Sentence comprehension and action: Effector specific modulation of the motor system

The purpose of the paper is to study whether sentence comprehension modulates the motor system. Participants were presented with 24 pairs of nouns and verbs that could be referred to hand and mouth actions (e.g., to unwrap vs. to suck the sweet), in the first block, or, in the second block, to 24 hand and foot actions (e.g., to throw vs. kick the ball). An equal number of non-sensible pairs were presented. Participants' task consisted of deciding whether the combination made sense or not: 20 participants responded by saying yes loudly into a microphone, 20 by pressing a pedal. Results support embodied theories of language comprehension, as they suggest that sentence processing activates an action simulation. This simulation is quite detailed, as it is sensitive to the effector involved. Namely, it leads to a facilitation in responses to ‘mouth sentences’ and ‘foot sentences’ compared to ‘hand sentences’ in case of congruency between the effectors – mouth and foot – involved in the motor response and in the sentence.