Twists and Oliver Twists in Mental Rotation: Complementary Actions as Orphan Processes

A growing body of work shows that compatible actions executed in parallel with cognitive tasks contribute beneficially to cognition, compared to incompatible actions. We investigate how such complementary actions are generated. Two models from imitation research, Associated Sequence Learning (ASL) and Active Intermodal Matching (AIM), were extended to develop models of complementary action generation. ASL postulates a general generation process based on learning, whereas AIM postulates a specialist process. Using a mental rotation task where participants tended to spontaneously generate parallel actions, we conducted two experiments to test the predictions of the extended models. Surprisingly, the results show that when compared to no-actions, complementary actions do not improve accuracy. The two experiments do not provide clear validation for either model of generation, but there is more support for the generalist model than the specialist one. We propose a revision to the generalist model based on this trend.