Action effect features, but not anatomical features, determine the Backward Crosstalk Effect: evidence from crossed-hands experiments.

The Backward Crosstalk Effect (BCE) indicates that response features of Task 2 in a dual-task paradigm influence even Task 1 performance. However, it can be assumed that responses are represented with multiple features in the cognitive system. In this regard, Ideomotor Theory suggests action effects as one central response feature in human action control and an earlier study by Janczyk, Pfister, Hommel, and Kunde (Cognition 132: 30-43, 2014) already provided some evidence that action effects are a crucial determinant of the BCE. The present study aimed to further investigate which response features are critical for the BCE. Therefore, a crossed-hands manipulation was implemented in two experiments to examine whether the spatial position of the actual response and thus its associated action effects or the body-side of the effectors' anatomical connection determine the BCE. Analyses revealed that even when participants press a left response key with the right hand and vice versa, the usual BCE occurs. These results indicate that the BCE depends on spatial features of the action effects rather than on anatomical features and thus provide additional support for the assumption that action effects have an important influence on the BCE and on action control in general.