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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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Related in: MedlinePlus

Responses at the peak voxel.Figure 3 shows the average beta power, represented as a percentage change from baseline, which was defined as the 1 s before video onset, from the taken from the peak voxels in Figures 2a and b. White boxes show averages when watching a right hand and black boxes show the averages when subjects were watching a left hand. The different conditions are depicted by the stills from the movies. Significant differences are shown with a * p<0.05. TR – towards right hand, TL – towards left hand, AR – away right hand, AL – away left hand.
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pone-0004925-g003: Responses at the peak voxel.Figure 3 shows the average beta power, represented as a percentage change from baseline, which was defined as the 1 s before video onset, from the taken from the peak voxels in Figures 2a and b. White boxes show averages when watching a right hand and black boxes show the averages when subjects were watching a left hand. The different conditions are depicted by the stills from the movies. Significant differences are shown with a * p<0.05. TR – towards right hand, TL – towards left hand, AR – away right hand, AL – away left hand.

Mentions: Subsequent analyses of these effects focussed on the modulations of beta power at the peak voxel indentified from the two significant SPMs described above. These results are shown in Figure 3. The analysis of these data was in the form of a repeated measures 2×2×2 ANOVA where the factors were hemisphere (Right or Left), the direction the actors' head was facing (towards or away) and the observed hand that was moving (Left or Right). The results of this repeated measures 2×2×2 ANOVA revealed a main effect of hemisphere (F(1,12) = 12.7, p<0.05), a main effect of direction of the actors' head (F(1,12) = 6.0, p<0.05), a main effect of the hand observed moving (F(1,12) = 15.3, p<0.05), and a significant interaction between hemisphere and the hand observed moving (F(1,12) = 17.7, P<0.05). Post-hoc t-test revealed that for data recorded over the right hemisphere beta power was significantly more attenuated (p<0.05) when subjects observed a right hand than when they observed a left hand irrespective of the direction of head gaze (Fig. 3). Whereas for data recorded over the left hemisphere the converse was true. For the left hemisphere beta power was significantly more attenuated (p<0.05) when subjects observed a left hand compared to when they observed a right hand. However, this was only the case when the actor was facing forward; when the actor was facing away there was no significant modulation in the degree of beta power attenuation (p>0.3). It is important to note that one would expect an interaction between the hemisphere and the hand to be significant as the voxels of interest were selected based upon these contrasts. The purpose of reporting it here is to show that the same result is produced when using pooled or partition variance estimates. However, all other significant effects would not necessarily be predicted as they are orthogonal contrasts.


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)

Responses at the peak voxel.Figure 3 shows the average beta power, represented as a percentage change from baseline, which was defined as the 1 s before video onset, from the taken from the peak voxels in Figures 2a and b. White boxes show averages when watching a right hand and black boxes show the averages when subjects were watching a left hand. The different conditions are depicted by the stills from the movies. Significant differences are shown with a * p<0.05. TR – towards right hand, TL – towards left hand, AR – away right hand, AL – away left hand.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0004925-g003: Responses at the peak voxel.Figure 3 shows the average beta power, represented as a percentage change from baseline, which was defined as the 1 s before video onset, from the taken from the peak voxels in Figures 2a and b. White boxes show averages when watching a right hand and black boxes show the averages when subjects were watching a left hand. The different conditions are depicted by the stills from the movies. Significant differences are shown with a * p<0.05. TR – towards right hand, TL – towards left hand, AR – away right hand, AL – away left hand.
Mentions: Subsequent analyses of these effects focussed on the modulations of beta power at the peak voxel indentified from the two significant SPMs described above. These results are shown in Figure 3. The analysis of these data was in the form of a repeated measures 2×2×2 ANOVA where the factors were hemisphere (Right or Left), the direction the actors' head was facing (towards or away) and the observed hand that was moving (Left or Right). The results of this repeated measures 2×2×2 ANOVA revealed a main effect of hemisphere (F(1,12) = 12.7, p<0.05), a main effect of direction of the actors' head (F(1,12) = 6.0, p<0.05), a main effect of the hand observed moving (F(1,12) = 15.3, p<0.05), and a significant interaction between hemisphere and the hand observed moving (F(1,12) = 17.7, P<0.05). Post-hoc t-test revealed that for data recorded over the right hemisphere beta power was significantly more attenuated (p<0.05) when subjects observed a right hand than when they observed a left hand irrespective of the direction of head gaze (Fig. 3). Whereas for data recorded over the left hemisphere the converse was true. For the left hemisphere beta power was significantly more attenuated (p<0.05) when subjects observed a left hand compared to when they observed a right hand. However, this was only the case when the actor was facing forward; when the actor was facing away there was no significant modulation in the degree of beta power attenuation (p>0.3). It is important to note that one would expect an interaction between the hemisphere and the hand to be significant as the voxels of interest were selected based upon these contrasts. The purpose of reporting it here is to show that the same result is produced when using pooled or partition variance estimates. However, all other significant effects would not necessarily be predicted as they are orthogonal contrasts.

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