Object-Relevant Kinematics Influence Imitative Compatibility
Killingsworth, Stefanos Sherif
One critical finding from the literature on embodied cognition is that people produce actions more efficiently when observing similar as compared to when observing different actions. This imitative compatibility effect has been typically studied with simple actions that have minimal ecological validity. The present dissertation presents five experiments that investigate how these compatibility effects are altered when participants produce actions with a familiar object (key pad), but view objectless actions made by an onscreen model hand. The mismatch in object directedness between observed and produced actions was adopted (1) to investigate whether compatibility effects are even possible when there is such a mismatch and, if possible, (2) to investigate how objects influence compatibility effects. The experiments here demonstrate that it is possible to obtain a compatibility effect under the mismatch conditions and reveal a compatibility specificity effect, in which flexions motions (curling of the fingers typical of a key press action) generate compatibility effects, but extension motions (straightening of the finger away from the palm) do not. Five experiments narrow the various components of participant motions for which compatibility effects may be specific and isolate particular kinematic patterns (i.e. extensions versus flexions) as a plausible cause for the observed specificity. These results broaden our understanding of compatibility effects and about links between action perception and production more generally. Furthermore, these results demonstrate that studies of human action can benefit from expanding their investigations beyond the connections between movement processing involved in action perception and production into how the relevant representations of action are situated within the action-environment interface. Finally, these findings may have important connections to other findings in the embodied cognition literature suggesting that perceiving a familiar object facilitates producing motions that are typical for using the object.