Wds) Key A., Stone W.,

¶ … Wds)

Key A., Stone W., and Williams S. "What Do Infants See in Faces? ERP Evidence of Different Roles of Eyes and Mouth for Face Perception in 9-Month-old Infants." Infant and Child Development; Vol 18 (2009): 149-162.

Experimental Background and Context

Within the field of infant development and human cognitive psychology, it is well-known that infants begin to recognize human faces very early. In general, this is believed to have obvious evolutionary advantages. Volumes of prior literature have documented research into different aspects of facial recognition in infants, ranging from those involving newborns to related studies of toddlers.

While much attention has been devoted to understanding the general aspects of facial recognition in infants, comparatively little empirical literature is available on the specific roles of different elements of facial recognition, such as the comparative significance of isolated facial features. This study was designed to compare the respective importance of the eyes and the mouth and to identify any specific conclusions capable of being drawn with respect to comparative differences in the way that 9-month-old infants process information about the eyes and the mouths of two dimensional visual depictions of adult faces.

For example, previous studies of newborns found that newborn infants exhibit greater interest in human faces than in inanimate objects. Four-day-old infants recognize differences in the overall shape of different faces but that recognition is based on external features; they are unable to distinguish faces based only on facial features. At five weeks of age, infants can recognize their mothers by facial features alone; and 7-8-month-old infants can recognize differences in internal facial geometry.

Study Design and Methodology

This study used a high-density array net of electrodes embedded in soft sponges placed at specific points known to correspond to regions of neural activity associated with visual recognition. By recording changes in brain activity in those regions as represented by changes in event-related potential (ERP), the researchers hoped to identify patterns of visual recognition that corresponded specifically to the ability of the subjects to perceive changes in the appearance of mouth shape and position as opposed to changes in eye shape and position on the visual depictions of adult faces. In thirty-percent of the trials, the mouths or eyes of the models (smiling adult females) in the photographs were replaced with the mouths or eyes of different adult females.

Findings and Conclusions