Semantic Representation in the Mirror Neuron System

Abstract

The mirror neuron system is a fronto-parietal network of neurons that is activated both when a person performs an action and when he or she observes that action. The goal of this study was to investigate the semantic representation in this system during action language and gesture processing. This was done in a set of two behavioral experiments. Experiment 1 employed a simple priming paradigm—subjects viewed videos of symbolic gestures or landscapes, which served as the prime, followed by a word that was congruent or unrelated to the video prime, or a pseudo-word. The subject performed a lexical decision task on the target word. The study found a significant priming effect for semantically congruent target words, relative to semantically unrelated target words. However, this same priming effect was found for the video primes of landscapes. In experiment 2 we aimed to determine whether the videos were primed through effector-specific means, that is, whether hand and arm gestures would activate mirror neurons somatotopically and lead to different priming results when comparing hand responses to foot responses. We used the same priming study as experiment 1 except that subjects made their lexical decision responses on a foot pedal rather than a keyboard. Results suggest that symbolic gestures prime in a very diffuse way, such that semantic priming occurs independent of the effector being used to respond.