Acute aerobic exercise benefits allocation of neural resources related to selective attention

Figure 1. Schematic illustration of the selective attention task used in the study. Participants were presented with high and low spatial frequency (SF) Gabor gratings in each of the two runs. In an "attend high SF run," participants detected targets of slightly higher SF than corresponding high SF standards. In an "attend low SF run," participants detected targets of slightly lower SF than corresponding low SF standards. Detecting targets of particular SF was assumed to demand directing more attentional resources to standards of corresponding SF (attended standards) than for standards of distinct SF (unattended standards). The difference between attended and unattended standards was the main contrast of interest in the neural data analyses. Each trial started with a fixation dot followed by the stimulus and an instruction to respond. Participants responded with one finger to targets and another to non-target stimuli.

Figure 2. The study diagram.

Figure 3. Time course and topographies of the spatiotemporal cluster showing a significant main effect of TASK (attended vs. unattended stimuli) at both pre-test runs, i.e., before the experimental EX or REST protocols. As expected, attended stimuli evoked significantly stronger neural activation in a widely distributed spatiotemporal cluster starting around 90 ms after stimulus onset. There were no significant clusters with relatively stronger neural activation for unattended stimuli.

Figure 4. Left Top: Topography of strongest neural difference activities between attended and unattended stimuli in both baseline runs (i.e., before exercise and before rest). An occipito-parietal region of interest was defined by estimated neural sources showing at least 50% of the maximal difference. Effects remained qualitatively identical when regions of interest with 60%, 70%, or 80% of the maximal difference were chosen (small topography shows 80% region of interest) and when taking into consideration the overall difference between attended and unattended stimuli (i.e., before and after exercise and rest). Bottom: Time courses of the global power of estimated neural activities within the bilateral occipito-parietal regions of interest as defined above (difference > 50%) for the Exercise (left) and Rest (right) conditions. Based on a sliding window analysis of neural activity within these regions of interest, attended stimuli (blueish colors) evoked stronger neural activity than unattended stimuli (reddish colors) before (bright colors) and after (dark colors) the protocols, starting around 90 ms after stimulus onset in the left hemisphere. Right Top: Relative change of neural…

Figure 5. left: Topography (back view) of the spatiotemporal cluster showing a significant 3-way PROTOCOL*TIME*TASK interaction at bilateral occipito-parietal cortex regions between 380 and 590 ms. Center: In this cluster, independent of TIME (pre/post) or PROTOCOL (exercise/rest), attended stimuli evoked stronger neural activity than unattended stimuli (i.e., the main effect of TASK). Right: While the pre-test (“normal”) relation of neural activity (i.e., attended > unattended) became relatively strengthened after exercise (i.e., a relatively stronger increase of attended compared to unattended), this relation decreased after rest. Error bars denote 95% confidence intervals.