Gotowa bibliografia na temat „Photorealistic Stimuli and Ecological Validity”

Subliminal stimuli can affect perception, decision-making, and action without being accessible to conscious awareness. Most evidence supporting this notion has been obtained in highly controlled laboratory conditions. Hence, its generalization to more realistic and ecologically valid contexts is unclear. Here, we investigate the impact of subliminal cues in an immersive navigation task using the so-called eXperience Induction Machine (XIM), a human accessible mixed-reality system. Subjects were asked to navigate through a maze at high speed. At irregular intervals, one group of subjects was exposed to subliminal aversive stimuli using the masking paradigm. We hypothesized that these stimuli would bias decision-making. Indeed, our results confirm this hypothesis and indicate that a subliminal channel of interaction exists between the user and the XIM. These results are relevant in our understanding of the bandwidth of communication that can be established between humans and their physical and social environment, thus opening up to new and powerful methods to interface humans and artefacts.

An important issue of psychological research is how experiments conducted in the laboratory or theories based on such experiments relate to human performance in daily life. Immersive virtual reality (VR) allows control over stimuli and conditions at increased ecological validity. The goal of the present study was to accomplish a transfer of traditional paradigms that assess attention and distraction to immersive VR. To further increase ecological validity we explored attentional effects with daily objects as stimuli instead of simple letters. Participants searched for a target among distractors on the countertop of a virtual kitchen. Target–distractor discriminability was varied and the displays were accompanied by a peripheral flanker that was congruent or incongruent to the target. Reaction time was slower when target–distractor discriminability was low and when flankers were incongruent. The results were replicated in a second experiment in which stimuli were presented on a computer screen in two dimensions. The study demonstrates the successful translation of traditional paradigms and manipulations into immersive VR and lays a foundation for future research on attention and distraction in VR. Further, we provide an outline for future studies that should use features of VR that are not available in traditional laboratory research.

Immersive Virtual Reality (IVR) is a simulated technology used to deliver multisensory information to people under different environmental conditions. When IVR is generally applied in urban planning and soundscape research, it reveals attractive possibilities for the assessment of urban sound environments with higher immersion for human participation. In virtual sound environments, various topics and measures are designed to collect subjective responses from participants under simulated laboratory conditions. Soundscape or noise assessment studies during virtual experiences adopt an evaluation approach similar to in situ methods. This paper aims to review the approaches that are utilized to assess the ecological validity of IVR for the perception of urban sound environments and the necessary technologies during audio–visual reproduction to establish a dynamic IVR experience that ensures ecological validity. The review shows that, through the use of laboratory tests including subjective response surveys, cognitive performance tests and physiological responses, the ecological validity of IVR can be assessed for the perception of urban sound environments. The reproduction system with head-tracking functions synchronizing spatial audio and visual stimuli (e.g., head-mounted displays (HMDs) with first-order Ambisonics (FOA)-tracked binaural playback) represents the prevailing trend to achieve high ecological validity. These studies potentially contribute to the outcomes of a normalized evaluation framework for subjective soundscape and noise assessments in virtual environments.

AbstractMany now consider “instinct” and “learning” opposite poles of a unidimensional continuum. An alternative model with two independently varying parameters predicts different selective pressures. Behavioral adaptation matches the organism's utilizations of stimuli and responses to their ecological validities: the mean validity over evolutionary time specifies the optimal initial potency of the prepared association; the variance specifies the optimal prepared plasticity.

Playing online games is gradually becoming mainstream entertainment, but some people may develop Internet gaming disorder (IGD). Like other behavioral addictive diseases, one of the main characteristics of IGD is a craving for games, which also makes people tend to approach game-related clues. Recently, a few researchers have started to use the approach–avoidance task (AAT) paradigm to study the approach bias of IGD, and they also think it is an essential characteristic of IGD. However, the traditional AAT cannot provide realistic approach–avoidance behavior to stimuli, and virtual reality has been proven to provide a highly ecological environment to measure approach bias. Therefore, this study innovatively integrates virtual reality and the AAT paradigm to measure the approach bias of IGD. We found that compared with neutral stimuli, IGD spent less time approaching game-related stimuli, which indicates that it is difficult for IGD to avoid game-related situations in the virtual environment. This study also revealed that game-related content stimuli in virtual reality alone did not increase the IGD group’s craving for games. These results proved that AAT in VR could cause the approach bias of IGD and provide high ecological validity and an effective tool for the intervention of IGD in the future.

The ever-growing body of soundscape research includes studies conducted both in everyday life environments and in laboratory settings. Yet, laboratory settings differ from in-situ and therefore may elicit different perceptions. The present study explores the ecological validity of soundscape reproduction in the laboratory using first-order Ambisonics and of different modes of questionnaire administration. Furthermore, it investigates the influence of the contextual factors of time of day, day of the week, and location on site on soundscape evaluations in situ and in the laboratory, based on the Swedish Soundscape Quality Protocol. We first tested measurement invariance between the computer-based and pen-and-paper administration of the soundscape questionnaire. We then investigated the influence of the above-mentioned contextual factors on soundscape evaluations, as well as the effect of stimuli selection in the laboratory. The analyses confirmed the underlying dimensions of proposed soundscape assessment questionnaires, confirmed metric invariance between computer and pen-and-paper, and revealed significant influences of time, day, and location on soundscape scales. This research represents a critical step in rigorously assessing soundscape evaluations in the laboratory and establishes solid evidence for the use of both in situ and laboratory soundscape studies.

Various experimental tasks suggest that fear guides attention. However, because these tasks often lack ecological validity, it is unclear to what extent results from these tasks can be generalized to real-life situations. In change detection tasks, a brief interruption of the visual input (i.e., a blank interval or a scene cut) often results in undetected changes in the scene. This setup resembles real-life viewing behavior and is used here to increase ecological validity of the attentional task without compromising control over the stimuli presented. Spider-fearful and nonfearful women detected schematic spiders and flowers that were added to one of two identical background pictures that alternated with a brief blank in between them (i.e., flicker paradigm). Results showed that spider-fearful women detected spiders (but not flowers) faster than did nonfearful women. Because spiders and flowers had similar low-level features, these findings suggest that fear guides attention on the basis of object features rather than simple low-level features.

ABSTRACTExplicit verbal comparisons in 53 popular children's books were syntactically and semantically classified. Comparison types found in these books were contrasted with comparisons used as comprehension stimuli in extant developmental research. Although noun-phrase metaphor has been a popular syntactic form in research, it is a rare form in children's literature. Implications for the design of future stimulus sets are discussed.

The majority of speech perception research investigates interpersonal perception through presentation of two types of stimuli: synthetic speech and/or natural speech. Synthetically created speech stimuli allows for precisely controlled manipulation of individual acoustic variables, but can sound unnatural calling into questions its ecological validity. Alternatively, natural speech preserves the full complement of redundant acoustic cues yet limits control of specific acoustic parameters. In this study, we investigate speech discrimination comparing perception of specified acoustic parameters (formant transition duration, F3 onset frequency, F3-F2 distance) across three types of speech stimuli: synthetic speech stimuli, natural speech of a standard adult speaker, and each participant’s own voice. We use the Wide Range Acoustic Accuracy Scale (WRAAS), a computer-based perceptual assessment that uses a parameter estimation by sequential testing (PEST) adaptive-tracking algorithm to rapidly identify a listener’s ability to discriminate sounds. Most trials are presented near the Just-Noticeable-Difference (JND) of a stimulus continuum; thus, few trials are “wasted” with obviously same or different sounds. This study of typical adult listeners (n = 20, enrollment is ongoing) will provide baseline data for future work investigating perception of these same stimuli in children.

La capacité à estimer rapidement le nombre d'éléments dans une scène sans compter explicitement a fait l'objet de nombreuses recherches.Les études expérimentales et les modèles computationnels ont cherché à révéler les mécanismes permettant au cerveau humain de percevoir la numérosité d'un seul coup d'œil. Les récentes avancées en imagerie, incluant l'IRM fonctionnelle, l'analyse multivariée et la modélisation du champ récepteur des neurones, ont permis d'en apprendre davantage sur la manière dont l'information numérique est encodée dans le cerveau. En particulier, ces travaux ont mis en lumière le rôle de régions telles que les cortex frontal et pariétal dans la perception numérique. Malgré ces avancées, la recherche sur la perception de la numérosité a souvent reposé sur des stimuli visuels simplifiés. Bien que pratiques, ces stimuli ne reflètent pas la complexité des environnements visuels réels et négligent souvent l'impact de leurs statistiques non numériques, qui covarient pourtant avec la numérosité. Cette dépendance soulève des questions sur la validité écologique des résultats actuels et questionne si la numérosité est une propriété perçue directement ou inférée à partir d'autres caractéristiques visuelles. Les mécanismes sous-jacents à la perception visuelle de la numérosité restent donc une question ouverte. Dans cette thèse, nous avons développé un ensemble de stimuli synthétiques photoréalistes afin de pallier ces limites. Ces stimuli présentent une grande variabilité visuelles tout en permettant un contrôle expérimental précis. Ce jeu de données permet d'étudier la perception de la numérosité dans des contextes plus proches des images naturelles. À l'aide de ces stimuli photoréalistes, constitués d'objets 3D intégrés dans des scènes variées, nos analyses ont montré que les réseaux de neurones convolutifs profonds (CNN) optimisés pour la reconnaissance d'objets peuvent encoder des informations numériques dans divers contextes. À l'inverse, les réseaux non entraînés ne parviennent pas à discriminer le contenu numérique, se limitant à encoder des statistiques visuelles de bas niveau. Ces résultats indiquent que les modèles non entraînés sont inadaptés pour comprendre notre capacité à extraire le contenu numérique d'une scène et soulignent l'importance d'utiliser des stimuli complexes pour étudier la représentation de la numérosité. Étant donné le rôle des CNN en tant que modèles de la voie visuelle ventrale, nous avons ensuite exploré la représentation numérique au-delà des régions dorsales traditionnelles. Ainsi, nous avons enregistré l'activité cérébrale de participants portant leur attention sur le contenu numérique de nos stimuli visuels photoréalistes. Ce paradigme expérimental a permis de dissocier l'information numérique des statistiques visuelles corrélées, et ainsi d'examiner leurs contributions distinctes. Nos résultats ont révélé que les zones occipito-latérales, souvent associées à la reconnaissance d'objets, peuvent traiter simultanément des informations numériques et liées aux objets. De plus, les régions pariétales ont démontré un rôle spécialisé dans l'encodage de l'information numérique. En revanche, les statistiques visuelles de bas niveau influencent principalement les régions visuelles primaires et ventrales temporales, avec un impact minimal sur les régions dorsales supérieures. Ces résultats soulignent l'existence d'une organisation hiérarchique dans le traitement visuel, avec une progression de l'encodage de caractéristiques élémentaires à la représentation abstraite d'objets et de la numérosité dans les régions avancées du cerveau. Nos travaux mettent en lumière la nature abstraite de la représentation de la numérosité et approfondissent ainsi notre compréhension de la cognition numérique dans des environnements visuels réalistes. Ils soulignent également l'importance d'utiliser des stimuli complexes pour découvrir les mécanismes sous-jacents à l'extraction de la numérosité dans le cerveau
The ability to rapidly estimate the number of items in a scene without explicit counting, known as visual number sense, has been the focus of extensive research. Experimental studies and computational models have sought to uncover the mechanisms that enable the human brain to extract numerosity at a glance. Recent advances in imaging techniques, including ultra-high-field functional MRI (fMRI), multivariate pattern analysis, and population receptive field (pRF) modeling, have provided deeper insights into how numerical information is encoded in the brain.These studies have highlighted the involvement of higher-order regions, such as the frontal and parietal cortices, but also lower-level areas, in numerical perception. Most research on numerosity perception has relied on simplified visual stimuli, such as binary dot arrays. While useful, these stimuli fail to capture the complexity of real-world visual environments and present a special case where numerosity is tightly correlated with some low-level statistics of the visual input. This raises questions about ecological validity, and about the extent to which previous findings reflected the discrete number of items per se as opposed to correlated low-level factors. In this thesis, we developed a synthetic photorealistic stimulus dataset to address these limitations, introducing high variability in the characteristics of both objects and scenes while maintaining precise experimental control. This dataset allows for the study of numerosity perception in contexts closer to natural images. Using this new dataset of photorealistic renderings of 3D objects embedded in diverse background scenes, our analyses demonstrated that deep convolutional neural networks (CNNs) optimized for object recognition could encode numerical information with robustness to diverse objects and scenes in distributed activity patterns of their higher convolutional layers. Conversely, untrained networks failed to discriminate numerical content across changes in those other high-level visual properties and mainly encoded low-level summary statistics.These findings suggest that untrained models may not truly encode discrete numerosity and emphasize the importance of using complex stimuli to probe the neural mechanisms of visual number sense. Given the role of CNNs' as models of the ventral visual stream, this research motivates further investigation of how numerical information is represented in the brain beyond commonly studied dorsal-parietal areas. Therefore, in an independent 7T fMRI study, we recorded brain activity of both ventral and dorsal visual pathways while participants viewed and attended to the numerical content of similar synthetic photorealistic stimuli.This experimental paradigm enabled us to disentangle numerical information from correlated visual statistics, allowing for the examination of their distinct contributions to brain activity. Our findings revealed that lateral occipital areas, commonly linked to object recognition, could simultaneously represent numerical and object-related information. Additionally, dorsal parietal regions demonstrated a specialized role in encoding numerical information beyond basic visual features. In contrast, low-level visual statistics primarily influenced early visual and higher-level ventral temporal areas, with minimal impact on higher-order dorsal regions. These findings illustrate a hierarchical organization in visual processing, transitioning from encoding of low-level features to more invariant representations of objects and numerosity in higher-level brain areas. Our work underscores the abstract nature of numerosity representations, advancing our understanding of numerical cognition under more realistic visual conditions

Le craving est considéré comme une composante centrale de l’addiction, potentiellement impliquée dans les processus de rechute, et influencée par de nombreux facteurs. Les études ayant examiné le lien entre craving et rechute montrent cependant des résultats contradictoires. Ces divergences pourraient s’expliquer par les limites méthodologiques rencontrées pour évaluer le craving de façon rétrospective ou pour l’induire expérimentalement en laboratoire. La méthode EMA (Ecological Momentary Assessment) utilise des technologies mobiles afin d’évaluer les sujets dans leur environnement naturel et de récolter des données en temps réel. Cette approche est particulièrement intéressante pour étudier les fluctuations rapides du craving, capturer l’influence des variables environnementales, ainsi que pour examiner le lien prospectif entre plusieurs variables. L’objectif général de cette thèse était d’utiliser la méthode EMA afin d’examiner en vie quotidienne le craving, ses modérateurs, et son lien avec l’usage de substances chez des sujets dépendants débutant une prise en charge pour une addiction à une substance. L’analyse de la littérature révèle que la majorité des études EMA examinant le craving concerne le tabac et l’alcool, et que peu d’études ont examiné ce phénomène pour des substances illégales. La partie expérimentale de cette thèse a permis de 1) démontrer la faisabilité et la validité de la méthode EMA chez des sujets dépendants, quelle que soit la substance de dépendance (tabac, alcool, cannabis ou opiacés), 2) montrer un lien prospectif unidirectionnel entre l’intensité du craving et l’usage de substances pour les 4 groupes de substances, et 3) mettre en évidence une augmentation du craving face à des stimuli conditionnés (cues) rencontrés en vie quotidienne, augmentation d’autant plus importante qu’il s’agissait de cues individuels (personnels à chaque sujet). Cette étude démontre l’intérêt de la méthode EMA dans l’étude des addictions, souligne le rôle du craving dans les processus de rechute, et encourage le développement de protocoles d’extinction de la réactivité aux cues centrés sur des cues individuels propres à chaque sujet
Craving is a central component of addiction, involved in relapse process and under the influence of many factors. However, studies examining the link between craving and relapse have revealed some contradictory results. These inconsistencies could be due to limits encountered to assess craving in laboratory or clinical settings. Ecological Momentary Assessment (EMA) methods use mobile technologies to assess subjects in their daily life, and collect data in real time. EMA is particularly well suited to assess fluctuations of craving, capture influence of environmental moderators, and examine prospective link between variables. The objective of this thesis was to use EMA to examine craving, its moderators, and its link with substance use in daily life among substance-dependent outpatients evaluated at treatment intake. Review of the literature revealed that majority of EMA studies examining craving concerned tobacco and alcohol, but only few examined illegal substances. The experimental part of this thesis 1) demonstrated that EMA methods are feasible and provide valid data in individuals with dependence for different types of substances (tobacco, alcohol, cannabis, opiates), 2) showed a prospective unidirectional association between craving and subsequent substance use in the 4 groups of substances, and 3) confirmed that conditioned stimuli (cues) encountered in daily life are associated with an increase of craving intensity, and showed that individual personalized cues elicit a more robust effect on craving compared to standard cues. These results highlight the relevance of using EMA methods to study addiction, suggest that craving has a key place in the relapse process, and encourage to develop tailorised extinction protocols centered on individual cues rather than standard non-specific cues

External validity is the extent to which the findings of an experimental study are applicable or can be generalized to other people and contexts. External validity includes both population validity (i.e., the representativeness of the sample) and ecological validity (i.e., the representativeness of other contextual variables such as the stimuli, workflow, and environment). There is no consensus on the number and names of the ecological validity dimensions researchers should consider when designing or evaluating usability evaluations in health care. Therefore, in this paper, we integrated concepts from 3 ecological validity frameworks into a unified external validity. We used this new framework to describe the dimensions of external validity of a previous usability study. This framework can inform the design and description of usability evaluations to enhance reproducibility and comparison of findings and ultimately better understand the impact of different dimensions and external validity holistically.

Given the prevalence of traumatic brain injury (TBI), and the fact that many mild TBIs have no external marker of injury, there is a pressing need for innovative assessment technology. The demand for assessment that goes beyond traditional paper-and-pencil testing has resulted in the use of automated cognitive testing for increased precision and efficiency; and the use of virtual environment technology for enhanced ecological validity and increased function-based assessment. To address these issues, a Virtual Reality Stroop Task (VRST) that involves the subject being immersed in a virtual Humvee as Stroop stimuli appear on the windshield was developed. This study is an initial validation of the VRST as an assessment of neurocognitive functioning. When compared to the paper-and-pencil, as well as Automated Neuropsychological Assessment Metrics versions of the Stroop, the VRST appears to have enhanced capacity for providing an indication of a participant's reaction time and ability to inhibit a prepotent response while immersed in a military relevant simulation that presents psychophysiologically arousing high and low threat stimuli.

Abstract Taking its cue from replacement and constitution hypotheses (Chapter 5), this chapter highlights the cognitive significance of embodied religious practices and religious material culture. It applies dozens of specific empirical findings from embodied cognition research to Christian Eucharistic practices, among other examples. Studies should be treated with caution given methodological issues identified in experimental psychology, including replication, small or unrepresentative samples, and ecological validity. Nevertheless, these findings illuminate how bodily postures and movements, ritual objects, pilgrimage routes, visual culture, multisensory stimuli, and social interactions serve as cognitive scaffolding by supporting numerous aspects of cognition including memory, emotion, attention, judgement, and conceptualisation. Although such mechanisms are most readily identified with elaborate liturgical practices, I draw upon ethnographic accounts to argue that they are also relevant to ‘non-liturgical’ traditions.

Background: There is only one instrument to assess functionality directly to the patients in Brazil (Directed Assessment Functional Status revised). However, this instrument is impractical for fast, outpatient and hospital contexts. We need to count with a brief and direct assessment of functionality due to the increasement of elders living alone. Objective: To develop and validate a screening test of direct functionality in healthy older adults. Method: The creation of the cognitive functionality instrument it was made carried out based on the literature review of the existing tests, ecological instruments, scales to assess functionality. We created 7 ecological tasks to evaluate the performance of daily complex activities with the patient. The tasks involve orientation, shopping skills, memorization, information recognition, planning and, problem solving. Results: The pilot version have twice as many stimuli than those of the final version. To study face and conceptual validity of the new instrument, we recruit 8 expert judges (2 neurologists, 2 neuropsychologists, 2 speech therapists, 2 occupational therapists) and they had 96.5% agreement. Conclusions: The task with the least agreement was the planning and problem solving. The next steps will be to evaluate convergent validity and internal consistency. The new instrument is expected to help assess the functionality of older adults mainly in contexts that requests a brief and fast evaluation and with elders who live alone. Keywords: functionality, elderly, instrument, development.