Interwoven functionality of the brain’s action and language systems

Theories of embodied cognition consider language understanding as intimately linked to sensory and motor processes. Here we review evidence from kinematic and electrophysiological studies for the idea that processing of words referring to bodily actions, even when subliminally presented, recruits the same motor regions that are involved in motor control. We further discuss the functional role of the motor system in action word retrieval in light of neuropsychological data showing modulation of masked priming effects for action verbs in Parkinson’s patients as a function of dopaminergic treatment. Finally, a neuroimaging study revealing semantic somatotopy in the motor cortex during reading of idioms that include action words is presented. Altogether these findings provide strong arguments that semantic mechanisms are grounded in action-perception systems of the brain. They support the existence of common brain signatures to action words, even when embedded in idiomatic sentences, and motor action. They further suggest that motor schemata reflecting word meaning contribute to lexico-semantic retrieval of action words.