Tracking visual rhythms: a concert of sensory and motor simulation
Neural oscillations have been proposed to model external temporal structure by phase-coupling to environmental rhythms, thereby supporting adaptive perception. However, there is little evidence supporting these theories, particularly in the visual domain, and the underlying mechanisms remain unclear. Using MEG and a new empirical approach we addressed this issue. Participants attended 1.3 and 2 Hz visual displays of rotating Gabors and judged either the timing or content of these events. We show behaviourally-relevant rate-specific phase-coupling in motor structures to - and beyond - the visual rhythm specifically when judging temporal features of the display. We subsequently devised a rate-specific decoding measure to show that visual structures track anticipated, temporally-precise content regardless of task. This sensory simulation predicted the temporal tracking in motor structures. We consequently propose a mechanism by which automatic, temporally-specific sensory simulation yields an information envelope read out by motor areas when estimating temporal characteristics in our environment.