Age specific interactions between race and gender in infant ERP response to faces

• In Event: Poster Session 13
  In Poster Session: PS 13 Topic - Perceptual, Sensory, Motor

Abstract

From birth, infants preferentially look at faces over other visual cues. Studies exploring infant response to familiar and unfamiliar faces suggest that race and gender may modulate attention (Marquis & Sudgen, 2019). Race and gender play a significant role in social understanding in adulthood, but there is no consensus on how they interact in infants. We examined the additive and interactive effects of race and gender on Event Related Potential (ERP) responses, specifically the N290 and P400 components which are associated with face processing in infants (de Haan et al, 2003). We hypothesized that an interactive effect of race and gender would modulate these responses in 3, 6, and 9 month old infants, and that this effect would intensify with age due to the perceptual narrowing that comes with visual experience.
This data was collected as part of a cross-sequential study of infant ERP responses to faces. Infants saw static pictures of male and female faces, of either the infant’s own race, or another race selected from the SuMo database, while electroencephalography data (EEG) was recorded (Sudgen & Moulson, 2013). “Own race” was defined as the self reported race of the infants’ mother or primary caregiver. “Other race” faces did not match either of the infants’ parents. The sample consisted of 24 3-month-olds, 26 6-month-olds, and 18 9-month-olds.
Regions of interest (ROI) and time windows were selected from prior studies (Figure 1). We used linear mixed effect (LME) models to assess the effects of ROI, age, face race, and face gender, and a quadratic age term on the amplitudes of both components. Analysis of the peak N290 amplitude corrected for P1 peak (i.e., peak to trough) revealed main effects of ROI and race (ps<.05), with larger amplitudes for own race faces. Analysis of the uncorrected average N290 amplitude showed additional effects of the quadratic age term, as a main effect and in interaction with race and gender, with greater amplitude for other-race than own-race male faces (ps < 0.05).
The mean P400 amplitude was significantly affected by ROI, age, race, the interaction between gender and race (all ps<.05), and a three-way interaction between gender, race, and age (F[1,1275] = 3.97, p=.046). To explore this interaction, effects of race, gender, and ROI on the P400 were assessed at each age. In 3 month olds, P400 amplitude was increased for other race faces (p=.024). In 9 month olds, a significant interaction between race and gender (F[1,323] = 18.39, p<.001) was driven by increased P400 amplitudes to female own-race, and male other-race faces (Figure 2).
The effects seen on the P400 and N290 add a neural dimension to previous studies of infant attention to faces. Our next step will be applying cortical source analysis to additionally investigate what areas of the brain are active during face processing, and whether our results reflect age-based changes in cortical activation during face processing as a function of race and gender.

Authors

• Kira Ashton, American University
  Presenting Author

• Fabiola Fernandez, American University
  Non-Presenting Author

• Nicole Sugden
  Non-Presenting Author

• Margaret C Moulson, Toronto Metropolitan University
  Non-Presenting Author

• Laurie Bayet, American University
  Non-Presenting Author