Sensitivity to face animacy and inversion in childhood: Evidence from event-related potentials and time-resolved classification of EEG data

Abstract

Recent evidence suggests that adults process inanimate or artificial faces as “out-groups”, with implications for the use of such faces in person perception research as well as in the design of artificial social agents. However, the developmental trajectory of the perception of inanimate faces is unknown. In the present study, we investigated the electrophysiological correlates of processing inanimate (doll) faces in children, as a function of age and face inversion. Two groups of children, 5-7 year-olds (N=18) and 8-10 year-olds (N=18), passively watched pictures of real or doll faces presented in an upright or inverted orientation. Analysis of the elicited event-related potentials, focusing on the P100 and N170 components, revealed that the amplitude of the N170 component was sensitive to face animacy in 5-10 year-old children. More specifically, the amplitude of the N170 was larger (more negative) in response to doll faces irrespective of the children’s age or of the face’s orientation. Thus, the sensitivity of the N170 to face animacy in children did not seem to necessitate or affect face-specific processing strategies. Multivariate pattern analyses of the EEG signal were additionally conducted to assess whether, and at which time post stimulus-onset, face animacy information was represented during processing. While information on face orientation could be extracted from approximately 250-350 ms post-onset in children, there was no indication that information on face animacy was reliably represented during processing at any age, including in an adult sample. Together, these results suggest that 5-10 year-old children exhibit some sensitivity to face animacy