Abstract
Purpose :
Animal models indicate that physical exercise can enhance neuroplasticity in the visual cortex. However, exercise and neuroplasticity studies involving humans have reported conflicting results. We tested the hypothesis that interleaving short periods of exercise with the perceptual learning protocol would enhance the rate and magnitude of learning relative to a non-exercise control condition.
Methods :
Healthy participants (n = 32) were randomly assigned to an Exercise or Non-exercise intervention group. In each of 5 consecutive daily sessions, participants alternated between either cycling on a stationary bicycle (Exercise) or watching a video (Non-exercise) and a perceptual learning task. Pre- and post-measures were taken before and after the first and last perceptual learning sessions. This perceptual learning task involved the participant discriminating a peripheral target letter (4° vertically from fixation) that was surrounded in the cardinal axes by 4 distractor letters. Task difficulty was increased/decreased by reducing/increasing the spacing between the distractors and target respectively. Fixation was monitored with an infrared eye tracker during the task. Each component (cycling/video/perceptual learning task) was 5 minutes, and the alternating set was repeated 6 times for a total of 1 hour. Additionally, the Exercise group were required to maintain a heartrate that corresponded to their performance on a moderate load step-test while cycling.
Results :
Peripheral crowding performance (the ratio of letter-spacing to letter-size) was decreased (improved) significantly in both the Exercise (Pre = 2.24, Post = 1.59, V = 134, p < 0.001) and the Non-exercise (Pre = 2.20, Post = 1.73, V = 122, p = 0.003) groups. However, a Mann-Whitney U test did not show a statistical difference between the pre-post difference of the two groups W = 112, p = 0.564.
Conclusions :
Perceptual learning of a peripheral crowding task occurred in both Exercise and Non-exercise groups. However, the interleaved exercise intervention did not influence perceptual learning, indicating no change in visual cortex neuroplasticity.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.