Brown Bag du 06/07/17 à 11h00 Parvaneh Adibpour



"Anatomo-functional correlates of visual and auditory development
during early infancy "

Several cognitive functions, such as language processing, handedness, and
face recognition, are lateralized in the adult human brain. The ontogeny
of these functional asymmetries is still poorly understood. We study the
development of visual and auditory networks, with a focus on the ontogeny
of lateralization for face and language processing within each network in
early infancy.
In a first study, using structural MRI and a face discrimination EEG
paradigm with lateralized presentation of faces, we investigated visual
development in infants between 1-6 months of postnatal life. We assessed
the maturation of early visual responses and their inter-hemispheric
transmission with respect to the structural maturation of the underlying
white matter pathways conducting these responses. We show that the corpus
callosum is sufficiently mature to transfer visual information from one
hemisphere to the other. Looking at face-specific responses, we reveal
that only the right hemisphere shows evidence for face discrimination when
presented in the left visual hemifield. This capability improves
throughout the first semester of life in the right hemisphere with no
evidence of discrimination in the left hemisphere, highlighting the
differential left-right organization of visual cortices in the human brain
established already in infanthood. In a second study, we investigated the
development of auditory network in healthy infants and infants with
agenesis of corpus callosum. Using EEG, we examined how the absence of
corpus callosum would impact auditory processing. We report two main
findings:1. Different spatial distribution of auditory responses in the
two groups 2. Asymmetrical interhemispheric transfer of auditory
information, through the corpus callosum, potentially interacting with the
emergence of language function in the left hemisphere.