Do my hands prime your hands? The hand-to-response correspondence effect.

Previous research has shown an effect of handle-response correspondence on key-press responses when participants judged the upright or inverted orientation of photographed one-handled graspable objects. In three experiments, we explored whether this effect still holds for symmetric graspable objects that are usually grasped by two hands (i.e. two-handled objects; e.g. shears). In Experiments 1 and 2, participants were required to perform a between-hand response in order to categorize cooking or amusement objects appearing as grasped from either an allocentric (Experiment 1) or an egocentric perspective (Experiment 2). In Experiment 3, they were required to perform a within-hand response to categorize the same stimuli appearing as grasped from an egocentric perspective. Across all three experiments, results showed that categorization was more difficult when the objects were displayed as grasped on the opposite side than the response rather than on the same side. We discuss the implications of these results for theories of action potentiation and spatial coding and suggest that different mechanisms may be recruited depending on the required action (i.e. response mode).