Abstract
Infants show an interest in faces from birth (Johnson & Morton, 1991). In both children and adults, face recognition is more dependent on the right hemisphere (RH) than the left hemisphere (LH) of the brain. Does the RH also drive infants' early interest in faces? To answer this question, 3-month-old infants (n=53) were recruited to view moving schematic faces paired with scrambled faces on a screen. Infants were randomly assigned to a viewing condition: binocular (BIN), left eye open (LEO), or right eye open (REO). Research suggests that the nasal retina develops before the temporal retina (Lewis & Maurer, 1990). Thus, early in infancy (i.e. prior to 6-months) visual information should travel predominantly from one eye to the contralateral hemisphere (LeGrand et al., 2003). Other work suggests little-to-no visual information transfer between hemispheres prior to 2-years-of-age (Liegeois et al., 1997, 2000). Following this logic, the BIN infants in our study would be expected to process the stimuli with both hemispheres, while LEO infants should process the stimuli primarily with the RH, and REO infants with the LH. We recorded the infants' eye movements using a screen-mounted camera and coded looking behavior. Overall, BIN infants spent more time looking at faces than scrambled faces (p=0.03). There was no difference in looking behavior for LEO or REO groups (ps>0.10). However, in the second block of trials, BIN infants and LEO infants spent more time looking at faces than scrambled faces (ps< 0.009), but REO infants had no preference (p=0.939). Thus, in later trials, infants processing the stimuli with the RH demonstrated a preference for looking at faces, while infants using the LH only did not. This effect did not extend to non-face objects (flowers). These findings suggest that infants' early interest in faces is mediated by the right hemisphere of the brain.
Meeting abstract presented at VSS 2018