RESUMEN
Embodied cognition theories predict a functional involvement of sensorimotor processes in language understanding. In a preregistered experiment, we tested this idea by investigating whether interfering with primary motor cortex (M1) activation can change how people construe meaning from action language. Participants were presented with sentences describing actions (e.g., "turning off the light") and asked to choose between two interpretations of their meaning, one more concrete (e.g., "flipping a switch") and another more abstract (e.g., "going to sleep"). Prior to this task, participants' M1 was disrupted using repetitive transcranial magnetic stimulation (rTMS). The results yielded strong evidence against the idea that M1-rTMS affects meaning construction (BF01 > 30). Additional analyses and control experiments suggest that the absence of effect cannot be accounted for by failure to inhibit M1, lack of construct validity of the task, or lack of power to detect a small effect. In sum, these results do not support a causal role for primary motor cortex in building meaning from action language.
Asunto(s)
Corteza Motora , Estimulación Magnética Transcraneal , Humanos , Estimulación Magnética Transcraneal/métodos , Corteza Motora/fisiología , Lenguaje , CogniciónRESUMEN
According to the embodied cognition view, comprehending action-related language requires the participation of sensorimotor processes. A now sizeable literature has tested this proposal by stimulating (with TMS or tDCS) motor brain areas during the comprehension of action language. To assess the evidential value of this body of research, we exhaustively searched the literature and submitted the relevant studies (N = 43) to p-curve analysis. While most published studies concluded in support of the embodiment hypothesis, our results suggest that we cannot yet assert beyond reasonable doubt that they explore real effects. We also found that these studies are quite underpowered (estimated power < 30%), which means that a large percentage of them would not replicate if repeated identically. Additional tests for excess significance show signs of publication bias within this literature. In sum, extant brain stimulation studies testing the grounding of action language in the motor cortex do not stand on solid ground. We provide recommendations that will be important for future research on this topic.