Associations among response time inconsistency, attention switching, and cognitive status: A measurement burst approach.

OBJECTIVE: Trial-to-trial variability in response times (RT inconsistency; RTI) has emerged as an important dimension of performance for characterizing cognitive function and cognitive status. The present study explores whether (a) RT inconsistency is associated with attention switching performance between-persons and within-persons over time, (b) RTI-attention switching associations differ as a function of cognitive impairment status, and (c) RTI-attention switching associations change longitudinally over 4 years. METHOD: A sample of 304 adults (64-92 years) at baseline completed measures of attention switching and a 1-back choice response time task weekly for 4-5 weeks, repeating this protocol and a basic neuropsychological assessment annually for 4 years. Three cognitive status subgroups were identified at baseline: healthy controls (HC), as well as cognitive impairment-no dementia (CIND) status based upon single (CIND-S) and multiple (CIND-M) domains. RESULTS: Greater RTI was associated with significantly slower attention switching performance between-persons and within-persons over time. Importantly, RTI-attention switching associations were specific to individuals exhibiting cognitive impairment. Specifically, within-person associations were evident among CIND-M participants, while between-person associations emerged for CIND-S and CIND-M participants. RTI-attention switching associations did not reliably change over time. All associations were independent of age, education, chronic health conditions, and mean RT. CONCLUSIONS: RTI confers a unique information about cognitive function and status and holds promise as a functional indicator of pathological cognitive aging. (PsycInfo Database Record (c) 2026 APA, all rights reserved).