Language-induced motor activity in bi-manual object lifting.

Language comprehension requires a simulation process that taps perception and action systems. How specific is this simulation? To address this question, participants listened to sentences referring to the lifting of light or heavy objects (e.g., pillow or chest, respectively). Then they lifted one of two boxes that were visually identical, but one was light and the other heavy. We focused on the kinematics of the initial lift (rather than reaching) because it is mostly shaped by proprioceptive features derived from weight that cannot be visually determined. Participants were slower when the weight suggested by the sentence and the weight of the box corresponded. This effect indicates that language can activate a simulation which is sensitive to intrinsic properties such as weight.