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Relationship between activity in human primary motor cortex during action observation and the mirror neuron system.

Kilner JM, Marchant JL, Frith CD - PLoS ONE (2009)

Bottom Line: We asked subjects to observe videos of an actor making a variety of arm movements.This pattern of attenuation was driven by the side of the screen on which the observed movement occurred and not by the hand that was observed moving.These results are discussed in terms of the firing patterns of mirror neurons in F5 which have been reported to have similar properties.

View Article: PubMed Central - PubMed

Affiliation: The Wellcome Trust Centre for Neuroimaging, London, London, United Kingdom. j.kilner@fil.ion.ucl.ac.uk

ABSTRACT
The attenuation of the beta cortical oscillations during action observation has been interpreted as evidence of a mirror neuron system (MNS) in humans. Here we investigated the modulation of beta cortical oscillations with the viewpoint of an observed action. We asked subjects to observe videos of an actor making a variety of arm movements. We show that when subjects were observing arm movements there was a significant modulation of beta oscillations overlying left and right sensorimotor cortices. This pattern of attenuation was driven by the side of the screen on which the observed movement occurred and not by the hand that was observed moving. These results are discussed in terms of the firing patterns of mirror neurons in F5 which have been reported to have similar properties.

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Sensor space statistical parametric maps.Figure 2a shows the statistical parametric map where beta power was smaller when observing a right handed action then when observing a left handed action in sensor space. Figure 2b shows the statistical parametric map for the interaction between the hand observed and the direction the actor's head was facing. The colour-scale in both (a) and (b) depicts the t-value. These statistical maps were thresholded at p<0.005 (uncorrected). Figure 2c shows the time course of the betas (a.u.) averaged across voxels that were above the p<0.005 threshold that are shown in panels (a) and (b). The blue line shows the time course for the beta value for the contrast shown in panel a The red line shows the time course for the beta value for the contrast shown in panel b. The grey box shows the period of action observation. TR – towards right hand, TL – towards left hand, AR – away right hand, AL – away left hand. It should be noted that the reciprocal nature of the modulations in the left and right hemisphere can not simply reflect extrema of classic dipolar field patterns as here we consider sensor space maps of power where the data has been squared and, therefore, is always positive.
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pone-0004925-g002: Sensor space statistical parametric maps.Figure 2a shows the statistical parametric map where beta power was smaller when observing a right handed action then when observing a left handed action in sensor space. Figure 2b shows the statistical parametric map for the interaction between the hand observed and the direction the actor's head was facing. The colour-scale in both (a) and (b) depicts the t-value. These statistical maps were thresholded at p<0.005 (uncorrected). Figure 2c shows the time course of the betas (a.u.) averaged across voxels that were above the p<0.005 threshold that are shown in panels (a) and (b). The blue line shows the time course for the beta value for the contrast shown in panel a The red line shows the time course for the beta value for the contrast shown in panel b. The grey box shows the period of action observation. TR – towards right hand, TL – towards left hand, AR – away right hand, AL – away left hand. It should be noted that the reciprocal nature of the modulations in the left and right hemisphere can not simply reflect extrema of classic dipolar field patterns as here we consider sensor space maps of power where the data has been squared and, therefore, is always positive.

Mentions: Analysis of the 2×2 factorial design shown in Fig. 1A revealed two contrasts that showed significant modulations in beta power during the period of action observation. Firstly there was a main effect of the hand observed (Fig. 2A). Beta power was significantly more attenuated (peak voxel t = 6.21, p<0.05 corrected for multiple comparisons) at sensors overlying the right sensorimotor cortex when the subjects observed movements of the right hand compared to the left hand. This effect was observed throughout the 2 s period of action observation (blue line Figure 2C) and peaked at 1670 ms, 670 ms after movement onset. No voxels were significant for the reverse contrast (p>0.005). In other words there were no voxels where beta power was more attenuated when observing all movements of the left hand compared to the right hand. However, there was a significant interaction between the hand observed and the direction the actors' head was facing (Fig. 2B). This modest yet significant modulation of beta power (peak voxel t = 2.80, p<0.005 uncorrected) was observed at sensors overlying the left sensorimotor cortex and peaked at 2330 ms, 1330 ms after movement onset (red line Fig. 2C).


Relationship between activity in human primary motor cortex during action observation and the mirror neuron system.

Kilner JM, Marchant JL, Frith CD - PLoS ONE (2009)

Sensor space statistical parametric maps.Figure 2a shows the statistical parametric map where beta power was smaller when observing a right handed action then when observing a left handed action in sensor space. Figure 2b shows the statistical parametric map for the interaction between the hand observed and the direction the actor's head was facing. The colour-scale in both (a) and (b) depicts the t-value. These statistical maps were thresholded at p<0.005 (uncorrected). Figure 2c shows the time course of the betas (a.u.) averaged across voxels that were above the p<0.005 threshold that are shown in panels (a) and (b). The blue line shows the time course for the beta value for the contrast shown in panel a The red line shows the time course for the beta value for the contrast shown in panel b. The grey box shows the period of action observation. TR – towards right hand, TL – towards left hand, AR – away right hand, AL – away left hand. It should be noted that the reciprocal nature of the modulations in the left and right hemisphere can not simply reflect extrema of classic dipolar field patterns as here we consider sensor space maps of power where the data has been squared and, therefore, is always positive.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2654140&req=5

pone-0004925-g002: Sensor space statistical parametric maps.Figure 2a shows the statistical parametric map where beta power was smaller when observing a right handed action then when observing a left handed action in sensor space. Figure 2b shows the statistical parametric map for the interaction between the hand observed and the direction the actor's head was facing. The colour-scale in both (a) and (b) depicts the t-value. These statistical maps were thresholded at p<0.005 (uncorrected). Figure 2c shows the time course of the betas (a.u.) averaged across voxels that were above the p<0.005 threshold that are shown in panels (a) and (b). The blue line shows the time course for the beta value for the contrast shown in panel a The red line shows the time course for the beta value for the contrast shown in panel b. The grey box shows the period of action observation. TR – towards right hand, TL – towards left hand, AR – away right hand, AL – away left hand. It should be noted that the reciprocal nature of the modulations in the left and right hemisphere can not simply reflect extrema of classic dipolar field patterns as here we consider sensor space maps of power where the data has been squared and, therefore, is always positive.
Mentions: Analysis of the 2×2 factorial design shown in Fig. 1A revealed two contrasts that showed significant modulations in beta power during the period of action observation. Firstly there was a main effect of the hand observed (Fig. 2A). Beta power was significantly more attenuated (peak voxel t = 6.21, p<0.05 corrected for multiple comparisons) at sensors overlying the right sensorimotor cortex when the subjects observed movements of the right hand compared to the left hand. This effect was observed throughout the 2 s period of action observation (blue line Figure 2C) and peaked at 1670 ms, 670 ms after movement onset. No voxels were significant for the reverse contrast (p>0.005). In other words there were no voxels where beta power was more attenuated when observing all movements of the left hand compared to the right hand. However, there was a significant interaction between the hand observed and the direction the actors' head was facing (Fig. 2B). This modest yet significant modulation of beta power (peak voxel t = 2.80, p<0.005 uncorrected) was observed at sensors overlying the left sensorimotor cortex and peaked at 2330 ms, 1330 ms after movement onset (red line Fig. 2C).

Bottom Line: We asked subjects to observe videos of an actor making a variety of arm movements.This pattern of attenuation was driven by the side of the screen on which the observed movement occurred and not by the hand that was observed moving.These results are discussed in terms of the firing patterns of mirror neurons in F5 which have been reported to have similar properties.

View Article: PubMed Central - PubMed

Affiliation: The Wellcome Trust Centre for Neuroimaging, London, London, United Kingdom. j.kilner@fil.ion.ucl.ac.uk

ABSTRACT
The attenuation of the beta cortical oscillations during action observation has been interpreted as evidence of a mirror neuron system (MNS) in humans. Here we investigated the modulation of beta cortical oscillations with the viewpoint of an observed action. We asked subjects to observe videos of an actor making a variety of arm movements. We show that when subjects were observing arm movements there was a significant modulation of beta oscillations overlying left and right sensorimotor cortices. This pattern of attenuation was driven by the side of the screen on which the observed movement occurred and not by the hand that was observed moving. These results are discussed in terms of the firing patterns of mirror neurons in F5 which have been reported to have similar properties.

Show MeSH
Related in: MedlinePlus