Neural Oscillatory Signatures of Predictive Processing in Visual Statistical Learning.

Several studies suggest that neural oscillations play a role in cognition, including predictive processing. Recent models propose that backward alpha-band traveling waves reflect top-down predictions, while forward waves may reflect bottom-up prediction errors. We tested this hypothesis using a visual statistical learning task in which participants (N = 31) detected target shapes presented with varying levels of predictability. Electrophysiological activity and pupillometry were recorded throughout the task. Behavioral results showed faster responses for predictable targets, and pupil dilation increased for unexpected shapes. Evoked response potential analyses revealed predictability effects on the P300 component across occipital and frontal electrodes, along with modulation of alpha oscillations. However, traveling wave analyses did not show a clear effect of predictability between conditions. Instead, wave patterns showed a modest association with individual differences in cognitive strategy, with stronger top-down alpha-band waves in participants who relied more on statistical regularities. Overall, these findings challenge the view that alpha-band traveling waves implement predictive coding during visual perception, suggesting instead that they may reflect more general cognitive strategies rather than specific predictive processes.