An in-depth investigation of face perception in developmental prosopagnosia

Developmental prosopagnosia (DP) causes difficulty recognizing familiar faces, but little is known about which stage(s) of the face-processing system difficulties occur, or whether these are identical in all DP cases. Twenty DPs and matched controls completed six face perception tasks. The DP group performed significantly poorer than controls on face detection and gender categorization tasks and on a global (averaged) face perception measure. 40% of individual DPs showed significant impairments on tasks not involving identity perception (face detection and categorization, age and gender categorization). By contrast, 50% showed broadly typical face perception and thus support for the idea of apperceptive (affecting both face perception and face memory) and mnemonic (affecting only face memory) subtypes of DP. Intraclass correlations revealed clear inter- and intra-individual differences, confirming that data from a single perceptual task cannot be taken as evidence of broader face-perception ability spanning beyond the results of that test..