Emily Machniak^1,2, Tom Bullock^1,2, Caitlin Gregory^1,2, Julia Ram¹, Barry Giesbrecht^1,2; ¹University of California, Santa Barbara, ²Institute for Collaborative Biotechnologies

Attention can be biased by arbitrary features of the environment (e.g., color) that we have prior experience with, especially if those features are associated with reward (Anderson et al., 2011). Attention can also be impacted by our physiological state, such that a transition from rest to physical activity can impact behavior and different stages of sensory and cognitive information processing (Bullock et al., 2015). While reward and physical exercise impact overlapping attentional mechanisms, the precise interplay is not well understood. Here, we investigated the impact of physical activity on experience-biased attention. Participants (n=35) completed a continuous performance task where they monitored a sequence of images (800 ms) surrounded by colored frames and responded to infrequent images with longer durations (1200 ms). During a learning phase, participants associated one color (e.g., red) with monetary reward and another (e.g., blue) with no reward. One week later, they returned for a test phase involving the same task, but with no prospect of reward and while riding a stationary exercise bike at different intensities (low and moderate). EEG data were acquired at the scalp throughout. In the learning phase, there was a steeper decline in target detection performance over the course of the trial blocks in non-rewarded relative to rewarded trials (p<.05). During the test phase, target detection was improved for previously rewarded colors (p=.003) but, the typical change in performance over time within the blocks was not observed (p=.33). EEG time-frequency analyses were computed for correctly detected target trials. Theta oscillations (~3-7 Hz), typically associated with cognitive control, and alpha oscillations (~8-14 Hz), typically associated with selective attention, before and after the critical target period were modulated by reward and physical exercise. Together, these results suggest that physical state and reward both influence neural signatures of sustained attention.

Acknowledgements: Research was sponsored by the National Institutes of Health (R21 DA043712-01) and U.S. Army Research Office under the contract W911NF-19-2-0026 for the Institute for Collaborative Biotechnologies.