Motor intrusion errors as a novel marker of neurodegeneration and executive dysfunction in Alzheimer's disease

Objective: With the development of disease-modifying therapies for Alzheimer's disease, continued clarification of clinical indicators of disease progression is needed. Based on prior observations of motor intrusion errors in amyloid-positive individuals, we sought to characterize differences in clinical, cognitive, and neuroimaging variables between amyloid-positive participants with and without motor intrusions. Method: We examined 284 amyloid-positive participants with mild cognitive impairment or mild dementia evaluated within a multidisciplinary memory clinic setting. Participants with and without motor intrusion errors were compared across neuropsychological performance variables while controlling for demographic, clinical, and neuroimaging factors. Results: Participants with motor intrusion errors demonstrated indicators of more progressed disease on clinical and neuroimaging markers. After controlling for these variables, greater executive dysfunction was observed in participants with motor intrusions with effect sizes ranging from small (η_p² = .02) to medium (η_p² = .12). Differences in performances on memory, naming, and basic processing speed tasks were not observed between the groups. Conclusions: Overall, the results of the present study suggest that the presence of a motor intrusion error may be associated with greater clinical impairment and, more specifically, executive dysfunction in Alzheimer's disease. (PsycInfo Database Record (c) 2026 APA, all rights reserved).