Refining cognitive dispersion metrics for brain–behavior prediction in aging and mild cognitive impairment
Journal
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring
Journal Volume
18
Journal Issue
2
ISSN
2352-8729
2352-8729
Date Issued
2026-04
Author(s)
Nguyen, Truc Tran Thanh
Abstract
INTRODUCTION: This study addresses three key issues in the standardization of cognitive dispersion: its operationalizations though intra-individual standard deviation (ISD) versus coefficient of variation (CoV), its reliability, and its dependence on the size of the neuropsychological battery. METHODS: Cognitive dispersion was calculated in 318 older adults (Mage = 70.7, 61% female). Linear regression tested whether ISD, in the context of mean cognitive performance, provided greater explanatory power than CoV for brain morphometry. We further evaluated 2-year reliability of dispersion and compared psychometric properties across four battery sizes. RESULTS: We found that ISD, modeled jointly with mean cognitive performance, was a stronger predictor of entorhinal cortex thickness than CoV, which obscured critical mean–dispersion interactions. DISCUSSION: These findings suggest that ISD, rather than CoV, offers a more valid quantification of cognitive dispersion, and that dispersion measures are most informative when derived from adequately comprehensive neuropsychological batteries.
Subjects
cognitive aging
cognitive dispersion
intra-individual variability
mild cognitive impairment
neuropsychological tests
Publisher
Wiley
Type
journal article