Cortical alpha rhythms interpolate occluded motion from natural scene context.

Tracking objects as they dynamically move in and out of sight is critical for parsing our everchanging 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 person's 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 based on the contextual cues from the surrounding environment.NEW & NOTEWORTHY Inferring how objects continue to move during occlusion requires contextual cues from the surrounding environment. Such contextual information is incorporated via neural feedback linked to cortical alpha oscillations. Here, we demonstrate that alpha dynamics track the predicted movement of a person during occlusion, depending on scene context: Alpha oscillations not only track how the person moves when their path is unobstructed but also when they need to stop because of obstacles blocking their way.