The Association between High Neuroticism-Low Extraversion and Dual-Task Performance in Healthy Older Adults

Abstract

Personality dimensions, specifically the combined effect of high neuroticism (N)-low extraversion (E), have been related to greater odds of cognitive impairment in older adults. However their association with dual-task performance has not been examined. Because aging has a negative effect on divided attention, we examine whether individual differences in personality dimensions were related to dual-task decrements in non-demented older adults. We predicted that the combined effect of high N-low E would relate to greater dual-task costs in gait velocity and cognitive performance. Participants were healthy older adults (N = 295, age range = 65-95, female = 164) who completed the BigS inventory and a dual-task paradigm in which they were asked to: 1) walk at a "normal pace," 2) perform a serial 7's subtraction task while standing in place, and 3) walk while performing a serial 7's subtraction task. Gait velocity was obtained using an instrumented mat. Cognitive performance was assessed by calculating percent accuracy of a serial 7's subtraction task. Two separate linear mixed effects models were run to test the effect of high N-low E on repeated task performance. Personality combination (4 levels: High N-Low E, Low N-High E, High N-High E, and Low N-Low E) served as the between-subject factor, condition served as the two-level repeated within-subject factor, and gait velocity and cognitive performance served as dependent variables in models one and two, respectively. The interaction between the N-E combination groups (high N-low E group served as the reference group) and condition was included to evaluate whether the high N-low E group demonstrated greater dual-task costs compared to the low N-high E group. Results revealed that the high N-low E group incurred greater costs in both gait velocity (95% CI: --17.68 to --3.07) and cognitive performance (95% CI: --19.34 to --2.44) than did the low N-high E group. Results suggest that the combined effect of high N-low E interferes with the allocation of attentional resources to competing task demands. Thus, elders with this personality trait combination may be at higher risk for falls when engaging in concurrent tasks requiring divided attention.