Alpha oscillations and aperiodic neural dynamics jointly predict visual temporal resolution, confidence, and dependence on prior experience

Abstract

Perception requires integrating sensory input over time to construct coherent experiences. Alpha oscillations have been proposed to define the temporal resolution of perception, yet empirical evidence remains inconsistent. Here we combined a sustained visual integration paradigm with resting-state EEG to investigate how oscillatory and aperiodic neural dynamics jointly shape temporal perception. Participants (n=83) viewed alternating gratings that varied in alternation speed, producing the perception of either a fused plaid (integration) or two interchanging gratings (segregation). Faster individual alpha rhythms were associated with narrower temporal integration windows, and a steeper aperiodic spectrum predicted greater perceptual precision. Moreover, individuals with slower alpha frequencies and flatter spectra showed stronger reliance on prior judgments, suggesting reduced sensory precision and increased weighting of recent experience. Subjective confidence increased with faster alpha rhythms, reflecting the clarity of sensory evidence and its consistency with prior responses. Together, these findings show that the perceptual interpretation, confidence and previous experience effects in temporal integration reflect the joint influence of alpha rhythms and aperiodic neural activity. Mechanistically, faster alpha rhythms and lower neural noise may enhance perceptual resolution by generating more precise sampling frames per time unit, leading to finer temporal perception, reduced reliance on prior experience, and greater confidence.