Perceptual and memorial impairment in developmental prosopagnosia.

Despite the high suspected prevalence of developmental prosopagnosia, diagnostic criteria are informal, current treatment approaches lack trials validation, and, given the relatively small number of group studies, the relative integrity of underlying perceptual and memory processes remains unclear. To begin to address these shortcomings, we administered a large battery of behavioural tests to twenty one individuals with self-reported face recognition difficulties. Ten of these individuals were subsequently classified as developmentally prosopagnosic based on the most widely used assessments - the Cambridge Face Memory Test and famous faces naming test. Relative to a control sample (n=103), the majority of these individuals performed poorly on tests of memory but not perception. These results help clarify the nature of impairment in developmental prosopagnosia, and also guide the development of novel therapies such as caloric vestibular stimulation, a technique that we have begun to apply to this population and which, as will be described, may hold promise.