Alpha and Beta Frequency Modulations in Motion Prediction Reveal Mechanisms of Predictive Coding in Perception

Perception is an active process guided by prior knowledge and expectations, allowing the brain to optimize sensory processing and reduce uncertainty. Although modulations in alpha (7-13 Hz) and beta (15-25 Hz) frequencies have been linked to perceptual and top-down processing, their distinct roles within the predictive coding framework remain elusive. Here, we recorded electroencephalographic activity in 60 participants before (at rest) and during a representational momentum task, where prior information of motion typically biases subsequent perceptual judgments. Within participants, instantaneous frequency modulations occurred throughout the trial. Beta-band modulations tracked the inducer's speed and participant's perceptual choices, consistent with a role in encoding predictive information about stimulus dynamics. In contrast, alpha-band frequency modulations were selectively related to perceptual outcomes in trials that elicited representational momentum, with faster instantaneous alpha frequencies associated with the absence of predictive motion extrapolation. This pattern extends previous findings suggesting that alpha frequency dynamics bias the balance between temporal integration and segregation in the context of motion extrapolation, such that faster alpha rhythms favor veridical segmentation of sensory input, whereas slower alpha rhythms promote predictive integration over time. In contrast to ongoing oscillatory activity, resting-state individual alpha and beta frequencies were not associated with the representational momentum phenomenon, indicating that dynamic, task-related frequency modulations, rather than trait-like oscillatory fingerprints, are critical for understanding predictive perceptual biases in highly dynamic contexts.