In the present experiments the ability of attention to modulate the perceptual dominance in ambiguous motion displays was assessed, as well as the resulting changes of the motion aftereffect (MAE). As ambiguous motion stimuli we used plaids consisting of two differently moving components, where directed attention can select one or the other of the two components. We monitored this selection process during adaptation, and then measured the resulting MAE with static and/or dynamic test stimuli. The results demonstrate that attention increased the dominance of the selected component substantially. This led to an increase in the size of the MAE to the attended component, while the MAE to the not attended component decreased. It was further shown that the attentional MAE effect was relatively short-lasting, only for about the first third of the total MAE. It is concluded that attention can access levels of motion processing that are prior to or at the level of the generation of the component MAEs.