Saccades are phase-locked to alpha oscillations in the occipital and medial temporal lobe during successful memory encoding

Efficient sampling of visual information requires a coordination of eye movements and ongoing brain oscillations. Using intracranial and magnetoencephalography (MEG) recordings, we show that saccades are locked to the phase of visual alpha oscillations and that this coordination is related to successful mnemonic encoding of visual scenes. Furthermore, parahippocampal and retrosplenial cortex involvement in this coordination reflects effective vision-to-memory mapping, highlighting the importance of neural oscillations for the interaction between visual and memory domains.Author summary: In everyday life, we constantly move our eyes to sample visual information. In order to make the sampling efficient, these eye movements need to be coordinated with the intrinsic brain dynamics that constrain visual computations. The present study provides novel evidence for how this coordination is achieved at the neuronal level, from 2 independent data sets: direct brain recordings in epileptic patients and noninvasive magnetoencephalography recordings in healthy participants. Both studies showed that eye movements are locked to the phase of alpha oscillations—synchronous and coherent neuronal electrical activity at 7–14 Hz—just prior to a saccade, i.e., a rapid eye movement that abruptly changes the point of fixation. Importantly, this coordination is predictive of successful memory encoding.