The Non-Linear Development Of The Right Hemispheric Specialization For Human Face Perception

Abstract

The developmental origins of human adults right hemispheric specialization for face perception remain unclear. On the one hand, infant studies have generally shown a right hemispheric advantage for face perception. On the other hand, the adult right hemispheric lateralization for face perception is thought to slowly emerge during childhood, due to reading acquisition, which increases left lateralized posterior responses to competing written material (i.e., visual letters and words). Since methodological approaches used in infant and children usually differ, resolving this issue has been difficult. Here we tested 5-year-old preschoolers varying in their level of visual letter knowledge with the same fast periodic visual stimulation (FPVS) paradigm leading to strongly right lateralized electrophysiological occipito-temporal face-selective responses in 4- to 6-month-old infants (de Heering & Rossion, 2015). Childrens face-selective response was much larger and more complex than in infants, but did not differ across hemispheres. However, there was a small positive correlation between preschoolers letter knowledge and their right hemispheric specialization for faces. These observations suggest that several factors contribute to the adult right hemispheric lateralization for faces, and point to the value of FPVS coupled with electroencephalography to assess specialized face perception processes throughout development with the same methodology.