Experiential influences on the development of face perception

Abstract

<p>This thesis examined the role of experience in the development of face perception. In Experiments 1-4, I examined the role of experience in the development of the perception of attractiveness by testing whether facial features that influence adults' ratings similarly influence babies too young to have been affected by cultural conditioning. In Experiment 1, adults rated faces with larger eyes as more attractive than faces with smaller eyes, and 5-month-olds looked longer at faces with larger eyes. In Experiments 2-4, adults rated faces with features at a medium or low height (large forehead, small chin) as more attractive than faces with high features (small forehead, large chin), whereas 5-month-olds looked equally long at those faces. In Experiment 5, there was no effect of the features' height in 3-year-olds, except those with more exposure to peers, who rated low features as more pretty than high features. The results suggest that the adult preference for larger eyes begins during infancy but that preferences for features at an average or low height emerge later, only after additional experience with faces and/or cultural learning. To see whether early visual experience is critical for the development of adult skills in face processing, in Experiments 6 and 7 I compared normal adults and children to patients deprived of visual input during early infancy because of bilateral congenital cataracts. Patients performed abnormally in tasks requiring matching facial identity, holistic processing, and the differentiation of faces based on local and configural processing. Patients performed normally in tasks requiring the processing of large, local features under longer exposures: lip reading, matching facial expression and gaze direction. They were also normal on a task requiring efficient configural processing of shapes. Results from the normal groups indicate that skills in face processing are not fully developed by age 6, but are adultlike at 10 years. Combined, the results suggest that early exposure to faces sets up the cortical circuits that become specialized for face processing, and that those circuits are shaped by years of experience differentiating among faces.</p>