Configural and featural processing in humans with congenital prosopagnosia

Abstract

Prosopagnosia describes the failure to recognize faces, a deficiency that can be devastating in social interactions. Cases of acquired prosopagnosia have often been described over the last century. In recent years, more and more cases of congenital prosopagnosia (CP) have been reported. In the present study we tried to determine possible cognitive characteristics of this impairment. We used scrambled and blurred images of faces, houses, and sugar bowls to separate featural processing strategies from configural processing strategies. This served to investigate whether congenital prosopagnosia results from process-specific deficiencies, or whether it is a face-specific impairment. Using a delayed matching paradigm, 6 individuals with CP and 6 matched healthy controls indicated whether an intact test stimulus was the same identity as a previously presented scrambled or blurred cue stimulus. Analyses of d values indicated that congenital prosopagnosia is a face-specific deficit, but that this shortcoming is particularly pronounced for processing configural facial information.

Keywords: face perception; object perception; prosopagnosia; visual cognition.

Figure 1.

Examples of stimuli used: Intact, blurred, and scrambled versions of face (A), house (B), sugar bowl stimuli (C). Intact and scrambled stimuli were presented in colour.

Figure 2.

Mean d' values for scrambled and blurred trials, separated by group and stimulus type. Error bars depict standard errors of the mean (SEM). blr = blurred, scr = scrambled.