HEMISPHERIC ASYMMETRY IN EARLY LIFE: TACTILE PROCESSING

The present series of studies are designed to explore the early development
of right hemispheric specialization for tactual processing, an area of
research which, in infants and young children, has received scant
attention. These studies build upon our earlier work in which, using a
newly developed measure of cross-modal transfer we found a right
hemispheric superiority for tactual procesing of form in children as young
as two years of age. Since cerebral lateralization is a particularly
salient aspect of information processing among adults, understanding how
and when young children develop similar asymmetries may contribute to our
understanding of early brain function. Six studies of tactual processing are designed to assess (1) the
replicability of our initial findings in right-handed children aged 1-5
years, the likelihood that the left hand advantage found initially reflects
a right hemisphere advantage for processing forms globally, as spatially
organized wholes, and the extent to which tactual processing is similarly
lateralized in left handers, (2) the role of differential tactile
thresholds and finger dexterity in the left hand advantage, (3) the degree
to which hemispheric asymmetries increase from 1- to 2- years, a period
singled out for intensive study in view of our initial failure to find any
indication of hemispheric specialization in infants as young as one year of
age, (4) the specificity of the interference found in our initial studies
when music was introduced during palpation, (5) the developmental course of
lateralization for speech and music processing (medoly recognition), and
(6) the extent to which the presence of asymmetries may be underestimated
in the cross-modal paradigm. The long range goal of this research is to understand better (a) the degree
of lateralization present early in life for tactual processing (b)
developmental changes or continuities in functional cerebral organization
and (c) the implications of early asymmetries for perceptual and cognitive
functioning.