Exploring the recollective experience during autobiographical memory retrieval in amnestic Mild Cognitive Impairment.

Abstract

Autonoetic consciousness refers to the ability to mentally transport oneself back in subjective time to relive elements of, or all, of a past event, and is compromised in the early stages of Alzheimer?s disease (AD). Here, we investigate autobiographical memory (ABM) and the recollective experience in amnestic mild cognitive impairment (aMCI). aMCI participants exhibited significant deficits compared with healthy elderly controls for both personal semantic and event detail components of ABM. These decrements were evident across all life epochs for episodic recall. Recall of an event that occurred 1 week previously, was tested in the same spatiotemporal context, and provided the greatest group dissociation, with elderly controls benefitting from a context-dependent memory effect. This reinstantiation of context did not ameliorate the anterograde deficits in the aMCI cohort, nor did it facilitate the mental reliving of these memories for either participant group. Whereas reliving judgments were comparable in both groups, aMCI participants exhibited a compromised capacity to generate vivid, self-referential visual imagery and to re-experience the original emotion of events. These contextual and experiential deficits extended beyond recently encountered events into remote epochs, and suggest a greater level of ABM impairment in aMCI than previously assumed.