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.

Figure 1

Static images of the two dynamic face events used in Experiments 1 and 2. Infants were habituated to one face and tested with the other face (order counterbalanced across infants) in sequential habituation and test trials.

Figure 2

Two-month-old infants (N = 48): Mean visual recovery (and SD) to a novel face as a function of stimulus condition (synchronous audiovisual, unimodal visual, asynchronous audiovisual).

Figure 3

Three-month-old infants (N = 32): Mean visual recovery (and SD) to a novel face as a function of stimulus condition (synchronous audiovisual, unimodal visual).