Purpose While physiological studies suggest specialised high-level mechanisms for the various components of optic flow, attendant behavioural evidence is lacking. We studied the motion aftereffect (MAE) induced by adaptation to complex patterns of motion formed from local components differing only in orientation. Method The MAE was measured in a 2AFC direction discrimination task where the speed of a test pattern was varied by a staircase to null the MAE. Results Rotational and radial MAEs were largest and transfered to unadapted regions of the stimulus. Conclusions. Local motion signals are combined to represent complex palterns of motion by high-level mechanisms with properties distinct from the low-level mechanisms that support them. Supported by EY04885,EY01319,EY04440.