Episodic memory decline is associated with deficits in coherence of discourse

This study investigates coherence of discourse in the production of autobiographical narratives by individuals with aMCI. Autobiographical interviews were analyzed to determine whether reduced episodic recall was related to deficits in discourse coherence. A coherence rating scale was used to evaluate relatedness of the autobiographical details produced by participants to the topic of discourse. Interviews were transcribed, segmented into details, and divided into sets of episodic, semantic, or supplementary information, which were subsequently analysed with the coherence rating scale. We predicted that the known episodic deficits observed in aMCI could also affect the retrieval of coherent episodic information. The results revealed deficits in coherence could be found in both episodic and semantic information in the aMCI group. These results suggest that the cognitive deficits experienced by individuals with aMCI may go beyond their known difficulty in recalling episodic details, as they also affect the controlled retrieval of both episodic and semantic information.

Memory awareness disruptions in amnestic mild cognitive impairment: comparison of multiple awareness types for verbal and visuospatial material

Successful memory is normally accompanied by explicit awareness of retrieval and confidence in the accuracy of the retrieval product. Prior findings suggest that these features of metamemory can be dissociated from retrieval accuracy in Amnestic Mild Cognitive Impairment (aMCI). However, the literature on this question contains variable and conflicting results, likely because of differences in experimental conditions. We sought to systematically evaluate memory awareness disruptions in aMCI using multiple measures and stimulus formats within the same individuals. Memory awareness was tested with global predictions and postdictions, judgments of learning, confidence level ratings, and modified feeling-of-knowing ratings in tasks of visuospatial and verbal memory. These tests were administered to 14 individuals with aMCI and 15 healthy, age-matched controls. Memory awareness accuracy was calculated as the correspondence between subjective judgments and memory performance.Individuals with aMCI demonstrated impaired global and trial-level retrospective task awareness for visuospatial and verbal stimuli. Additionally, modified feeling-of-knowing awareness was impaired selectively for verbal stimuli. Statistical effect sizes for global awareness impairments were comparable to impairments in several objective neuropsychological memory assessments.Memory awareness (metamemory) disruptions in aMCI were most evident for a subset of subjective judgment types and task input modalities. These findings advance understanding of the nature of memory impairments in aMCI and support the utility of incorporating memory awareness testing to better characterize memory integrity in older adults.