Abstract
Preference of infants for human faces is presumably of great importance for later development of social cognition. Human faces contain various types of information, of which emotional facial expression and gaze direction are particularly important. In the present research, we determined whether gaze directions influence discrimination of emotional facial expressions in infants. In order to assess their ability, we measured the latency to disengage their attention from face stimuli presented at the center of their visual field. The face was posing either happy or angry facial expression, and the gaze was directed either straight to or averted from the viewers. At the start of each experimental trial, a human face was presented. When the infants fixated on the face, the geometrical target was presented at the periphery of their visual field. We measured the latency of infants to make a saccadic eye movement to peripheral target, and compared the SRTs (saccadic reaction time) across Gaze Direction (2) x Facial Expression(2) = 4 experimental conditions. The longer the SRT was, the more effectively the face stimuli captured attention of infants. The analysis revealed that SRT was significantly longer for angry faces than for happy faces when the gaze of the stimulus face was looking straight, while no such tendency was found when the gaze of the stimulus face was averted. The indications of this finding are discussed in the context of the development of visual attention and social cognition during infancy. [J Physiol Sci. 2007;57 Suppl:S109]
