Cortical alpha rhythms interpolate occluded motion from natural scene context

Abstract

Tracking objects as they dynamically move in and out of sight is critical for parsing our ever-changing real-world surroundings. Here, we explored how the interpolation of occluded object motion in natural scenes is mediated by top-down information flows expressed in cortical alpha rhythms. We recorded EEG while participants viewed videos of a person walking across a scene. We then used multivariate decoding on alpha-band responses to decode the direction of movement across the scene. In trials where the person was temporarily occluded, alpha dynamics interpolated the persons predicted movement. Critically, they did so in a context-dependent manner: When the scene context required the person to stop in front of an obstacle, alpha dynamics tracked the termination of motion during occlusion. As these effects were obtained with an orthogonal task at fixation, we conclude that alpha rhythms automatically interpolate occluded motion in a context-dependent way.