The profile of prospective memory impairment in Parkinson's disease and implications for everyday functioning
- Author(s): Pirogovsky, Eva
- et al.
Prospective memory (ProM) is an aspect of episodic memory that involves remembering to perform an intended action at some designated point in the future, and is critically involved in everyday functioning. Studies suggests that ProM is dependent on the functional integrity of the frontal lobe system and associated executive functions, with time-based ProM relying more heavily on executive processes than event-based ProM. Although individuals with Parkinson's disease (PD) demonstrate impairments in executive functions and strategic aspects of episodic memory, few studies have examined ProM in PD. The present study examined ProM and the relationship between ProM and everyday functioning in 33 PD patients and 26 demographically comparable adults. PD participants were disproportionately impaired in TB ProM (Cohen's d = 1.30) compared to EB ProM (d = 0.63), committed an increased number of omission errors on TB trials, and were worse (at a trend level) than healthy older adults in retrospective memory for the contents of the intentions. TB ProM performance correlated with standardized measures of executive function, working memory, and retrospective episodic memory in PD. Taken together, these results suggest that PD participants are impaired in the executive /strategic and retrospective memory aspects of ProM. There were no significant differences between groups in strategic time monitoring or basic temporal perception, suggesting that TB ProM impairment in PD may not be related to declines in these cognitive processes. Alternatively, these findings may be related to methodological limitations of the tasks used to measure these processes in the present study. Within the PD sample, ProM deficits correlated with two performance-based measures of everyday functioning (financial capacity, medication management) and a self-report measure of medication management. Moreover, ProM impairment uniquely predicted declines on a performance-based measure of financial capacity, but not medication management, over and above other predictors of everyday functioning. Although future studies with larger samples and longitudinal designs are warranted, these results suggest that ProM may provide unique information regarding everyday functioning skills. The present findings have implications for the assessment of ProM in clinical neuropsychological evaluations and for intervention strategies aimed at improving ProM dysfunction in individuals with PD