NEUROPSYCHOLOGICAL AND NEUROANATOMICAL CORRELATES OF CONFABULATION

In the present exploratory investigation we report nine confabulatory patients of comparable age, education, and general level of intelligen ce in the acute epoch of recovery after rupture and clipping of ACoA a neurysms. Five of the nine cases had ''spontaneous'' confabulation, se vere anterograde amnesia, markedly poor attentional and executive func tions, and denial of illness. These patients all had multiple lesions that involved basal forebrain, ventral frontal lobe, and striatum. The other four patients manifested only ''momentary'' or ''provoked'' con fabulations. These patients also had severe anterograde amnesia but sh owed relatively mild deficits in executive functions. These patients h ad lesions restricted to the basal forebrain except for one who had ad ditional orbital frontal damage. Analysis of these two groups of confa bulatory patients suggests that there is a common profile of deficits and anatomic foundation associated with confabulation; ''spontaneous'' confabulation appears to require extensive, simultaneous disruption o f medial basal forebrain and frontal cognitive systems resulting in pr ofound executive and memory deficits, whereas more limited lesions to the basal forebrain or orbital frontal cortex will result in ''transie nt'' or ''provoked'' confabulatory responses and a more restricted pro file of cognitive deficits.