Deling He, Ph.D.
Postdoctoral Research Associate
CCANDL Lab
Department of Communication Sciences and Disorders
University of Wisconsin–Madison
Validation of In-Person and Remote Semantic Fluency Assessment and Its Sensitivity to Subtle Cognitive Impairment and Plasma p-tau217 Positivity
Alzheimer’s disease (AD) and related dementias (ADRD) are a growing global public health challenge. More than 55 million people worldwide currently live with ADRD, a number projected to nearly triple by 2050. There is a critical need for accessible, low-burden, and sensitive tools that can complement traditional clinical assessments and enable large-scale screening in community settings. Mobile and digital assessments, particularly remote and self-administered tools, are increasingly being explored to meet this need. To advance this effort, our lab developed TalkTracker, a tablet-based application designed to collect speech samples remotely and repeatedly in the home environment. The current study focused on an action semantic fluency task administered weekly over eight weeks. We examined whether language-derived measures from action fluency, including total correct responses, age of acquisition (AoA), and word frequency, were associated with cognitive status and plasma p-tau217 positivity, a hallmark biomarker of AD pathology. We examined these associations both cross-sectionally using linear regression models and longitudinally using linear mixed-effects models, adjusting for age, sex, and education. Additionally, we assessed the test-retest reliability of remotely collected action fluency measures using intraclass correlation coefficients (ICCs) and evaluated convergent validity with in-person semantic fluency performance using available animal fluency collected closest in time to the mobile assessment. Pearson correlations, ICCs, and Bland-Altman analyses were conducted. Findings from this study will inform the utility of remotely administered action semantic fluency as a reliable and scalable digital biomarker for cognitive monitoring and the early detection of AD-related cognitive decline.
Funding
Principal Investigator: Kimberly D. Mueller. This work is supported by R01 AG082052 ; R01 AG054059; P30 AG062715; P50 AG033514; RF1 AG027161/R01 AG027161.