Form constraints in motion binding.

Visual analyses of form and motion proceed along parallel streams. Unified perception of moving forms requires interactions between these streams, although whether the interactions occur early or late in cortical processing remains unresolved. Using rotating outlined shapes sampled through apertures, we showed that binding local motions into global object motion depends strongly on spatial configuration. Identical local motion components are perceived coherently when they define closed configurations, but usually not when they define open configurations. Our experiments show this influence arises in early cortical levels and operates as a form-based veto of motion integration in the absence of closure.