Infant selective attention and perceptual learning of multimodal face stimuli

• In Event: 2-104 - Infant Attention and Face Learning: Insights from Measures of Brain and Behavior

Integrative Statement

Previous research has shown that initial learning conditions affect infant face processing. For example, infants show evidence of enhanced attention and more efficient perceptual processing when provided with synchronous audiovisual presentations of faces during initial learning in comparison to asynchronous audiovisual presentations or unimodal visual presentations of faces during initial learning (Reynolds, Bahrick, Lickliter, & Guy, 2014). This intersensory facilitation is likely due to the intersensory redundancy provided by the synchronous and redundant presentation of perceptual information to multiple sense modalities. Bahrick and Lickliter (2012) proposed that intersensory redundancy selectively recruits infant attention to and processing of amodal information that is perceived redundantly across multiple senses. This enhanced selective attention to amodal stimulus properties occurs at the expense of selective attention to modality-specific stimulus properties that can only be perceived through a single sense. The current study utilized event-related potentials (ERP) to test the hypothesis that intersensory redundancy leads to prioritization of selective attention and perceptual processing of amodal information over modality-specific information provided by multimodal face stimuli. Our analyses focused on the P400 ERP component associated with infant face processing and the late slow wave (LSW) ERP component associated with infant recognition memory. We predicted that infants would demonstrate differential amplitude of the P400 and LSW components based on changes in affect (an amodal stimulus property) between familiar and novel face stimuli. In contrast, we predicted no differences would be found in P400 and LSW amplitude based on changes in facial features (a modality-specific stimulus property) between novel and familiar face stimuli.

Five-month-old infants (N=14) were tested in an ERP procedure with a training phase and testing phase. In the training phase, infants were exposed to 20 repetitions of a video clip of a woman reciting a phrase conveying either positive or negative affect. In the testing phase, infants were shown three different stimulus types (familiar, novel-affect, novel-face). On familiar trials, infants were shown the familiar actress conveying the same affect shown during training. On novel-affect trials, infants were shown the familiar actress conveying the opposite affect of that shown during training. On novel-face trials, infants were shown a novel actress conveying the same affect that was conveyed during training. The P400 component was analyzed as the mean amplitude of the ERP at posterior electrodes from 375 - 500 following stimulus onset, and the late slow wave (LSW) was analyzed as the mean amplitude of the ERP at temporal electrodes from 750 - 1500 ms following stimulus onset.

Infants demonstrated significantly greater P400 amplitude on novel-affect trials in comparison to familiar trials, and no differences in P400 amplitude on novel-face trials in comparison to novel-affect trials. Similarly, infants demonstrated significant differences in the amplitude of the LSW on novel-affect trials in comparison to familiar trials, and no differences were found for novel-face trials in comparison to familiar trials (see Figure 1). These findings provide support for the hypothesis that intersensory redundancy directs infant attention to amodal properties of face stimuli while diverting their attention from modality-specific facial characteristics.

Authors

• Greg D. Reynolds, University of Tennessee
  Presenting Author

• Lorraine E Bahrick, Florida International University
  Non-Presenting Author

• Robert Lickliter, Florida International University
  Non-Presenting Author

• James Torrence Todd, Florida International University
  Non-Presenting Author

• Kelly Roth, University of Tennessee Knoxville
  Non-Presenting Author

• William Joseph Chollman, University of Tennessee
  Non-Presenting Author