Abstract
PURPOSE. Research has suggested that 2-month-old infants can perceive face-like stimuli as a unique configuration of features. The face configuration parameters necessary for infants to discriminate between faces, however, have not been examined. To investigate the configurational parameters that support discrimination, synthetic face stimuli (Wilson et al., 2002), both frontal and 20-degree side views, which equate faces on all parameters except geometric variability were used. Specifically, this study was designed to determine how much geometric variation between faces is necessary for infants to discriminate them. METHODS. A cueing paradigm was used in which 6- to 7-month-olds saw mean face cues that predicted the appearance of targets on one side and face cues that geometrically varied by either 3, 5, 7 or 10% predicted targets that appeared on the other side. Eye movements were analyzed for correct anticipation of the targets in response to which face cue had been presented. RESULTS. When seen in frontal view, infants exhibited above chance correct anticipations for mean vs. 5 and 10% face comparisons but not mean vs. 3%. When seen in the side view, infants exhibited above chance correct anticipations only for the mean vs. 10% variability comparison. CONCLUSIONS. Infants thus rely on the overall variability in configuration to discriminate between individual faces. Moreover, infants' discrimination is consistent with adults' (Wilson et al., 2002) in the amount of variability necessary and that less variability is needed for frontal than side views, suggesting the recruitment of the same neural mechanisms.
Supported by Natural Science and Engineering Research grant 503860 to SAA.