Abstract
Acute bouts of physical exercise are known to modulate cognitive task performance (Lambourne & Tomporowski, 2010) and brain activity measured using electroencephalography (EEG; Bailey et al., 2008). However, EEG studies have largely focused on cortical oscillations in different frequency bands (alpha, beta; Brummer et al., 2011) and little is known about how acute bouts of exercise affect the temporal dynamics of information processing. To investigate this issue, we used the event-related potential (ERP) technique to measure fluctuations in the patterns of perceptual and cognitive processes measured during physical exercise. Nine participants viewed continuous rapid serial visual sequences (2Hz) of stimuli consisting of frequent non-targets (cars 80%), rare non-targets that did not require a response (faces oriented right, 10%), and rare targets (faces oriented left, 10%) that required a simple detection response. Each subject viewed the sequences under three conditions whilst sitting on a stationary bike: resting, pedaling at a low intensity (~40W power output, mean rating of perceived exertion (RPE) = 8.5), and pedaling at a higher intensity (~60% of VO2max, mean RPE = 14.1). In all conditions, EEG was recorded from 32 scalp electrodes. Analyses of the ERP data revealed that the mean amplitude of the parieto-occipital P1 component evoked by the frequent non-targets was larger during low intensity exercise compared to rest (p<.05). While the amplitude of the target evoked P3 component was not modulated by exercise, there was a marginal effect of exercise on peak latency, such that latency was reduced under high intensity exercise compared to rest (p=.055). This concurs with behavioral data which demonstrate significantly faster RTs under high intensity exercise compared to rest (p<.05). Together these results are consistent with the conclusion that exercise modulates multiple stages of information processing, ranging from post-perceptual target categorization to early stage sensory processing.
Meeting abstract presented at VSS 2014