comparado o desempenho do reconhecimento facial nas diferentes faixas do espectro espacial. De maneira complementar, foi realizado uma ANOVA para testar a diferença dos tempos de resposta no reconhecimento entre as filtragens. Não foi evidenciada especialização hemisférica no reconhecimento de faces com filtragem espacial. Mas homens, de modo tênue, perceberam melhor faces em FEBs e mulheres em FEAs. Para verificar se este resultado não se deu em função da apresentação lateralizada, foi realizado o Experimento II, nos moldes de uma sessão experimental do Experimento I, mas com apresentação central. Vinte voluntários (10 mulheres) participaram do experimento. Novamente, homens e mulheres foram mais sensíveis às faces em FEBs e FEAs, respectivamente. Deste modo, conclui-se que homens utilizam mais recursos holísticos e mulheres, por sua vez, operações analíticas. Os resultados dão bases para a não ocorrência de especialização hemisférica de frequencias espaciais no reconhecimento de faces em longos tempos de exposições. A diferença de sexo observada e nos atenta para a necessidade de controle amostral por sexo em pesquisas da área.This study aimed to investigate whether face recognition occurs primarily by analytic or holistic processing in the cerebral hemispheres of men and women through the study of the spatial frequency spectrum. Therefore, in Experiment I, 40 volunteers (20 women) performed two sessions. In each of, 14 faces were memorized for a recognition task and each face was presented for 300 ms. Images were presented only in the right visual hemifield in a session, and in another only in the left visual hemifield by means of an adaptation of the method of divided visual field. The participants task was to assign the reliability of their response (confidence rating method) to discriminate the study faces from distractors. The recognition task stimuli were presented in three conditions: (1) at high spatial frequencies, FEAs, (2) at low spatial frequencies, FEBs, and (3) unfiltered, SFE. The frequencies of responses to the degree of reliability used to calculate ROC curves and parameters Az and da of the Signal Detection Theory compared the performance of face recognition in different bands of the spectrum. In a complementary way, an ANOVA was conducted to test response times differences in the recognition between filtering. There was no evidence of hemispheric specialization in face recognition with spatial filtering. But men had better performance in recognizing faces in FEBs and women faces in FEAs. To verify that this result was not in function of lateralized presentation, Experiment II was conducted, along the lines of an experimental session of Experiment I, but with central presentation. Twenty volunteers (10 women) participated in the experiment. Again, men and women were more sensitive to faces in FEBs and FEAs, respectively. Thus it follows that men use holistic resources and women analytical operations. The results provide no basis for the occurrence of hemispheric specialization of spatial frequencies in face recognition over long exposure times. The sex difference observed brings us to the need for control sample by sex in spatial frequency research.
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Rodling, Wahlström Marie. "Severe cerebral emergency : aspects of treatment and outcome in the intensive care patient." Doctoral thesis, Umeå universitet, Anestesiologi och intensivvård, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-21065.
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Severe Traumatic Brain Injury (TBI) and aneurysmal Subarachnoid Hemorrhage (SAH) are severe cerebral emergencies. They are common reasons for extensive morbidity and mortality in young people and adults in the western world. This thesis, based on five clinical studies in patients with severe TBI (I-IV) and SAH (V), is concentrated on examination of pathophysiological developments and of evaluation of therapeutic approaches in order to improve outcome after cerebral emergency. The treatment for severe TBI patients at Umeå University Hospital, Sweden is an intracranial pressure (ICP)-targeted therapy according to “the Lund-concept”. This therapy is based on physiological principles for cerebral volume regulation, in order to preserve a normal cerebral microcirculation and a normal ICP. The main goal is to avoid development of secondary brain injuries, thus avoiding brain oedema and worsened microcirculation. Study I is evaluating retrospectively 41 children with severe TBI, from 1993 to 2002. The boundaries of the ICP-targeted protocol were obtained in 90%. Survival rate was 93%, and favourable outcome (Glasgow Outcome Scale, score 4+5) was 80%. Study II is retrospectively analysing fluid administration and fluid balance in 93 adult patients with severe TBI, from 1998 to 2001.The ICP-targeted therapy used, have defined fluid strategies. The total fluid balance was positive day one to three, and negative day four to ten. Colloids constituted 40-60% of total fluids given/day. Severe organ failure was evident for respiratory insufficiency and observed in 29%. Mortality within 28 days was 11%. Study III is a prospective, randomised, double-blind, placebo-controlled clinical trial in 48 patients with severe TBI. In order to improve microcirculation and prevent oedema formation, prostacyclin treatment was added to the ICP-targeted therapy. Prostacyclin is endogenously produced, by the vascular endothelium, and has the ability to decrease capillary permeability and vasodilate cerebral capillaries. Prostacyclin is an inhibitor of leukocyte adhesion and platelet aggregation. There was no significant difference between prostacyclin or placebo groups in clinical outcome or in cerebral microdialysis markers such as lactatepyruvate ratio and brain glucose levels. Study IV is part of the third trial and focus on the systemic release of pro-inflammatory mediators that are rapidly activated by trauma. The systemically released pro-inflammatory mediators, interleukin-6 and CRP were significantly decreased in the prostacyclin group versus the placebo group. Study V is a prospective pilot study which analyses asymmetric dimethylarginine (ADMA) concentrations in serum from SAH patients. Acute SAH patients have cerebral vascular, systemic circulatory and inflammatory complications. ADMA is a marker in vascular diseases which is correlated to endothelial dysfunction. ADMA concentrations in serum were significantly elevated seven days after the SAH compared to admission and were still elevated at the three months follow-up. Our results show overall low mortality and high favourable outcome compared to international reports on outcome in severe TBI patients. Prostacyclin administration does not improve cerebral metabolism or outcome but significantly decreases the levels of pro-inflammatory mediators. SAH seems to induce long-lasting elevations of ADMA in serum, which indicates persistent endothelial dysfunction. Endothelial dysfunction may influence outcome after severe cerebral emergencies.
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Branco, Danielle Paes Machado de Andrade. "Hemisferectomia unilateral na vida adulta como modelo para o estudo das assimetrias motoras em camundongos." Universidade do Estado do Rio de Janeiro, 2009. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4685.
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Em humanos, uma série de estudos vem sugerindo que o hemisfério esquerdo é particularmente importante no controle e execução de movimentos. De modo geral, lesões no hemisfério esquerdo promovem déficits motores mais pronunciados que lesões semelhantes no hemisfério direito. Neste trabalho utilizamos a hemisferectomia unilateral para avaliar a contribuição de cada hemisfério na função motora em camundongos. Camundongos Suíços adultos foram submetidos a hemisferectomia unilateral direita (HD) ou esquerda (HE) ou aos procedimentos de controle. Quinze dias após cirurgia, a coordenação motora de cada animal foi avaliada no teste da locomoção forçada em cilindro giratório (Rotarod). A latência para a queda do grupo controle foi significativamente maior que a do grupo HD e não diferiu da do grupo HE. Para auxiliar a interpretação dos resultados obtidos no ROTAROD, uma parte dos animais foi submetida a uma bateria adicional de testes comportamentais na seguinte seqüência: teste de campo aberto, avaliação qualitativa da assimetria sensório-motora, teste da grade elevada e teste de suspensão pela cauda. De modo interessante, no teste da grade elevada, enquanto o grupo HD apresentou o desempenho da pata traseira esquerda (contralateral à lesão) significativamente pior que o da direita, os grupos Controle e HE não apresentaram diferenças entre as duas patas traseiras. De modo análogo ao observado em humanos, nossos resultados sugerem uma ação assimétrica dos hemisférios cerebrais no controle da função motora em camundongos.A series of studies in humans have suggested that the planning and the control of movements are asymmetrically performed by the hemispheres. In general, lesions in the left hemisphere promote motor deficits that are more pronounced than similar lesions in the right hemisphere. In the present work, we used unilateral hemispherectomy to study the relative importance of each hemisphere in the control of movement in mice. Adult Swiss mice were submitted to right unilateral hemispherectomy (RH) or left unilateral hemispherectomy (LH) and sham surgery. Fifteen days after surgery, the motor coordination of each mouse was evaluated in the forced locomotion in rotating cylinder test (Rotarod). The latency to fall was significantly lower in right-hemispherectomized group as compared to control and did not differ from the left-hemispherectomized group. To help the interpretation of results obtained in the Rotarod test, a part of the sample was subjected to a additional battery of behavioral tests in the following sequence: open field test, qualitative assessment of sensory-motor asymmetry, foot fault test and tail suspension test. Interestingly, in the foot fault test, while the RH group showed significantly worse performance with the left hind limb (contralateral to the lesion) than with the right, the control group and the LH group showed no differences between both hind limbs. Similarly to what is observed in humans, our results suggest that the two hemispheres contribute asymmetrically to control of movement in mice.
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Castells, Navarro Laura, W. Southwell-Wright, Keith Manchester, and Jo Buckberry. "Interpretation of a probable case of poliomyelitis in the Romano-British social context." Archaeological reviews from Cambridge, 2017. http://hdl.handle.net/10454/17511.
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NoThis paper provides the results of re-evaluation of a young adult individual from the Romano-British cemetery of 76 Kingsholm, Gloucester with club foot defomity by (Roberts et al 2004). Our reanalysis revealed an extensive bilateral asymmetry involving the lower and upper limb, spine and cranium and a right scoliosis, indicating more than the lower limb was affected. Consideration of the position and shape of the articulated club foot indicated a positional rather than a developmental condition, probably due to unilateral paralysis. Differential diagnosis considered congenital and acquired neuromuscular conditions; we argue that poliomyelitis is the most likely cause. Poliomyelitis is secondary to the infection with poliovirus that can affect the motor neurons from the spinal cord, causing a flaccid paralysis without sensory affection. Because the virus affects individual nerves, the paralysis is muscle-specific causing muscle imbalances and poor posture which can result in deformities and muscle disuse atrophy. Shortening of the leg is the most characteristic sign, however other typical deformations are in the lower limbs are external rotation of the knee, knee hyperestension, ankle and foot deformities (all observed in K131). The evaluation of K131’s entheses and bone structure suggests that, in life, this individual showed physical deformities consisting of a possibly visible atrophy of the left arm and leg, asymmetric gait, clubfoot and slight scoliosis which would have affected not only his appearance but also his ability to move and perform certain tasks. K131’s burial treatment is entirely normative for the period and the wider cemetery context. This could suggest that despite their impairment, this individual was not necessarily marginalised within their social context. However, historical sources account for extensive marginalisation and cruel treatment of the disabled and deformed in this period. So, whilst K131 was buried in a normative manner, it is difficult to reach definitive conclusions regarding how this individual was treated by their contemporaries.
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Westergren, Amanda, and Tim Kammeborn. "Vänster- eller högerriktat ljus i reklamfilm, finns det en preferens? : En experimentell studie om ljussättningens laterala riktning i reklamfilm." Thesis, Högskolan Dalarna, Bildproduktion, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:du-30568.
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In accordance with an experimental setup this thesis investigates to what extent the participants' attitudes and aesthetic preferences are influenced by the lateral direction of light in moving image sequences. It is also investigated whether the participants' handedness correlates with their advertising evaluation. The purpose of the study is to generate new knowledge of potential biases in moving images that could be applied by image producers to create more compelling commercials. Our work is based on a transdisciplinary theoretical approach and the results are analyzed based on biopsychological, sociocultural and perceptual explanatory models. Three self-designed commercials with a left oriented illumination position were used as stimulus, the stimulus were also inverted horizontally. The participants were asked to assess their attitudes toward the commercials with either left or right oriented lighting. Two surveys were conducted: one with a within-subjects design and one with a between-subjects design, a total of 172 people participated. No significant difference between left and right oriented illumination position occurred in any of the groups for neither feelings toward ad, Aad , Ab , or PI. The results suggests that a bias does not occur in dynamic images, unlike the left oriented bias that has been reliably shown in previous studies that relate to still images. Nor could any correlation be established between reported attitudes and handedness.
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Sousa, Bruno Marinho de. "Assimetria cerebral funcional e sua relação com a excentricidade no campo visual nos tamanhos percebidos em fundos sem e com gradiente de textura." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/59/59134/tde-02112013-121640/.
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Estudos em assimetria cerebral funcional (ACF) apontam que há diferenças entre os hemisférios cerebrais esquerdo (HE) e direito (HD). O HE é especializado para tarefas de linguagem enquanto o HD para tarefas espaciais. Ainda, pode ocorrer uma superestimação de tamanho no campo visual esquerdo (CVE) em relação ao direito (CVD). Já homens possuem melhor desempenho do HD em tarefas espaciais, mas nas mulheres o desempenho dos hemisférios é equivalente. Ainda, há evidências que homens são menos sensíveis ao contexto dos estímulos que mulheres. Mas não é claro como a forma do estímulo, a variação da sua distância ao centro da tela (excentricidade) e se um gradiente de textura podem afetar a ACF. Com base nisso, o objetivo desse trabalho foi verificar se a variação da excentricidade influenciaria a percepção de tamanho de dois tipos de estímulos no CVE e CVD em homens e mulheres (Experimento I). Também (Experimento II) verificar se um gradiente de textura influenciaria um possível efeito observado no Experimento I. Nos dois experimentos a técnica do campo visual dividido foi associada ao método dos estímulos constantes (30 repetições) com escolha forçada de duas alternativas (qual o maior?). Os estímulos no Experimento I foram círculos (um padrão e sete de comparação) e elipses horizontais (uma padrão e sete de comparação). Esses estímulos foram contrabalanceados em ambos os hemicampos visuais. Os estímulos foram apresentados em três excentricidades (2,5°, 5° e 7,5°) por 100ms num fundo cinza, para universitários destros (10 homens e 10 mulheres por tipo de estímulo). No Experimento II foram apresentados círculos a 2,5° num gradiente de textura (dividido verticalmente e com mesmas informações de profundidade no CVE e CVD), para 10 mulheres universitárias destras. A partir dos dados foram calculados o Erro Relativo e o coeficiente angular sensibilidade discriminativa. Os resultados do Experimento I mostram que a média do erro relativo do CVD para círculos a 2,5° foi maior que a 5° e 7,5°. Nas mulheres houve diferenças entre os hemicampos visuais a 2,5°, sendo o CVD superestimado. Os coeficientes angulares foram maiores a 2,5° de excentricidade e maiores também para os círculos. Os homens apresentaram diferença nos coeficientes angulares para a variação da excentricidade, sendo a de 2,5° maior que 5° e 7,5°. Já as mulheres tiveram coeficientes maiores para círculos. Nos círculos os coeficientes das mulheres a 2,5° foram maiores que a 7,5°. Nas elipses os coeficientes a 2,5° foram maiores em geral e nos homens. Nesses ainda houve uma diferença no CVD, em que os coeficientes a 2,5° foram maiores que a 7,5°. No Experimento II o erro relativo não mostrou diferenças significativas, exceto na comparação de resultados com o Experimento I. Nessa análise a média do CVE foi menor que do CVD. Os coeficientes não apresentaram diferenças significativas. Esses resultados mostram que a ACF não é um efeito absoluto, mas sim dependente das características dos estímulos, da tarefa e pode ser influenciada por diferentes estratégias de homens e mulheres. Apesar de haver diferenças na sensibilidade discriminativa, elas não resultaram numa distorção perceptual. Isso sugere que além da percepção, medidas de sensibilidade também devem ser analisadas para a ACF. Ainda, o efeito do gradiente de textura se sobrepõe a ACF.Functional brain asymmetry (FBA) studies point out that there are differences between left (LH) and right (HD) brain hemispheres. LH is more specialized for processing language while HD for processing spatial information. Still, there may be a size overestimation in left visual field (LVF) compared to the right visual field (RVF).But men perform better on spatial tasks using LVF/RH, while women perform equivalently in each brain hemisphere. Also, there is evidence that men are less sensitive to stimuli context than women. However, it is not clear how the shape of the stimulus, variation of its distance from the center of the screen (eccentricity) and a texture gradient can affect FBA. Based on this, the aim of this study was to verify if eccentricity variation can influence size perception of two types of stimuli in LVF and RVF in men and women (Experiment I). Also (Experiment II) we investigate if a texture gradient can influence a possible effect observed in Experiment I. In both experiments we used the divided visual field technique associated with the method of constant stimuli (30 repetitions) with two alternative forced choice (\"what is the bigger?\"). Stimuli in Experiment I were circles (one standard and seven for comparison) and horizontal ellipses (one standard and seven for comparison). These stimuli were counterbalanced in both visual hemifields. Stimuli were presented at three eccentricities (2.5°, 5° and 7.5 °) for 100 ms on a gray background to right-handers (10 men and 10 women by stimulus type). In Experiment II circles were presented at 2.5° in a texture gradient (divided vertically and with same depth information on LVF and RVF), for 10 right-handed women. From data we calculated Relative Errors and psychometric slopes - discriminative sensitivity. Results of Experiment I show that relative error mean for 2.5° in RVF circles was greater than 5° and 7.5°. Women showed an overestimation for circles presented in RVF at 2.5° eccentricity. Slope coefficients were greater for 2.5 ° eccentricity and for circles. Men showed a difference in slope coefficients for eccentricity variation, with 2.5° mean greater than 5 ° and 7.5°. Women had higher coefficients for circles than ellipses. Mean circles coefficients were greater at 2.5° than 7.5° eccentricities. Mean ellipses coefficients were greater at 2.5° in general and in men. Men also showed a difference in RVF in which coefficients were greater at 2.5° than 7.5°. Experiment II showed only a difference for relative errors in comparison with Experiment I. These results show that FBA is not an absolute effect, but rely on stimuli characteristics and different strategies for men and women in the task. Although there are differences in discriminative sensitivity, they did not result in a perceptual distortion. This suggests that for FBA not only perceptual parameters should be analyzed, but also the psychometric slope and discrimination sensitivity. Furthermore, the effect of the gradient texture overlaps the FBA.
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Prieur, Jacques. "Chimpanzees' and gorillas' intraspecific gestural laterality : a multifactorial investigation." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S056/document.
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Nous avons étudié la latéralité gestuelle intraspécifique de chimpanzés et de gorilles captifs dans des contextes socio-écologiques proches des conditions naturelles de vie. Nous avons montré que les chimpanzés et les gorilles étudiés présentaient un biais populationnel pour la main droite pour la majorité des gestes les plus fréquents de leur répertoire. Par la mise en oeuvre d’une approche multifactorielle, nous avons montré pour la première fois que la latéralité gestuelle intraspécifique de ces primates était influencée par plusieurs facteurs et par leurs interactions: contexte de l’interaction (champs visuels de l’émetteur et du récepteur et contexte émotionnel), caractéristique du geste (modalité sensorielle, utilisation d'un outil de communication, degré de partage et durée du geste) et par certaines composantes sociodémographiques, particulièrement le rang hiérarchique de l’émetteur et son âge dans une moindre mesure. De plus, nous avons comparé la latéralité manuelle des chimpanzés lors de l'utilisation d'outil pour des actions non-communicatives et des gestes intraspécifiques. Notre analyse multifactorielle suggère que l’utilisation d’outil dans les gestes serait plus contrôlée par l'hémisphère cérébral gauche que l’utilisation d’outil dans des actions non-communicatives. Globalement, nos résultats vérifient le modèle de Ghirlanda et collègues (2009) selon lequel les biais de latéralité au niveau populationnel pourraient être expliqués par une stratégie évolutive stable basée sur les interactions intraspécifiques. Nos résultats sont également en accord avec les études mettant en évidence l'utilisation préférentielle de la main droite pour la communication gestuelle des primates non humains et suggérant que la latéralité gestuelle serait un précurseur de la spécialisation hémisphérique gauche pour le langage. En outre, nos résultats confortent l'hypothèse que certaines espèces de primates pourraient avoir un traitement spécifique de l’hémisphère gauche pour les gestes communicatifs distinct de celui des actions manuelles non-communicatives. Du point de l’évolution, nos résultats soulignent l’importance d’étudier en détail la latéralité intraspécifique en considérant des espèces de différents degrés de socialité et en prenant en compte des contextes socioécologiques proches des conditions naturelles ainsi que de multiples facteurs potentiellement influentsWe studied intraspecific gestural laterality of captive chimpanzees and gorillas in real-life social-ecological relevant contexts. We evidenced that chimpanzees (respectively gorillas) exhibited a right-hand bias at the population level for the majority of the most frequent gestures of their specific natural communication repertoire. By designing and applying a multifactorial approach, we showed for the first time that intraspecific gestural laterality of primates was influenced by several factors and their mutual intertwinement: interactional context (visual fields of both signaller and recipient as well as emotional context), gesture characteristic (sensory modality, use of a communication tool, sharing degree, and gesture duration) and by some socio-demographic components in particular signaller’s hierarchical rank, and to a lesser extent signaller’s age. Similarities but also some discrepancies between chimpanzees and gorillas may be related to the lateralization of emotional processing, to communication strategies, and to social selection pressures related to the social structure and dynamics of the study species. Moreover, we compared manual laterality of tool use by chimpanzees in both non-communication actions and intraspecific gestures. Our multifactorial analysis showed that tool-use in gestures appear to be governed more by the left cerebral hemisphere than tool-use in non-communication actions. Our findings support Ghirlanda and colleagues’ (2009) model postulating that population-level bias could be explained by an evolutionary stable strategy based on intraspecific interactions. Our results also agree with previous reports evidencing predominant right-hand use by nonhuman primates for gestural communication and suggesting that gestural laterality would be a precursor of the left-brain specialization for language. Furthermore, our results support the hypothesis that some primate species may have a specific left-cerebral system processing gestures distinct from the cerebral system processing non-communication manual actions. From an evolutionary point of view, our findings emphasize the importance to study intraspecific laterality in detail by considering species varying in their degree of sociality and taking into account real-life social-ecological contexts and multiple potentially influential factors
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Llorente, Espino Miquel. "Lateralidad Manual y Especialización Hemisférica en Chimpancés (Pan Troglodytes). Evaluación Observacional y Experimental." Doctoral thesis, Universitat Ramon Llull, 2011. http://hdl.handle.net/10803/9283.
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Les asimetries funcionals manuals han estat àmpliament estudiades en els primats no humans i altres espècies animals durant les últimes dues dècades. Resulta especialment interessant observar si l'especialització hemisfèrica cerebral, tan característica de l'ésser humà, està o no present i en quin grau dins del regne animal. En ximpanzés, trobem pocs treballs en què s'hagin avaluat les preferències manuals en una única mostra des d'un punt de vista observacional i experimental conjuntament, i cap en ambients intermedis (naturalitzats). El nostre objectiu ha estat comparar els patrons de preferència manual en situacions espontànies i experimentals en una mateixa mostra de ximpanzés i veure quines situacions incideixen sobre la direcció, intensitat i grau d'asimetria individual versus poblacional en els individus. En la fase observacional es van estudiar 53 comportaments espontanis unimanuals i bimanuals que feien referència a contextos tròfics, manipulatius-exploratoris, autodirigits, posturals i socials, entre d'altres. En la fase experimental es van avaluar dues tasques: una unimanual (simple reaching: recollida d'ítems petits d'aliment amb prensions de precisió) i una altra bimanual (tube task: extracció bimanual d'aliment d'un tub). Durant la fase observacional es van dur a terme 2.226 sessions (2005 a 2008: 33 mesos). La fase experimental va tenir una durada total de 4 mesos (2007). La mostra estava formada per un grup de 14 ximpanzés (Pan troglodytes) allotjats al Centre de Recuperació de Primats de la Fundació Mona (Girona). En ambdues fases es va utilitzar un mostreig focal amb registre activat per transicions. Globalment, tant durant la fase observacional com experimental, la major part de la mostra va presentar preferències individuals laterals de manera significativa. Es van comparar els índexs de lateralitat per a les quatre condicions d'estudi: unimanual-espontani (UES), bimanual-espontani (BES), unimanual-experimental (UEX) i bimanual-experimental (BEX). No es van trobar diferències en la direcció de les preferències entre les quatre condicions tot i que sí en la intensitat de la lateralització. D'aquesta manera, la intensitat de la preferència manual era major en les accions bimanuals que en les unimanuals, i també en les tasques experimentals que en les espontànies. L'ús d'instruments i el tipus de prensió també van augmentar la intensitat de les preferències encara que no van tenir cap efecte sobre la direcció d'aquestes. Es va detectar una asimetria dretana poblacional en les accions bimanuals espontànies però no en les experimentals. També es va detectar una asimetria dreta a nivell poblacional en tenir en compte totes les tasques conjuntament. D'aquesta manera, ha estat la primera ocasió que s'evidencia que els ximpanzés allotjats en ambients intermedis són dretans a nivell poblacional. En conclusió, els ximpanzés presentarien un patró de lateralització homòleg al dels éssers humans, sobretot en aquelles accions que impliquen una complexitat en la seva execució (bimanualitat, instrumentalitat i precisió) i que són les més rellevants per entendre el procés d'hominització conductual d'aquest tret a Homo sapiens.Las asimetrías funcionales manuales han sido ampliamente estudiadas en los primates no humanos y otras especies animales durante las últimas dos décadas. Resulta especialmente interesante observar si la especialización hemisférica cerebral, tan característica del ser humano, está o no presente y en qué grado dentro del reino animal. En chimpancés, encontramos pocos trabajos en los que se hayan evaluado las preferencias manuales en una única muestra desde un punto de vista observacional y experimental conjuntamente, y ninguno en ambientes intermedios (naturalizados). Nuestro objetivo ha sido comparar los patrones de preferencia manual en situaciones espontáneas y experimentales en una misma muestra de chimpancés y ver qué situaciones inciden sobre la dirección, intensidad y grado de asimetría individual versus poblacional en los individuos. En la fase observacional se estudiaron 53 comportamientos espontáneos unimanuales y bimanuales que hacían referencia a contextos tróficos, manipulativos-exploratorios, autodirigidos, posturales y sociales, entre otros. En la fase experimental evaluaron dos tareas: una unimanual (simple reaching: recogida de ítems pequeños de alimento con prensiones de precisión) y otra bimanual (tube task: extracción bimanual de alimento de un tubo). Durante la fase observacional se llevaron a cabo 2226 sesiones (2005 a 2008: 33 meses). La fase experimental tuvo una duración total de 4 meses (2007). La muestra estaba formada por un grupo de 14 chimpancés (Pan troglodytes) alojados en el Centro de Recuperación de Primates de Fundación Mona (Girona). En ambas fases se utilizó un muestreo focal con registro activado por transiciones. Globalmente, tanto durante la fase observacional como experimental, la mayor parte de la muestra presentó preferencias individuales laterales de manera significativa. Se compararon los índices de lateralidad para las cuatro condiciones de estudio: unimanual-espontáneo (UES), bimanual-espontáneo (BES), unimanual-experimental (UEX) y bimanual-experimental (BEX). No se encontraron diferencias en la dirección de las preferencias entre las cuatro condiciones aunque sí en la intensidad de la lateralización. De esta manera, la intensidad de la preferencia manual era mayor en las acciones bimanuales que en las unimanuales, y también en las tareas experimentales que en las espontáneas. El uso de instrumentos y el tipo de prensión también aumentaron la intensidad de las preferencias aunque no tuvieron ningún efecto sobre la dirección de éstas. Se detectó una asimetría diestra poblacional en las acciones bimanuales espontáneas aunque no en las experimentales. También se detectó una asimetría diestra a nivel poblacional al tener en cuenta todas las tareas conjuntamente. De esta manera, ha sido la primera ocasión que se evidencia que los chimpancés alojados en ambientes intermedios son diestros a nivel poblacional. En conclusión, los chimpancés exhibirían un patrón de lateralización homólogo al de los seres humanos, sobre todo en aquellas acciones que implican una complejidad en su ejecución (bimanualidad, instrumentalidad y precisión) y que son las más relevantes para entender el proceso de hominización conductual de este rasgo en Homo sapiens.
Manual functional asymmetries have been extensively studied in nonhuman primates and other animals for the last two decades. It is particularly interesting to see if brain hemispheric specialization, so characteristic human beings, is present or not and to what extent within the animal kingdom. In chimpanzees, there are few studies that have assessed hand preferences in a single sample from an experimental and observational standpoint, and none have been done within intermediate (naturalized) environments. Our objective was to compare the patterns of hand preference for spontaneous and experimental actions in the same sample of chimpanzees and observe what situations impact on the direction, strength and the degree of individual versus population asymmetry in individuals. In the observational phase, we studied 53 spontaneous unimanual and bimanual behaviors related to feeding contexts, manipulative-exploratory, self-directed, postural and social, among others. In the experimental phase, we evaluated two tasks: unimanual (simple reaching: collection of small items of food with precision grips) and bimanual (tube task: bimanual removal of food from a tube). During the observational phase, we conducted 2.226 sessions (from 2005 to 2008: 33 months). The experimental phase lasted a total of four months (2007). The sample was composed of a group of 14 chimpanzees (Pan troglodytes) housed at the Mona Foundation Primate Rehabilitation Center (Girona). In both phases, a focal sampling method was used. Overall, during both observational and experimental phases, the majority of the sample showed significant individual lateral preferences. We compared the handedness index for four study conditions: unimanual-spontaneous (UES), bimanual-spontaneous (BES), unimanual-experimental (UEX) and bimanual-experimental (BEX). There were no differences in the direction of preferences among the four conditions, but there were differences in the strength of lateralization. The strength of hand preference was higher in bimanual than in unimanual ones, and also in the experimental tasks than in the spontaneous ones. The use of tools and the type of grip also increased the strength of preferences, but had no effect on the direction of such preferences. We detected right-handedness at population-level for spontaneous bimanual actions, but not for the experimental ones. There was also a right asymmetry at the population level when considering all the tasks together. In this way, this was the first evidence that chimpanzees housed in an intermediate environment demonstrate right-handedness at population-level. In conclusion, chimpanzees exhibit a pattern of lateralization homologous to human beings, especially those actions that involve a complexity of execution (bimanual, tool use and precision grip) and that are most relevant for understanding the behavioral process of hominization of this trait in Homo sapiens.
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Walker, Kenneth N. (Kenneth Neal). "Differential Effects of Biofeedback Input on Lowering Frontalis Electromyographic Levels in Right and Left Handers." Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc331405/.
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This investigation was an attempt to replicate and expand previous research which suggested that laterality of electromyographic biofeedback input had a significant effect in lowering frontalis muscle activity. In 1984 Ginn and Harrell conducted a study in which they reported that subjects receiving left ear only audio biofeedback had significantly greater reductions in frontalis muscle activity than those receiving right ear only or both ear feedback. This study was limited to one biofeedback session and subjects were selected based on demonstration of right hand/ear dominance. The purpose of the present study was to determine whether the left ear effect reported by Ginn and Harrell could be replicated. Furthermore, the current investigation sought to extend the previous finding to left handed subjects and explore the stability of the effect, if found, by adding a second biofeedback session.
Subjects were 96 students recruited from undergraduate psychology classes. They were screened for handedness by the Edinburgh Handedness Inventory which resulted in identification of 48 right handers and 48 left handers. Subjects were randomly assigned to one of four groups consisting of left ear feedback, right ear feedback, both ears feedback, and controls. This resulted in eight conditions.
Analysis of variance of microvolt changes from baseline found no statistically significant differences between groups. An examination of the rank order of the data reveal a left ear group performance in the same direction as those reported by Ginn and Harrell (1984).
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Schmitz, Rémy. "Asymétries hémisphériques cérébrales dans la pseudonégligence, l'induction de faux souvenirs et l'apprentissage implicite: une approche cognitive et neuropsychologique." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209788.
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Petzold, Antje. "Lateralized Head Turning Bias in Humans – Cues to the Development of Human Cerebral Asymmetries." Bachelor's thesis, 2002. https://slub.qucosa.de/id/qucosa%3A629.
Full textAbstract:
The origin and development of human cerebral asymmetries is yet a debated issue. One prominent manifestation of cerebral asymmetry is handedness with humans showing a dextral population bias. Handedness in humans is not fully established before the age of six. However, head turning preference in newborns is thought to be an important factor in the development of later handedness. If this head turning preference did not disappear completely during development but would prevail into adulthood it might, thus, be associated with handedness. Therefore, this study aimed to assess head turning preference in adults and to relate a possibly emerging bias to handedness.
Forty-two adults (6 females, aged 23- 63, mean age = 35) participated in the study. Head turning preference was assessed by means of a move during Ju Jutsu martial arts training, which requires the trainee to move the head to either left or right. The direction of head movement is not specified for this move, leaving the choice to the trainee. Handedness was measured by the Edinburgh Handedness Inventory.
Results did not reveal a profound head turning bias in adults. Contrary to the dextral bias in handedness, in this study a leftward bias in head turning emerged from those participants who showed a head turning preference. Head turning bias did not depend on handedness.
The finding of a nearly absent and predominantly leftward head turning bias in this sample is discussed in the context of the Ju Jutsu task, training experience and trainer bias. It is concluded that the Ju Jutsu move is not a sufficient task to assess head turning preference in humans. Thus, to further illuminate the relation between head turning preference and handedness, studies are needed which assess head turning preference in adults in an un-trainable and unbiased situation.
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Lürken, Alexander [Verfasser]. "Funktionelle Asymmetrien und cerebrale Asymmetrien kortikaler Aktiviertheit / vorgelegt von: Alexander Lürken." 2004. http://d-nb.info/971725675/34.
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