Neural and Cardiac Contributions to Perceptual Suppression During Cycling

Exercise influences visual processing and is accompanied by neural and physiological changes in the body. Yet, the underlying mechanisms by which neural and physiological responses to exercise impact ensuing perception remain poorly understood. In particular, the effects of exercise-induced cardiac changes on visual perception and electrophysiological activity are unclear. Here, we aimed to investigate the relationship between conscious visual perception, neural activity, and cardiac responses during exercise. Thirty healthy participants performed a perceptual suppression task while engaging in light-intensity stationary cycling, with EEG and ECG activity recorded simultaneously. Our study shows that the probability of perceptual suppression decreased during cycling. Parieto-occipital alpha amplitudes (8-12 Hz) also decreased during cycling, but this reduction did not correlate with the decrease in perceptual suppression. Additionally, cycling decreased heartbeat-evoked potential (HEP) amplitudes, indicating altered neural processing of cardiac signals during exercise. However, these exercise-induced changes in HEP amplitudes did not predict perceptual outcomes. Moreover, changes in heart rate in response to cycling did not correlate with changes in perceptual suppression rates, pre-random dot motion stimulus alpha, or HEP amplitudes. These findings indicate that while exercise modulates conscious visual perception, the associated changes in alpha activity, heart rate, and HEPs do not fully explain this effect. Our results highlight the complex relationship between interoceptive processing and mechanisms underlying the perception of external stimuli during exercise.