The development of face perception in infancy: Intersensory interference and unimodal visual facilitation.

Abstract

Although research has demonstrated impressive face perception skills of young infants, little attention has focused on conditions that enhance versus impair infant face perception. The present studies tested the prediction, generated from the Intersensory Redundancy Hypothesis (IRH), that face discrimination, which relies on detection of visual featural information, would be impaired in the context of intersensory redundancy provided by audiovisual speech, and enhanced in the absence of intersensory redundancy (unimodal visual and asynchronous audiovisual speech) in early development. Later in development, following improvements in attention, faces should be discriminated in both redundant audiovisual and nonredundant stimulation. Results supported these predictions. Two-month-old infants discriminated a novel face in unimodal visual and asynchronous audiovisual speech but not in synchronous audiovisual speech. By 3 months, face discrimination was evident even during synchronous audiovisual speech. These findings indicate that infant face perception is enhanced and emerges developmentally earlier following unimodal visual than synchronous audiovisual exposure and that intersensory redundancy generated by naturalistic audiovisual speech can interfere with face processing.

Temporal Dependency and the Structure of Early Looking

“…These 127 infants were part of a larger study in which mean performance for a variety of variables was reported, including total time to habituation, the look-away rate during habituation, the mean duration of the first two habituation trials, mean looking time over test trials, and visual recovery scores [2,31]. The durations of infants’ individual looks and the durations of total looking times within individual trials—the focus of the current study—have not been published.…”

“…Dynamic color video displays of infant-directed speech served as the stimulus events [2,32–34]. Three actress’ faces and shoulders were videotaped as they recited “Mary Had a Little Lamb” (18 s) and “Jack and Jill” (12 s).…”

“…During these test trials, 35 infants were presented with a novel face speaking with a familiar voice to assess face discrimination [2]; 15 infants were presented with a familiar face speaking with a novel voice to assess voice discrimination [33]; and 33 infants were presented with a novel face-voice combination to assess face-voice discrimination [34]. Visual recovery was calculated by subtracting the mean duration of the final two habituation trials from the mean duration of the two test trials.…”

“…Next we explored whether temporal dependency was present not only between individual looks but between trials of looking (aggregating over individual looks), a standard unit of analysis in studies using habituation procedures [2,15,22,23]. A specific goal was to assess whether the last trial of looking to the habituation stimulus predicted looking to the novel test stimulus.…”

Young children are natural pedagogues

“…Each eye contact the child made was coded when it occurred and in relation to which experimenter, adult pupil or teacher; (2) Contingent Reactivity, the degree of engagement, was evaluated as a repertoire of voluntary movements and facial expressions and then measured as high, intermediate and low (Csibra, 2010). Faces of people are highly salient to young infants and convey information for social interactions (Bahrick, Lickliter, & Castellanos, 2013);…”