Interindividual and intraindividual variability in amnestic mild cognitive impairment (aMCI) measured with an online cognitive assessment
Date
2021
Authors
LaPlume, Annalise A.
Paterson, Theone S. E.
Gardner, Sandra
Stokes, Kathryn A.
Freedman, Morris
Levine, Brian
Troyer, Angela K.
Anderson, Nicole D.
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Clinical and Experimental Neuropsychology
Abstract
Introduction: Mean cognitive performance is worse in amnestic mild cognitive impairment
(aMCI) compared to control groups. However, studies on variability of cognitive performance in
aMCI have yielded inconclusive results, with many differences in variability measures and
samples from one study to another.
Methods: We examined variability in aMCI using an existing older adult sample (n=91; 51 with
aMCI, 40 with normal cognition for age), measured with an online self-administered
computerized cognitive assessment (Cogniciti’s Brain Health Assessment). Our methodology
extended past findings by using pure measures of variability (controlling for confounding effects
of group performance or practice), and a clinically representative aMCI sample (reflecting the
continuum of cognitive performance between normal cognition and aMCI).
Results: Between-group t-tests showed significantly greater between-person variability
(interindividual variability or diversity) in overall cognitive performance in aMCI than controls,
with a small to moderate effect size, d = 0.44. No significant group differences were found in
within-person variability (intraindividual variability) across cognitive tasks (dispersion) or
across trials of a response time task (inconsistency), which may be because we used a sample
measuring the continuum of cognitive performance. Exploratory correlation analyses showed
that a worse overall score was associated with greater inter- and intraindividual variability, and
that variability measures were correlated with each other, indicating people with worse cognitive
performance were more variable. Discussion: The current study demonstrates that self-administered online tests can be used to
remotely assess different types of variability in people at risk of Alzheimer`s. Our findings show
small but significantly more interindividual differences in people with aMCI. This diversity is
considered as ‘noise’ in standard assessments of mean performance, but offers an interesting and
cognitively informative ‘signal’ in itself.
Description
We would like to acknowledge the following individuals’ contributions: Michael
Meagher assisted with preparation of the CABHI grant application and provided project
management. Caitlin Johnston provided project management for data collection. Brintha Sivajohan, Komal Shaikh, Rebecca Trossman, and Rachel Downey conducted participant
assessments.
Keywords
mild cognitive impairment (MCI), cognition, episodic memory, online tests, intraindividual variability, individual differences
Citation
LaPlume, A. A., Paterson, T. S. E., Gardner, S., Stokes, K. A., Freedman, M., Levine, B., Troyer, A. K., & Anderson, N. D. (2021). “Interindividual and intraindividual variability in amnestic mild cognitive impairment (aMCI) measured with an online cognitive assessment.” Journal of Clinical and Experimental Neuropsychology, 43(8), 796–812. https://doi.org/10.1080/13803395.2021.1982867