Abstract
The developmental origin of the human right hemispheric lateralization for face perception remains unclear. According to a recent hypothesis, the increase in left lateralized posterior neural activity during reading acquisition contributes to, or even determines, the right hemispheric lateralization for face perception (Behrmann & Plaut, 2013). This view contrasts with the right hemispheric advantage observed in few months old infant. Recently, a Fast Visual Periodic Stimulation (FPVS) paradigm in EEG showed that periodically presented faces among objects lead to strongly right lateralized face-selective responses in 4-6 months old infants (de Heering & Rossion, 2015). Here we used the exact same paradigm in EEG to study the lateralization of responses to faces in a group (N=35) of 5 years-old pre-school children showing left-lateralized responses to letters (Lochy et al., 2016). Rather surprisingly, we found bilateral face-selective responses in this population, with a small positive correlation found between preschool letter knowledge and right hemispheric lateralization for faces (rho=0.30; p< 0.04), but no correlation between the left lateralization to letters and the right lateralization to faces. However, discrimination of facial identity with FPVS (Liu-Shuang et al., 2014) in these pre-reading children was strongly right lateralized, and unrelated to their letter knowledge. These findings suggest that other factors than reading acquisition, such as the posterior corpus callosum maturation during early childhood as well as the level required by the perceptual categorization process (i.e., generic face categorization vs. face individualization), play a key role in the right hemispheric lateralization for face perception in humans. References Berhmann, M. & Plaut, DC. (2013). TICS, 17(5), 210-219. De Heering, A. & Rossion, B. (2015). E-life 2015;4;e06564. Liu-Shuang, J. et al. (2014). Neuropsychologia, 52, 57-72. Lochy, A. et al. (2016). PNAS, 113: 8544-8549.
Meeting abstract presented at VSS 2017