NEUROPSYCHOLOGICAL MECHANISMS OF FALSE FACIAL RECOGNITION FOLLOWING FRONTAL LOBE DAMAGE

Abstract

Previous neuropsychological studies have demonstrated an association between false recognition and frontal lobe dysfunction. In the experiments reported here we explore the contribution of memory impairment and executive dysfunction to the pathogenesis of false facial recognition in patients with focal frontal lobe damage. Memory illusions in response to novel faces were observed in both anterograde and retrograde tests of face recognition memory. However, in neither memory domain could false recognition be accounted for by face memory loss. Instead, our findings suggest that false facial recognition in frontal patients reflects the breakdown of strategic memory retrieval, monitoring, and decision functions critical for attributing the experience of familiarity to a specific source. Frontal executive memory functions are primarily recruited under conditions of uncertainty when the face cue does not automatically elicit relevant contextual information, leaving the source of familiarity unspecified. Our results indicate that frontal patients do not spontaneously engage in effortful recollection of specific contexts that can normally be used to oppose and inhibit recognition decisions based on general or context-free familiarity. However, frontal patients can use context recollection to suppress false recognition once this strategy is pointed out to them. In some frontal patients false recognition may be material-specific.