Poster #188 - Differential Neural Processing of Identity and Emotion in Infancy is Associated With Later Social Development

• In Event: 3-159 - Poster Session 12
  In Poster Session: PS 12 Section - Social Cognition

Integrative Statement

Looking time studies have found that young infants show differential attention to faces based on familiarity (e.g., Field et al., 1984) and emotional expression (e.g., Barrera & Maurer, 1981). Based on work by Minagawa-Kawai et al. (2009), the current study used functional near-infrared spectroscopy (NIRS) to measure neural processing of familiar and unfamiliar faces expressing neutral and positive emotions in 6- to 12-month-olds. Additionally, relations between individual differences in neural responses and social behaviors were examined.

A 24-channel Hitachi ETG-4000 NIRS system recorded changes in oxyhemoglobin (OxyHb) while infants viewed 32s videos of their mother or a stranger talking (sound removed) while displaying a neutral expression for 16s then a happy expression for 16s. Analyses focused on two regions of interest (ROIs) based on past infant work: Frontal and Right Posterior. Mean OxyHb responses to Mother Neutral, Mother Happy, Stranger Neutral, and Stranger Happy were calculated for the window between 6 and 16s after stimulus onset. Forty-eight infants (13 6-month-olds, 17 9-month-olds, 18 12-month-olds) contributed three or more artifact-free trials in one or both ROIs for each of the four conditions and were included in the present analyses.

Repeated-measures ANOVAs included Identity (Mother, Stranger) and Emotion (Neutral, Happy) as the within-subjects factors, and Age (6mo, 9mo, 12mo) as the between-subjects factor. The Frontal ROI revealed no significant effects. The Right Posterior ROI showed an Identity x Emotion interaction (p = .048), though post-hoc t-tests did not reveal significant OxyHb differences between any of the four conditions (ps > .17). A main effect of Age was also found (p = .004), whereby OxyHb responding was similar at 6 and 9 months, but significantly lower at 12 months.

Scores were calculated for Mother face bias (average OxyHb for Mother conditions minus average OxyHb for Stranger conditions) and Happy face bias (average OxyHb for Happy conditions minus average OxyHb for Neutral conditions) in the Right Posterior ROI. Correlations were run between these bias scores and social development at 12 and 18 months, as measured using the Communication and Symbolic Behavior Scales (CSBS; Wetherby et al., 2002). At 6 months, increased Mother face bias in OxyHb was associated with lower 18-month social scores (p = .004; see Figure 1). At both 9 and 12 months, increased Happy face bias in OxyHb was related to higher social scores at 12 months (p = .012, p = .040, respectively; see Figure 2), and this association was marginal for 6-month-olds (p = .063).

In summary, the current study found a) decreased OxyHb responding to faces in Right Posterior regions between 9 and 12 months, b) greater bias in OxyHb responses to Mother at 6 months negatively predicted social behavior at 18 months, and c) greater bias in OxyHb responses to Happy faces at 9 and 12 months were positively associated with social behavior at 12 months. These correlations suggest mechanisms by which increased neural processing of unfamiliar faces at 6 months and positive emotions at 9 and 12 months could reflect adaptive processing of social information.

Authors

• Jennifer Wagner, City University of New York, College of Staten Island
  Presenting Author

• Katherine Perdue, Harvard Medical School
  Non-Presenting Author

• Helen Tager-Flusberg, Boston University
  Non-Presenting Author

• Charles A. Nelson, Harvard Medical School
  Non-Presenting Author