Are Face and Object Recognition Independent? A Neurocomputational Modeling Exploration

Are face and object recognition abilities independent? Although it is commonly believed that they are, Gauthier et al.(2014) recently showed that these abilities become more correlated as experience with nonface categories increases. They argued that there is a single underlying visual ability, v, that is expressed in performance with both face and nonface categories as experience grows. Using the Cambridge Face Memory Test and the Vanderbilt Expertise Test, they showed that the shared variance between Cambridge Face Memory Test and Vanderbilt Expertise Test performance increases monotonically as experience increases. Here, we address why a shared resource across different visual domains does not lead to competition and to an inverse correlation in abilities? We explain this conundrum using our neurocomputational model of face and object processing (The Model, TM). Our results show that, as in the behavioral data, the correlation between subordinate level face and object recognition accuracy increases as experience grows. We suggest that different domains do not compete for resources because the relevant features are shared between faces and objects. The essential power of experience is to generate a "spreading transform" for faces that generalizes to objects that must be individuated. Interestingly, when the task of the network is basic level categorization, no increase in the correlation between domains is observed. Hence, our model predicts that it is the type of experience that matters and that the source of the correlation is in the fusiform face area, rather than in cortical areas that subserve basic level categorization. This result is consistent with our previous modeling elucidating why the FFA is recruited for novel domains of expertise (Tong et al., 2008)

Visual appearance interacts with conceptual knowledge in object recognition

Objects contain rich visual and conceptual information, but do these two types of information interact? Here, we examine whether visual and conceptual information interact when observers see novel objects for the first time. We then address how this interaction influences the acquisition of perceptual expertise. We used two types of novel objects (Greebles), designed to resemble either animals or tools, and two lists of words, which described non-visual attributes of people or man-made objects. Participants first judged if a word was more suitable for describing people or objects while ignoring a task-irrelevant image, and showed faster responses if the words and the unfamiliar objects were congruent in terms of animacy (e.g., animal-like objects with words that described human). Participants then learned to associate objects and words that were either congruent or not in animacy, before receiving expertise training to rapidly individuate the objects. Congruent pairing of visual and conceptual information facilitated observers' ability to become a perceptual expert, as revealed in a matching task that required visual identification at the basic or subordinate levels. Taken together, these findings show that visual and conceptual information interact at multiple levels in object recognition

Le processus de rétablissement de personnes qui ont développé un trouble mental après avoir été victimes de crimes violents

Chaque année au Québec, les crimes violents touchent 1 personne sur 20, la majorité des victimes étant des femmes. Ces crimes ont des conséquences importantes. Ils sont associés à de l’évitement, de la méfiance, à la difficulté à refaire confiance à autrui, ainsi qu’à un plus grand risque de développer un trouble mental (Norris et Kanisasty, 1994; Organisation mondiale de la santé [OMS], 2013). Plusieurs facteurs pourraient influencer le parcours de rétablissement de ces victimes. Le soutien social et la résilience ont été identifiés comme étant des facteurs clés aidant au rétablissement de personnes ayant des troubles mentaux (Caron et Guay, 2005; Duplantier, 2011), mais peu d’études ont posé un regard sur le rétablissement des personnes victimes de crimes violents ayant développé des troubles mentaux et encore moins sur le soutien social qu’elles ont exprimé avoir reçu. Cette recherche a ainsi pour objectif de documenter le processus de rétablissement des personnes victimes de crimes violents qui ont développé un trouble mental. Plus particulièrement, elle mettra en lumière la contribution du soutien social et de la résilience dans ce processus. Afin de répondre aux objectifs de l’étude, un devis descriptif mixte, avec une majeure qualitative, a été privilégié. Au total, huit personnes, dont 7 femmes et 1 homme dont l’âge moyen est de 44 ans (ET=12,47) ont accepté de participer à l’étude. La majorité de ces participantes ont été volontairement recrutées dans un Centre d’aide pour les victimes d’actes criminels (CAVAC). Afin d’explorer et de documenter les parcours de rétablissement des participantes, une entrevue semi-dirigée a été réalisée et trois questionnaires auto-rapportés ont été administrés. L’analyse des données qualitatives et quantitatives indique que les participantes de l’étude ont cheminé dans le rétablissement de leur trouble mental et que des personnes significatives présentes au sein de leur réseau social les ont aidées à se sentir considérées, reconnues et valorisées. Enfin, le soutien offert par les ressources d’aide, notamment celles du système judiciaire, a parfois aidé et a d’autres fois nui à leur rétablissement. La revictimisation, la lourdeur du système de justice ainsi que le soutien offert par la famille ont été les principaux facteurs identifiés par les répondantes comme n’ayant pas su répondre à leurs besoins. Pour les participantes pour qui le soutien social semble avoir le moins contribué à leur cheminement, la capacité de résilience a été un facteur clé qui leur a permis de limiter l’effet du crime subi sur leur bien-être. Ces résultats doivent être interprétés en considérant les limites et forces de cette étude. Le petit échantillon de participantes1 volontaires (n = 8), recrutées au sein d’un seul milieu, témoigne d’une réalité restreinte qui pourrait s’avérer biaisée, notamment en raison de la non atteinte de la saturation empirique des données. Malgré cette limite, cette étude présente des forces notamment quant aux retombées pour la recherche et la pratique. Elle soulève l’importance de la qualité des liens sociaux pour soutenir les personnes victimes de crimes violents dans leur rétablissement. Un réseau de soutien social optimisé par des interventions pourrait faciliter le rétablissement et aider à renforcer le sentiment de protection fragilisé par les violences vécues. Développer des interventions favorisant la capacité de résilience pourrait aussi être un facteur clé prédisposant les victimes à pouvoir compter sur l’autre de nouveau

Mere Exposure Alters Category Learning of Novel Objects

We investigated how mere exposure to complex objects with correlated or uncorrelated object features affects later category learning of new objects not seen during exposure. Correlations among pre-exposed object dimensions influenced later category learning. Unlike other published studies, the collection of pre-exposed objects provided no information regarding the categories to be learned, ruling out unsupervised or incidental category learning during pre-exposure. Instead, results are interpreted with respect to statistical learning mechanisms, providing one of the first demonstrations of how statistical learning can influence visual object learning

Evaluating assumptions of scales for subjective assessment of thermal environments – Do laypersons perceive them the way, we researchers believe?

International audienc

The impact of real-time carbon dioxide awareness on occupant behavior and ventilation rates in student dwellings

Although existing standards typically prescribe fixed ventilation rates, a large portion of the building stock lacks mechanical ventilation systems. Such buildings obtain outdoor air through unintentional infiltration, open windows, and the operation of exhaust fans, which are mainly dependent on user awareness and behavior. This study investigates whether the presence of a simple CO$_2$ meter display can alter user behavior and improve indoor air quality (IAQ) in dwellings. We conducted a two-week monitoring of CO$_2$concentration, air temperature, and relative humidity in 60 student dwellings (bedrooms and living rooms) in Denmark and Switzerland. During the first week, the CO$_2$ display was concealed, and occupants adhered to their usual routines. In the second week, occupants used the display\u27s visual feedback to enhance IAQ when necessary. Results revealed that over 95% of dwellings witnessed a reduction in median CO$_2$ levels during the second week, both overall and in individual rooms. Furthermore, a descriptive analysis of CO$_2$ concentration step changes exceeding the thresholds of “normal variation” showed an increase in the number of negative step changes, indicating a shift in user behavior. These findings underscore the efficacy ofa display interface providing information on the indoor environment in triggering behavior changes and improving IAQ in dwellings

Beyond Shape: How You Learn about Objects Affects How They Are Represented in Visual Cortex

Background: Experience can alter how objects are represented in the visual cortex. But experience can take different forms. It is unknown whether the kind of visual experience systematically alters the nature of visual cortical object representations. Methodology/Principal Findings: We take advantage of different training regimens found to produce qualitatively different types of perceptual expertise behaviorally in order to contrast the neural changes that follow different kinds of visual experience with the same objects. Two groups of participants went through training regimens that required either subordinate-level individuation or basic-level categorization of a set of novel, artificial objects, called ‘‘Ziggerins’’. fMRI activity of a region in the right fusiform gyrus increased after individuation training and was correlated with the magnitude of configural processing of the Ziggerins observed behaviorally. In contrast, categorization training caused distributed changes, with increased activity in the medial portion of the ventral occipito-temporal cortex relative to more lateral areas. Conclusions/Significance: Our results demonstrate that the kind of experience with a category of objects can systematically influence how those objects are represented in visual cortex. The demands of prior learning experience therefore appear t

Category-Specific Responses to Faces and Objects in Primate Auditory Cortex

Auditory and visual signals often occur together, and the two sensory channels are known to influence each other to facilitate perception. The neural basis of this integration is not well understood, although other forms of multisensory influences have been shown to occur at surprisingly early stages of processing in cortex. Primary visual cortex neurons can show frequency-tuning to auditory stimuli, and auditory cortex responds selectively to certain somatosensory stimuli, supporting the possibility that complex visual signals may modulate early stages of auditory processing. To elucidate which auditory regions, if any, are responsive to complex visual stimuli, we recorded from auditory cortex and the superior temporal sulcus while presenting visual stimuli consisting of various objects, neutral faces, and facial expressions generated during vocalization. Both objects and conspecific faces elicited robust field potential responses in auditory cortex sites, but the responses varied by category: both neutral and vocalizing faces had a highly consistent negative component (N100) followed by a broader positive component (P180) whereas object responses were more variable in time and shape, but could be discriminated consistently from the responses to faces. The face response did not vary within the face category, i.e., for expressive vs. neutral face stimuli. The presence of responses for both objects and neutral faces suggests that auditory cortex receives highly informative visual input that is not restricted to those stimuli associated with auditory components. These results reveal selectivity for complex visual stimuli in a brain region conventionally described as non-visual “unisensory” cortex

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe