Dissociable electrophysiological correlates of semantic access of motor and non-motor concepts

Sci Rep. 2019 Aug 7;9(1):11482. doi: 10.1038/s41598-019-47835-9.

Abstract

The notion of semantic embodiment posits that concepts are represented in the same neural sensorimotor systems that were involved in their acquisition. However, evidence in support of embodied semantics - in particular the hypothesised contribution of motor and premotor cortex to the representation of action concepts - is varied. Here, we tested the hypothesis that, consistent with semantic embodiment, sensorimotor cortices will rapidly become active while healthy participants access the meaning of visually-presented motor and non-motor action verbs. Event-related potentials revealed early differential processing of motor and non-motor verbs (164-203 ms) within distinct regions of cortex likely reflecting rapid cortical activation of differentially distributed semantic representations. However, we found no evidence for a specific role of sensorimotor cortices in supporting these representations. Moreover, we observed a later modulation of the alpha band (8-12 Hz) from 555-785 ms over central electrodes, with estimated generators within the left superior parietal lobule, which may reflect post-lexical activation of the object-directed features of the motor action concepts. In conclusion, we find no evidence for a specific role of sensorimotor cortices when healthy participants judge the meaning of visually-presented action verbs. However, the relative contribution of sensorimotor cortices to action comprehension may vary as a function of task goals.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alpha Rhythm / physiology*
  • Brain Mapping
  • Comprehension / physiology*
  • Evoked Potentials / physiology
  • Healthy Volunteers
  • Humans
  • Motor Cortex / diagnostic imaging
  • Motor Cortex / physiology*
  • Parietal Lobe / diagnostic imaging
  • Parietal Lobe / physiology*
  • Semantics*
  • Young Adult