How Does All this Functional Organization Arise over Development?

titleHow Does All this Functional Organization Arise over Development?
start_date2023/12/12
schedule10h
onlineno
location_infoSalle Jaurès
summaryAs described in the first two lectures, the last 25 years of research in human cognitive neuroscience have given us a glorious new picture of the functional organization of the human cortex, with dozens of regions, each specialized for a particular mental function, all present in approximately the same location in every normal person. It is impossible not to wonder how the precursors of all of this intricate and systematic structure arose over evolution, and how the structure of the cortex gets built in the life of each individual. Although these are among the hardest questions to answer about the human brain, tantalizing clues are beginning to emerge. Here I review recent findings from my collaborations with Rebecca Saxe and Heather Kosakowski, who developed methods for functionally scanning awake human infants. We have found that the FFA, PPA, and EBA are all present, in adultlike locations, and with approximately adultlike selectivity, by 6 months of age, and music selective responses appear to be present in the auditory cortex of sleeping one-month-old infants. The early appearance of these selective responses limit the total amount of experience available to instruct the development of these regions. But how do these regions "know" where to arise in the cortex ? Multiple lines of evidence suggest that early-developing long-range connections from one cortical region to another play a central role in determining the cortical location where each selectivity arises. Indeed, the location of visual word form area, which responds selectively to words and letterstrings only after children are taught to read, can be predicted from patterns of cortical connectivity in the same children before they learn to read. Currently contested theories appeal to bottom-up developmental processes that construct perceptual processing systems from the sensoria inward, versus top-down processes that invoke not just the perceptual properties of the stimulus, but its significance to the infant.
responsiblesde Vignemont