High-Density EEG and ERP Laboratory Abstract

Richards, J.E., Guy, M.W., & Zieber, N. (2015). Cortical sources of the face-sensitive N290 component in infants. Paper presented at the Flux Conference, Leiden, Netherlands, September 2015.

Specialized processing of faces begins early in life, yet we are just beginning to understand the neural underpinnings of the development of face expertise in infancy. In infants, the N290, is a negative deflection over posterior regions peaking at 290ms that is greater in amplitude for faces than visual noise (Halit, Csibra, Volein, & Johnson, 2004). In the current study, infants’ ERPs were recorded while infants of three different ages (4.5, 6, and 7.5 months) passively viewed faces and objects (toys). Cortical source analysis with realistic head models was used to identify the location of the cortical sources of this component. Infants viewed a series of brief stimulus presentations (500 ms) of images of their own mother, another infant’s mother, their own toy, or another infant’s toy randomly interspersed across trials. High-density EEGs were recorded using an EGI 128-channel Geodesic Sensor Net. The N290 component increased in amplitude from 4.5 to 7.5 months, and was different to faces and toys. Current Density Reconstruction (CDR) with realistic head models and anatomically-defied ROIs were used to examine the sources of the component. There was a peak in the CDR at in the middle fusiform gyrus at the time of the N290; this peak was greater for faces than toys, and increased across age. There was a generalized response across several other lateral brain areas that did not show this N290 latency peak, and these appear to be precursors of ERP components occurring later in processing (i.e.g, P400, Nc)