Separated hands further response-response binding effects.

Action control is hierarchically organized. Multiple consecutive responses can be integrated into an event representation of higher order and can retrieve each other upon repetition, resulting in so-called response-response binding effects. Previous research indicates that the spatial separation of responses can affect how easily they can be cognitively separated. In this study, we introduced a barrier between the responding hands to investigate whether the spatial separation of two responses also influences response-response binding effects. In line with previous research on stimulus-response binding, we expected an increased separability of responses to result in stronger response-response binding effects when responding hands were separated by a barrier. We indeed found stronger response-response binding effects with separated hands. Results indicate that a more distinct representation of individual actions through increased separability might benefit the control of hierarchical actions.