Abstract
Introduction: Amblyopia is the commonest cause of childhood visual impairment and has been understood as a low-level vision problem. We ask whether amblyopia has consequences for face recognition, comparing left-eye (LE) to right-eye (RE) amblyopes. The slower development of the nasal vs. the temporal hemifield pathway in infancy (Lewis and Maurer, 1992) predicts that LE deprivation should disproportionately hinder input to the developing face-processing-implicated right brain hemisphere, potentially causing a larger face processing deficit in LE than RE amblyopia. Methods: We recruited and tested 3936 participants, unselected with regard to amblyopia or face recognition ability, via our website Testmybrain.org. Participants reported whether they have or had amblyopia, and, if so, in which eye. As a measure of face recognition ability, they also took the Cambridge Face Memory Test (CFMT; Duchaine and Nakayama, 2006). Results: In all, 252 participants indicated that they have or had amblyopia. Of these, 193 indicated which eye was affected (LE=119, RE=74). LE amblyopes recognized faces more poorly than both RE amblyopes (p=0.005) and non-amblyopic controls (p=0.014). RE amblyopes recognized faces slightly, but non-significantly, better than controls (p=0.14). Conclusion: We find a face recognition deficit in LE, but not RE, amblyopia, indicating that amblyopia can impact high-level vision. The specificity of this deficit to LE amblyopia rules out current visual acuity as an explanation, since LE and RE amblyopes have similar acuity. Our work also extends the prior finding of a face perception deficit specific to LE (not RE) congenital cataract patients (LeGrand et al, 2003) to a condition, amblyopia, with less extreme visual deprivation and to a test, CFMT, that has been tied to everyday social functioning.
Meeting abstract presented at VSS 2012