Poster #4 - Cortical Sources of Own- and Other-Species Face Processing

• In Event: Poster Session 20

Abstract

Perceptual narrowing is a developmental phenomenon characterized by a narrowing of perceptual sensitivity from a broad range of stimuli in early development to a narrower range of stimuli commonly encountered in the native environment in later development (Maurer & Werker, 2014). Six-month-old infants are able to discriminate between novel and familiar monkey faces at the individual level. By 9 months of age, infants no longer demonstrate this ability for monkey faces but retain the ability to discriminate between individual human faces (Pascalis et al., 2002). Studies utilizing event-related potentials (ERP) have identified the P1 and N290 components as ERP components associated with face processing in infancy. The P1 is associated with low-level visual processing and categorization of faces and objects (Pekarjou et al., 2014), and the N290 is associated with more specialized face processing (de Haan, 2007). Work utilizing cortical source analysis on infant ERP data in response to human faces indicates that the P1 is generated in the lingual and parahippocampal gyri and the N290 is generated in the fusiform gyrus (Conte, Richards, Guy, Xie, & Roberts, 2020). However, no study to date has examined cortical sources involved in other-species face processing in infancy. In the current study, we utilize cortical source analysis to identify the neural generator(s) of the P1 and N290 components for infants of 10 to 12 months of age during initial exposure to either human (N = 9) or monkey faces (N = 8). High-density EEG (124 channels) was measured while infants were shown 20 repeated 1000ms presentations of a single face. For the source analysis of the ERP data, realistic head models are generated for each participant based on their head measurements. Structural MRIs from the Neurodevelopmental MRI Database are used from infants close in head size to each participant (Richards et al., 2015). A finite element method head model is then generated with source dipoles restricted to gray matter in Regions of Interest (ROI). Current density amplitude in source locations is estimated with the CDR technique and exact-LORETA (Pascual-Marqui et al., 2011). The ERP data are used to estimate the CDR amplitudes for each ROI. Preliminary results were analyzed using repeated-measures ANOVA with a between-subjects factor of species (human, monkey) and a within-subjects factor of ROI (anterior fusiform gyrus, posterior fusiform gyrus, lingual gyrus, parahippocampal gyrus). There was a main effect of ROI for the analysis of the P1 component (F(3,45) 3.21, p = .03, ηp2 = .176). CDR amplitude was greatest at the parahippocampal gyrus regardless of species. Analysis of the N290 revealed an interaction of species and ROI that approached significance (F(3,45) 2.52, p = .07, ηp2 = .144). Infants showed greater CDR amplitude in anterior fusiform gyrus in response to human faces. These preliminary findings may indicate overlap in brain regions recruited during the early stages of visual processing (P1) of human and monkey faces. Greater recruitment of fusiform gyrus for the N290 may reflect increasing specialization for processing human faces for infants by 10 – 12 months of age.

Authors

• Kenna R. H. Clayton, University of Tennessee - Knoxville
  Presenting Author

• Stefania Conte, University of South Carolina

• Lauren Slivka, University of Tennessee - Knoxville

• Kelly Roth

• John E Richards, University of South Carolina

• Greg D. Reynolds, University of Tennessee - Knoxville