Rhythmic information sampling in the brain during visual recognition

Several studies observed behavioral oscillations in perceptual sensitivity across stimulus presentation time, and these fluctuations have been linked to oscillatory processing in the brain. However, whether specific brain areas show oscillations across stimulus time (i.e., oscillatory sampling) has not been investigated. Here, we randomly revealed features of face images across time and recorded participants’ brain activity using magnetoencephalography (MEG) while they performed two recognition tasks. This allowed us to quantify how each snapshot of visual information coming from the stimulus is processed across time and across the brain. Oscillatory sampling was mostly visible in early visual areas, at theta and low beta frequencies. Furthermore, it explained a larger part of brain activity than oscillatory processing. Other parts of the brain showed distinct sampling patterns. These results advance our understanding of the oscillatory neural dynamics associated with visual processing and show the importance of considering the temporal dimension of stimuli when studying visual recognition.