Executive Functions are Independently Associated with Cognitive Dispersion in HIV Disease

Abstract

Objective: People with HIV (PWH) can demonstrate elevated cognitive intraindividual variability (IIV-dispersion) that is associated with everyday functioning problems. Higher IIV-dispersion is theorized to reflect lapses in executive aspects of cognitive control, but few studies have directly evaluated this possibility.

Method: 72 PWH completed the Cogstate and clinical measures of executive functions, psychomotor speed, and episodic memory. IIV-dispersion was calculated with the coefficient of variation (CoV) from six age-adjusted Cogstate subtest scores.

Results: Multiple regression showed that the three domain-level cognitive predictors explained 8% of the variance in Cogstate CoV (p = .03). Within this model, poorer executive functions were moderately associated with higher Cogstate CoV (p = .01), but the psychomotor and episodic memory domains were not (ps > .05).

Conclusions: Findings align with cognitive theory in demonstrating IIV-dispersion is uniquely associated with independent measures of executive functions among PWH. Future experimental and mechanistic studies are needed to determine the precise executive aspects of IIV-dispersion.

Keywords: Cognitive flexibility; Infectious disease; Neuropsychological assessment; Psychometric; Within-subject variation.