Effector-specific motor activation modulates verb production.

Language comprehension studies have demonstrated that effector-specific activation of the motor system supports the representation of word meaning. The aim of the present study was to test whether motor activation is also relevant for verb production. In the first part of the experiment, participants named photographs of actions either in effector-homogeneous blocks, with all actions involving the same effector, or effector-heterogeneous blocks, with actions involving different effectors. Action-naming latencies were longer in homogeneous blocks, indicating the activation of effector information. In the second part of the experiment, the same participants named action pictures in random order, while performing a motor task with either their hand or foot. The motor task caused interference for action-picture naming: latencies were longer when the effector of the depicted action was congruent with the effector of the action used in the motor task. While these results do not exclude the existence of abstract semantic representations, they indicate that effector-specific effects found in language comprehension extend to language production.