Early visual deprivation affects the development of face recognition and of audio-visual speech perception

Abstract

The investigation of patients treated for bilateral congenital cataracts allows to study the development of visual and multisensory functions after a period of visual deprivation in early infancy. In the present study, cataract patients were tested for their capability to recognize faces and to integrate auditory and visual speech information. In Experiment 1, 12 cataract patients were tested with the Benton Facial Recognition Test. In Experiment 2, a McGurk paradigm was used that investigated audio-visual interaction and lip-reading capabilities. Here, fifteen cataract patients participated and were compared to normally sighted controls and to visually impaired controls. In the Benton Facial Recognition Test, cataract patients' performance was unimpaired when target and test face were identical. By contrast, they performed worse than a normally sighted control group when head orientation and/or lighting conditions of the test faces were changed. In the McGurk paradigm, cataract patients displayed impaired lip-reading abilities and a reduced audio-visual interaction compared to normally sighted controls. The latter deficit prevailed even in a sub-group matched for lip-reading capacities with a normally sighted control sub-group. These results suggest that visual input in early infancy is a prerequisite for a normal development of visual and multisensory functions.