Lateralized modulation of beta-band power in sensorimotor areas during action observation.

Joachim Lange,Alfons Schnitzler,Anastasia Pavlidou

doi:10.3389/fnint.2015.00043

Abstract

The cortical network for action observation includes areas of the visual cortex and non-visual areas, including areas of the motoric system. Parts of this network are known for their contralateral organization during motion execution, i.e., they predominantly control and respond to movements of the contralateral body side. We were interested whether this lateralized organization was also present during action observation. Human participants viewed point-light displays of human actors, where the actor was facing and moving either to the right or to the left, while participants' neuromagnetic activity was recorded using magnetoencephalography (MEG). We found that right and left facing movements elicited different activity in left and right motoric areas. This lateralization effect was found in two distinct spatio-temporal-spectral clusters: An early lateralization effect in medial sensors at 12–16 Hz and ~276–675 ms after stimulus onset, and a second cluster in more lateral sensors at 22–28 Hz and ~1275–1775 ms. Our results demonstrate that in addition to the known somatotopic organization of parts of the human motoric system, these areas also show a lateralization effect during action observation. Thus, our results indicate that the hemispheric organization of one's own body map known for motion execution extends to the visual observation of others' bodily actions and movements.

Highlights

The recognition of human movements is an important aspect of social interaction
In right sensors, point-light display (PLD) facing to the left elicited stronger power in the beta-band compared to PLD facing to the right and in left sensors, PLD facing to the right elicited stronger power in the beta-band compared to PLD facing to the left (Figure 3A)
Suppression of neuronal activity, especially in the alpha- and beta-band, in motoric systems during action observation has been interpreted as an involvement of the respective areas in the process of action observation (e.g., Babiloni et al, 2002; Pineda, 2008; Kilner et al, 2009; Frenkel-Toledo et al, 2013)

Summary

Introduction

The recognition of human movements is an important aspect of social interaction. Observing other individuals provides rich information about their actions, intentions, moods, etc. (see Blake and Shiffrar, 2007 for an overview). Imaging studies have revealed a widespread cortical network involved in the perception of human movements This network includes visual areas, and higher level cortical areas extending beyond the classical low level visual areas (e.g., Grossman et al, 2000; Saygin et al, 2004; Gilaie-Dotan et al, 2013; Pavlidou et al, 2014b,c). Among these areas is a network known as the mirror neuron system (MNS). The MNS has been first observed in monkeys and is known as a system of neurons which are activated during action execution and during observation of the

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