Experience Modulates Visuocortical Responses to Faces in 3- to 6-Year-Old Children

Face processing is essential for social cognition, yet little is known about how race and gender biases in face processing develop as children encounter increasingly diverse social environments. This study investigated how preschool-aged children's prior familiarity with race and gender groups influences neural responses during face processing. Children aged 3-6 years viewed a stream of face stimuli using a fast period visual stimulation (FPVS) technique to record steady state visual evoked potentials (ssVEPs). In this task, images of different faces from one race/gender group were presented at 6 Hz (base category), with every fifth face presentation from a different race or gender, eliciting an oddball response at 1.2 Hz. Familiarity with different race and gender groups was determined by parental report. Robust frequency-tagged neural responses were observed across conditions, indicating reliable face processing responses. Faces from familiar race groups elicited larger general visual responses (6 Hz), whereas oddball responses (1.2 Hz) were enhanced for faces from unfamiliar race groups. These results suggest that children's prior familiarity with race groups biases visuocortical responses to faces and sensitivity to changes within the visual stream. No significant effects of face gender were observed. Topographic analyses revealed increasing right occipitotemporal activity with age, suggesting emerging lateralization of face processing networks. These findings demonstrate that experience with race groups, but not gender, modulates neural responses to faces in early childhood, and highlights the importance of real-world social exposure as a contributor to face-processing biases.