Rhythmic brain-behavior coupling in the visuo-motor system: theta-band coherence links saccades and oculomotor brain regions

To ensure stable visual perception, the brain requires sensorimotor integration. A propsed top-down predictive model for this integration is the internal forward model, which previously has been suggested to operate rhythmically in the theta frequency band. This study examined how rhythmic brain activity coordinates with eye movements during smooth pursuit. We recorded magnetoencephalography and eye movement data from 22 participants performing a continuous smooth pursuit task. Saccades showed a preferred intersaccadic interval of 150–300 ms, corresponding to the theta band. Coherence analyses revealed significant coupling between eye-movement related measures (target position, eye velocity) and cortical activity in key oculomotor regions. Lateralization of effects varied by eye movement direction. The networks localized by our coherence analysis correspond to those identified in fMRI studies. Furthermore, our findings show low-frequency stimulus-driven cortical activity (0–2 Hz) in sensorimotor areas and saccade-related coherence between the eye velocity signal (theta band) and V5 and parietal activity. Eye velocity also showed alpha-band coherence with brain activity in visual areas, potentially optimizing neural excitability and perception. Together, these results indicate a rhythmic top-down regulation of saccades during pursuit, linked to theta activity in posterior hubs of the oculomotor network.