Effects Of Moderate-intensity Aerobic Exercise On Cognition And Arousal In Extrovert/introvert Personality Types

Abstract

Aerobic exercise has been demonstrated to benefit cognitive function in many different exercise-cognition studies, however, results have been mixed. One potential moderating factor may be personality type, since differing baseline levels of cognitive arousal between Extrovert (E) and Introvert (I) personality types have been demonstrated using Eysenck’s Personality Questionnaire-Revised, as well as differing responses to physiological arousal from exercise. PURPOSE: To examine whether or not there are differences in cognitive function between E and I personality types during performance of an executive function task at rest (R) and during exercise (EX). METHODS: A flanker task was selected to evaluate cognitive function using the event-related potentials (ERP); specifically, N100 amplitude (AMP, μV) and latency (LAT, ms) as well as behavioral measures, including accuracy (ACC, % correct) and reaction time (RT, ms). Task modality was defined as easy or congruent (CON) or more difficult or incongruent (INC). Healthy students, ages 18-30 (22F and 7M), participated in the study (15E and 14I). Cognitive effort was measured at R and during 20 minutes of moderate-intensity EX performed on a stationary bicycle ergometer. Mixed-design ANOVAs were conducted to measure differences between E and I groups and across R and E conditions. RESULTS: There were no significant differences between E and I groups for any ERP or behavioral measures. Examining differences in R and E conditions revealed the following significant findings: AMP CON: R -3.54 μV ± 1.53 vs E -2.57 μV ± 1.55, p<.001; AMP INC: R -3.86 μV ± 1.83 vs E -2.93 μV ± 1.93, p <.05; RT CON: R 389.31 ms ± 44.69 vs E 362.76 ms ± 42.07, p<.001; and RT INC: R 460.87 ms ± 49.14 vs E 419.47 ms ± 47.58, p<.05. For the entire sample, cognitive benefits were more pronounced during EX for INC than CON, shown by 8.9% faster RT for INC compared to only 6.8% faster RT for CON, p < .001. Regarding the main effect of condition, there were significant improvements during exercise, with significantly decreased AMP: R -3.70 μV ± 0.32 vs EX -2.75 μV ± 0.27 p <.001, concurrent with significantly reduced RT: R 425.18 ms ± 8.39 vs EX 391.02 ms ± 8.18, p <.001. CONCLUSION: In summary, an acute bout of 20 minutes of aerobic exercise can result in significant gains in cognitive function independent of E or I personality type.