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International audience

This study is part of a larger attempt to explore how the brain produces conscious experience. Our main objective here was to take advantage of a neural signature conveyed by the steady-state visual evoked potentials (SSVEP) technique (1) to explore the extent to which complex visual images can be processed in the absence of consciousness and (2) to determine whether this tool can be used to shed light on participants’ phenomenal experience of these images. To this end, we embedded faces within sequences of non-face stimuli and manipulated their contrast to create a subliminal condition. Our results were threefold. First, we show that a significant brain activation can be delineated with the SSVEP tool even when participants report being unable to see the stimuli. In this subliminal condition, the brain response was confined to the back of the scalp. Second, we observe that the face signal increases in magnitude and propagates bilaterally along a posterior-to-anterior axis as image contrast increases. Third, we suggest that SSVEP could be used as a novel instance of a no-report paradigm because it requires no overt behavioural response, and because at some contrast levels and electrodes, its outputs (signal magnitude and scalp topography) predict people’s self-reported phenomenal experience.

International audience; Adoptant la forme épistolaire, ce portrait offre une vision d’un être aussi ordinaire qu’exceptionnel. En revenant sur le parcours d’une femme dalit, Alexandra de Heering s’efforce de dépeindre à l’aide de témoignages et d’images prises sur le vif, la vie de celle qu’elle a rencontrée il y a presque dix ans dans un village du sud de l’Inde. Jothi, comme beaucoup d’autres mais pas tout à fait comme tout le monde, a fait le choix d’affronter les vicissitudes de la vie à bras-le-corps et, sans entrer dans le militantisme politique à proprement parler, a œuvré pour défendre sa dignité et celle de sa communauté, tiraillée entre le désir d’émancipation et la peur des représailles.

International audience

International audience

Is a short and transient period of visual deprivation early in life sufficient to induce lifelong changes in how we attend to, and integrate, simple visual and auditory information [1, 2]? This question is of crucial importance given the recent demonstration in both animals and humans that a period of blindness early in life permanently affects the brain networks dedicated to visual, auditory, and multisensory processing [1-16]. To address this issue, we compared a group of adults who had been treated for congenital bilateral cataracts during early infancy with a group of normally sighted controls on a task requiring simple detection of lateralized visual and auditory targets, presented alone or in combination. Redundancy gains obtained from the audiovisual conditions were similar between groups and surpassed the reaction time distribution predicted by Miller's race model. However, in comparison to controls, cataract-reversal patients were faster at processing simple auditory targets and showed differences in how they shifted attention across modalities. Specifically, they were faster at switching attention from visual to auditory inputs than in the reverse situation, while an opposite pattern was observed for controls. Overall, these results reveal that the absence of visual input during the first months of life does not prevent the development of audiovisual integration but enhances the salience of simple auditory inputs, leading to a different crossmodal distribution of attentional resources between auditory and visual stimuli.

International audience

International audience; This presentation will address the evolution of the visual rhetoric of Tamil commercial 'ordinary' portrait photography meant for private use, from the end of the 19th century till 1980’s. As a historian, I consider these photographs as traces of an evolving visual culture as well as historical sources providing important information on several aspects of Tamil cultural and social history. In order to provide a concrete tool for the study of Tamil photo portraiture conventions (in other words of what is considered to be a good portrait over the years), I will present a chronologically organised typology of the different visual modes of representation in these portraits. The typology will be based on a careful examination of some objective and visible dimensions in the portraits which progressively get rid of the colonial habitus. This will constitute a basis on which to elaborate a more detailed dating of the photos. The conventions of representation and the symbolic choices are not inconsequential. They are the result of aesthetic and ethical choices, but also of sociological concerns, technical constraints and historical context, which we will introduce. This work is based on the analysis of a set of more than 4000 pictures drawn from a new archive dealing specifically with South Indian portrait photography (STARS Archive).

Horizontal information is crucial to face processing in adults. Yet the ontogeny of this preferential type of processing remains unknown. To clarify this issue, we tested 3-month-old infants' sensitivity to horizontal information within faces. Specifically, infants were exposed to the simultaneous presentation of a face and a car presented in upright or inverted orientation while their looking behavior was recorded. Face and car images were either broadband (UNF) or filtered to only reveal horizontal (H), vertical (V) or this combined information (HV). As expected, infants looked longer at upright faces than at upright cars, but critically, only when horizontal information was preserved in the stimulus (UNF, HV, H). These results first indicate that horizontal information already drives upright face processing at 3 months of age. They also recall the importance, for infants, of some facial features, arranged in a top-heavy configuration, particularly revealed by this band of information. © 2016 Wiley Periodicals, Inc. Dev Psychobiol 58: 536-542, 2016.

Across cultures and languages, people find similarities between the products of different senses in mysterious ways. By studying what is called cross-modal correspondences, cognitive psychologists discovered that lemons are fast rather than slow, boulders are sour, and red is heavier than yellow. Are these cross-modal correspondences established via sensory perception or can they be learned merely through language? We contribute to this debate by demonstrating that early blind people who lack the perceptual experience of color also think that red is heavier than yellow but to a lesser extent than sighted do., SCOPUS: ar.j, info:eu-repo/semantics/published

International audience

International audience; Speak, Memory. Oral Histories of Kodaikanal Dalits is the outcome of a research based on Dalit oral narratives, to record and to understand their interpretation of their own pasts. To reveal the richness and complexity of this through the words and rhythms of Cakkiliyar testimonies is the formative concern of this book. It seeks to understand, historically, the phenomenon of untouchability as it was experienced, internalised and articulated by Dalits. By shedding light on ceri life in the past and opening a window on to the present, this study attempts to enhance our understanding of the dynamics of social change amongst Dalits at the village level. Hence, it aims to provide a biography of these localities. Testimonies and the memories they involve enable us to delve into the perceptions of the past and the different ways of speaking about it, within the same community.

Mirror invariance refers to a predisposition of humans, including infants and animals, which urge them to consider mirrored images as corresponding to the same object. Yet in order to learn to read a written system that incorporates mirrored letters (e.g., vs. in the Latin alphabet), humans learn to break this perceptual bias. Here we examined the role visual experience and input modality play in the emergence of this bias. To this end, we tested congenital blind (CB) participants in two same-different tactile comparison tasks including pairs of mirrored and non-mirrored Braille letters as well as embossed unfamiliar geometric shapes and Latin letters, and compared their results to those of age-matched sighted participants involved in similar but visually-presented tasks. Sighted participants showed a classical pattern of results for their material of expertise, Latin letters. CB's results signed for their expertise with the Braille script compared to the other two materials that they processed according to an internal frame of reference. They also evidenced that they automatically break mirror invariance for different materials explored through the tactile modality, including Braille letters. Altogether, these results demonstrate that learning to read Braille through the tactile modality allows breaking mirror invariance in a comparable way to what is observed in sighted individuals for the mirrored letters of the Latin alphabet.

Children take many years to become as skilled as adults in differentiating among 5 faces and there is debate about the role of face experience in improving their skills. Here we tested whether the increase in exposure to the faces of children associated with entering school leads to improved face discrimination for this face category. To do so, we compared the face discrimination abilities of 3- to 4-year-old children who began attending school for the first time with those of 10 age-matched controls not yet in school. Both groups completed a 2-alternative forced-choice matching task with adult and child faces, presented both in an upright and inverted orientation, at Time 1 (within the first month of entering school for the school group) and at Time 2 (5 months later). Between Time 1 and Time 2, both groups improved in discriminating between adult faces, but only the preschoolers 15 improved for child faces. These effects were not modulated by inversion. Overall, these results suggest that, during the preschool years, a natural increase in exposure to the faces of 1 face category leads to improved discrimination of novel exemplars of this face category.

L’historiographie indienne est longtemps restee silencieuse sur l’histoire des intouchables, ou des Dalits comme on s’y refere generalement aujourd’hui (ce terme, qui signifie l’opprime en marathi, est aujourd’hui prefere aux nombreux autres qui l’ont precede car il traduit correctement le caractere force de leur assujettissement). Ce n’est qu’au debut des annees 1980, suite a l’emergence des etudes subalternistes, et en parallele au developpement d’un mouvement dalit a travers le pays, que d...

Presentation de Joies et peines de l’enfant Naktsang En 2007 paraissait en Republique populaire Chine (RPC) un ouvrage insolite, intitule Joies et peines de l’enfant Naktsang. L’auteur, un fonctionnaire tibetain a la retraite nomme Naktsang Nulo, avec le regard du jeune garcon qu’il etait alors, y raconte en detail l’histoire des annees 1950 telle qu’il l’a vecue, depouillee de toute appreciation retrospective. Le recit comptait parmi les toutes premieres publications a evoquer cette periode ...

Brief report; International audience; Horizontal information is crucial to face processing in adults. Yet the ontogeny of this preferential type of processing remains unknown. To clarify this issue, we tested 3-month-old infants' sensitivity to horizontal information within faces. Specifically, infants were exposed to the simultaneous presentation of a face and a car presented in upright or inverted orientation while their looking behavior was recorded. Face and car images were either broadband (UNF) or filtered to only reveal horizontal (H), vertical (V) or this combined information (HV). As expected, infants looked longer at upright faces than at upright cars, but critically, only when horizontal information was preserved in the stimulus (UNF, HV, H). These results first indicate that horizontal information already drives upright face processing at 3 months of age. They also recall the importance, for infants, of some facial features, arranged in a top-heavy configuration, particularly revealed by this band of information.

Patients treated for bilateral congenital cataract are later impaired on several hallmarks of adults' expertise with upright faces but report no problem with remembering faces. Here, we provide the first formal data on their face memory. We compared 12 adults with a history of visual deprivation from bilateral congenital cataracts to 24 age-matched controls with normal vision on their ability to recognize famous and recently learned faces, and on their subjective impression of their face memory. Bilateral congenital cataract patients demonstrated a prosopagnosic-like deficit, being slower and less accurate in recognizing both famous faces and recently learned faces, despite not differing on most questions about their impression of their face memory. Patients' results on three perceptual tasks (the composite face effect, the Benton test of recognizing faces through a change in point of view, and the Jane test of sensitivity to feature spacing) were also not correlated with their face memory deficits. These results suggest that early visual input is necessary not only for perceptual expertise in differentiating among unfamiliar upright faces, but also for normal accuracy in remembering the identity of individual faces. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 56: 96-108, 2014.

Faces are adaptively coded relative to visual norms that are updated by experience, and this adaptive coding is linked to face recognition ability. Here we investigated whether adaptive coding of faces is disrupted in individuals (adolescents and adults) who experience face recognition difficulties following visual deprivation from congenital cataracts in infancy. We measured adaptive coding using face identity aftereffects, where smaller aftereffects indicate less adaptive updating of face-coding mechanisms by experience. We also examined whether the aftereffects increase with adaptor identity strength, consistent with norm-based coding of identity, as in typical populations, or whether they show a different pattern indicating some more fundamental disruption of face-coding mechanisms. Cataract-reversal patients showed significantly smaller face identity aftereffects than did controls (Experiments 1 and 2). However, their aftereffects increased significantly with adaptor strength, consistent with norm-based coding (Experiment 2). Thus we found reduced adaptability but no fundamental disruption of norm-based face-coding mechanisms in cataract-reversal patients. Our results suggest that early visual experience is important for the normal development of adaptive face-coding mechanisms.

This paper explores the various ways Cakkiliyar people, a Dalit community, relate, through memory, to their past and their history. Far from constituting a homogeneous group, the more than 60 testimonies collected among Cakkiliyars reveal a diversity of perspectives on the past, strongly influenced by the situation in the present and aspirations for the future. Three distinct ways of thinking and three prototypes emerge from the testimonies; each one is defined by a specific way of positioning oneself in relation to various historical times.