Autobiographical memory in Alzheimer's Disease

Retrieval of autobiographical memories (AMs) is important for “sense of self”. Current theoretical understanding of AM retrieval predicts that working memory (WM) and executive functions (ExF) enable the hierarchical search for, and reliving of past, personal events in the mind’s eye. However, there remains a lack of consensus as to the nature of the relationships between these cognitive functions and semantic and episodic aspects of AM. The present study therefore aimed to explore the associations between these variables in a sample with a wide range of ability on measures of WM, ExF, and AM.
The study incorporated a between-groups component, and a correlational component with regression and mediation modelling.
Participants with Alzheimer’s disease (n = 10) and matched healthy controls (n = 10) were assessed on measures of semantic and episodic AM search and retrieval, auditory and spatial WM, and verbal fluency.
AD group AMs were significantly less episodic in nature compared to controls. There were no significant associations between WM measures and hierarchical search of semantic AM, or episodic AM retrieval. Verbal fluency, but not WM, predicted episodic AM retrieval and mediated the effect of dementia status on episodic AM retrieval independent of age effects.
The study concluded that people with AD may be limited in their retrieval of episodic AM due to weaker verbal fluency, independent of ageing effects. WM appeared to play little role in facilitating episodic AM retrieval. Reminiscence interventions for people with AD might benefit from incorporating structured, individualised external memory-aids to facilitate more effective AM search and retrieval to prolong wellbeing.