Short-Term Upper Limb Immobilization Affects Action-Word Understanding
The present study aimed to investigate whether well-established associations between action and language can be altered by short-term upper limb immobilization. The dominant arm of right-handed participants was immobilized for 24 hours with a rigid splint fixed on the hand and an immobilization vest restraining the shoulder, arm, and forearm. The control group did not undergo such immobilization. In 2 experiments, participants had to judge whether a verb involved movements of the hands or feet. In Experiment 1, the response times for controls were shorter for hand-action verbs than for foot-action verbs, whereas there was no significant difference in the immobilized group. Experiment 2 confirmed these results with a pre/posttest procedure. Shorter response times were shown for hand-action verbs than for foot-action verbs in the pretests and posttests for the control group and in the pretest for the immobilized group (i.e., before immobilization). This difference was not observed for participants undergoing 24 hr of hand immobilization, who showed little progress in assessing hand-action verbs between pretest and posttest. Moreover, participants with the highest motor imagery capacities clearly demonstrated shorter response times in Experiment 2 for both hand-action and foot-action verbs, regardless of hand immobilization. Overall, these findings demonstrate for the first time that short-term sensorimotor deprivation can affect action verb processing. We discuss our results in light of the embodiment view, which considers that cognition is grounded in sensorimotor experiences.