A number of recent studies on early categorization suggest that young infants form category representations for stimuli at both global and basic levels of exclusiveness (i.e., mammal, cat). A set of computational models designed to analyze the factors responsible for the emergence of these representations are presented. The models (1) simulated the formation of global-level and basic-level representations, (2) yielded a global-to-basic order of category emergence and (3) revealed the formation of two distinct global-level representations - an initial "self-organizing' perceptual global level and a subsequently "trained" arbitrary (i.e., non-perceptual) global level. Information from the models is used to make a number of testable predictions concerning category development in infants.

It is known that affective touch leads to broad cortical activations including posterior STS, key region of the so-cial brain. Our goal is to discover if a similar pattern of activation can be observed in 5-months-old infants, or whether thedevelopment of this cortical specialization results from extensive postnatal experience.Over two studies we used functional-Near-InfraRed-Spectroscopy (fNIRS) to compare social touch (a human caress) tonon-social touch (a caress performed with a spoon in study1 -n=22- or with an electric toothbrush in study2 -n=17-).In study1 we found similar patterns of activation to the social and non-social stimulus. In study2 we report broad responsesto the non-social stimulus, but, to our surprise, we found no activations to the human caress.In light of these results we conclude that it is possible that at this age discrimination between social and non-social touch inthe posterior temporal lobe is still undergoing specialization.

Caregiver-infant interaction through touch was shown to have long-term effects on child’s cognitive development,but the mechanisms are poorly understood. Our aim is to investigate how affective touch (slow gentle caressing) affects arousalstates in young infants. Previous work showed that slow-touch decreases heart rate in 9-month-old infants.We tested two groups of 6-months-old (n=26) and 9-months-old infants (n=23). We measured heart rate and saccadic reactiontime while infants performed a visual orienting task, where speed of re-orienting from a central fixation to a peripheral targetwas measured. During the experiment, infants received either slow or fast-touch on their back in blocked trials. We found noeffects of touch on heart rate in either age-group, and only marginal effects of slow-touch on reaction times in 9-month-oldinfants. We are currently testing 2 months-old infants to investigate if these effects are observed earlier in life; these new resultswill be discussed.

Atypicalities in sensory perception are observed in individuals diagnosed with ASD and ADHD but have rarely beencontrasted in experimental studies. In the visual domain, superior performance on visual search tasks and hypersensitivity toflickering lights have been cited as evidence of unusual sensory profiles.To measure a reliable visual response, black-and-white checkerboards were presented under free-viewing conditions to threegroups of 10-month-olds: siblings of children with ASD (N=47), ADHD (N=21) and controls (N=18). Continuous EEG wasrecorded and VEPs time-locked to checkerboards presentation computed.Analysis of VEPs amplitude and latency revealed statistically significant group differences in the first 200ms post-stimulusonset. Early components were enhanced in amplitude (P100) and delayed in latency (P100-N100) in at-risk infants comparedto controls (p<.05).Atypical VEPs to low-level information might index a domain-general aberration in at-risk populations. The nature of thisatypicality will be further investigated by analyzing its association with background EEG.