Rapid repetitive syllable sounds associate with episodic memory, executive function, and working memory in cognitively healthy and subjectively impaired older adults

Non-invasive screening tools for Alzheimer's disease (AD) risk are needed. Decline in episodic memory and subjective cognitive impairment (SCI) are both associated with elevated AD risk. We investigated associations between three cognitive domains (episodic memory, executive function, and working memory) and motor speech performance in older adults with healthy cognition (HC) or SCI. In total, 1014 community-dwelling participants (cross-sectional sample: 843 HC, mean 66.9 years, 72.8% female; 171 SCI, mean 66.3 years, 70.8% female) remotely completed cognitive tests (Paired Associates Learning and Spatial Working Memory from the Cambridge Neuropsychological Test Automated Battery) and motor speech tests (Tasmanian [TAS] Test). We evaluated whether acoustic motor speech features extracted from 10-s tests of "pa," "ta," or "ka" syllable repetition improved episodic memory, executive function, and working memory regression models over age, sex, education, anxiety, and depression (ΔAIC > 2). Motor speech features improved estimation of cognitive scores over fixed demographic and clinical variables in each group and cognitive domain. In summary, we found associations between motor speech performance and cognition in older adults. Short motor speech tests demonstrate potential for non-invasive, cost-effective AD risk screening. Longitudinal research is needed to investigate relationships between individual motor speech features and cognitive changes confirmed to result from the progression of AD.