Memory awareness profiles differentiate mild cognitive impairment from early-stage dementia: evidence from assessments of performance monitoring and evaluative judgement

Abstract

Background: Measures of memory awareness based on evaluative judgement and performance monitoring are often regarded as equivalent, but the Levels of Awareness Framework suggests they reflect different awareness phenomena. Examination of memory awareness among groups with differing degrees of impairment provides a test of this proposition.

Method: Ninety-nine people with dementia (PwD), 30 people with mild cognitive impairment (PwMCI), and their relatives completed isomorphic performance monitoring and evaluative judgement measures of memory awareness and were followed up at 12 and (PwD only) 20 months. In addition to the resulting awareness indices, comparative accuracy scores were calculated using the relatives' data to establish whether any inaccuracy was specific to self-ratings.

Results: When making evaluative judgements about their memory in general, both PwD and PwMCI tended to overestimate their own functioning relative to informant ratings made by relatives. When monitoring performance on memory tests, PwD again overestimated performance relative to test scores, but PwMCI were much more accurate. Comparative accuracy scores indicated that, unlike PwD, PwMCI do not show a specific inaccuracy in self-related appraisals.

Conclusions: The results support the proposition that awareness indices at the levels of evaluative judgement and performance monitoring should be regarded as reflecting distinct awareness phenomena.