Neuropsychological mechanisms of false facial recognition following frontal lobe damage

Previous neuropsychological studies have demonstrated an association betwee n false recognition and frontal lobe dysfunction. In the experiments report ed here we explore the contribution of memory impairment and executive dysf unction to the pathogenesis of false facial recognition in patients with fo cal frontal lobe damage. Memory illusions in response to novel faces were o bserved in both anterograde and retrograde tests efface recognition memory. However, in neither memory domain could false recognition be accounted for by face memory loss. Instead, our findings suggest that false facial recog nition in frontal patients reflects the breakdown of strategic memory retri eval, monitoring, and decision functions critical for attributing the exper ience of familiarity to a specific source. Frontal executive memory functio ns are primarily recruited under conditions of uncertainty when the face cu e does not automatically elicit relevant contextual information, leaving th e source of familiarity unspecified. Our results indicate that frontal pati ents do not spontaneously engage in effortful recollection of specific cont exts 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 m aterial-specific.