Confabulation, Executive Functions, and Source Memory in Alzheimer's Disease

Abstract Most current views consider confabulation strictly related to the dysfunction of frontally based processes subserving the control of retrieval from long-term memory. This study addresses the relationship between confabulation, source memory, and executive functions in 17 Alzheimer disease (AD) patients and 18 normal controls. The following tasks were used: Six tasks tapping executive functions; a task in which subjects had to discriminate the origin of a given information, i.e. visual perception or imagination; a modified version of the Confabulation Battery (Dalla Barba, 1993a) tapping episodic memory, general semantic memory and personal plans; and a modified version of the Crovitz test, in which, in response to a cue word, subjects had to produce a personal memory, a general semantic memory, or a personal plan. AD patients were clearly impaired on tests of executive functions, and showed poor monitoring abilities for the source of information. AD patients confabulated when they were required to retrieve a personal episode and also, although less frequently, when they were required to make a personal plan. Correlation studies showed that AD patients' confabulation did not correlate with their performance on executive tasks or with their ability to discriminate the origin of information. It is suggested that confabulation reflects a pathological awareness of personal temporality.