Parkinson’s disease (PD) and Parkinson’s Disease Dementia/Dementia with Lewy Bodies (PDD/DLB) have been associated with cognitive deficits and everyday action impairment (EAI; e.g., problems with meal preparation). EAI has been linked to numerous grave consequences; however, to date, there is no consensus for a model of EAI that would inform therapies for PD or PDD/DLB. This study aims to elucidate the causal mechanisms for EAI in these syndromes to inform future interventions.
Sixty participants will be recruited: 20 with PD without dementia, 20 with mild PDD/DLB, and 20 with mild Alzheimer’s disease (AD). Participants will be videotaped while they perform a series of everyday tasks, including coffee making, preparing a lunch, and so on. Task performance will be scored using a comprehensive taxonomy of possible errors, such as the omission of task steps or the commission of inaccurate actions (i.e., performing task steps in the wrong sequence, using inappropriate objects to perform task steps, etc.). Additionally, all participants will be asked to complete tests assessing everyday task knowledge and other cognitive processes. Performance on the everyday tasks will be compared across the groups, and the relations among neuropsychological processes and task performance variables will be evaluated.
The results will inform behavioral interventions for everyday functioning in PD and PDD/DLB. We hypothesize that people with PD and PDD/DLB have preserved everyday task knowledge, but experience EAI due to deficient cognitive control over task knowledge and performance. If our hypotheses are confirmed, then we will test whether interventions designed specifically to increase cognitive control over action are more efficacious than more general, atheoretical intervention approaches to improving functioning.
We expect that PD patients will show mild EAI relative to PDD/DLB or AD patients. However, PD and PDD/DLB patients will show a markedly different pattern of EAI than AD patients, because these syndromes are associated with different cognitive deficits. Specifically, PD and PDD/DLB patients will show relatively preserved task knowledge but more everyday errors due to cognitive control failures than AD patients. Additionally, measures of specific cognitive processes will be differentially correlated with EAI patterns.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
Recruitment and final data analysis are still ongoing, but initial findings from Dr. Giovannetti suggest that people with PD, PD dementia or AD demonstrate differences in the level and pattern of impairment of everyday actions.