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Attention modulates motor system activation during action observation: evidence for inhibitory rebound.

Schuch S, Bayliss AP, Klein C, Tipper SP - Exp Brain Res (2010)

Bottom Line: We investigated whether this effect is stronger when the observed action is relevant to the observer's task.Results show mu rhythm attenuation when watching the videos relative to baseline.This enhancement was again stronger when making judgments about the grasp than the colour, suggesting that the stronger activation is followed by a stronger inhibitory rebound.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, Bangor University, Bangor, UK. schuch@psych.rwth-aachen.de

ABSTRACT
Perceiving another individual's actions activates the human motor system. We investigated whether this effect is stronger when the observed action is relevant to the observer's task. The mu rhythm (oscillatory activity in the 8- to 13-Hz band over sensorimotor cortex) was measured while participants watched videos of grasping movements. In one of two conditions, the participants had to later report how many times they had seen a certain kind of grasp. In the other condition, they viewed the identical videos but had to later report how many times they had seen a certain colour change. The colour change and the grasp always occurred simultaneously. Results show mu rhythm attenuation when watching the videos relative to baseline. This attenuation was stronger when participants later reported the grasp rather than the colour, suggesting that the motor system is more strongly activated when the observed grasping actions were relevant to the observer's task. Moreover, when the graspable object disappeared after the offset of the video, there was subsequent mu rhythm enhancement, reflecting a post-stimulus inhibitory rebound. This enhancement was again stronger when making judgments about the grasp than the colour, suggesting that the stronger activation is followed by a stronger inhibitory rebound.

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Topographical map showing the t values of the difference in 8- to 13-Hz power between report-colour task and report-grasp task during Interval 8 (observation of grasp) for the combined data of stimulus offset/maintenance condition (df = 26). Negative t values indicate less mu power for the report-grasp task than report-colour task
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Fig5: Topographical map showing the t values of the difference in 8- to 13-Hz power between report-colour task and report-grasp task during Interval 8 (observation of grasp) for the combined data of stimulus offset/maintenance condition (df = 26). Negative t values indicate less mu power for the report-grasp task than report-colour task

Mentions: To check for potential differences between the two tasks at other electrode sites, the t values of the difference between the two observation conditions were computed and plotted in topographical maps. Two critical time windows were chosen for this analysis: the observation of grasp (interval 8) and the post observation period (interval 12). Negative t values indicate less mu power in report-grasp than report-colour task, positive t values indicate more mu power in report-grasp than report-colour. Figure 5 shows that during the observation of the grasp, the difference between the two tasks was most pronounced over left central channels, confirming that the difference is largest over motor areas. That the difference is left-lateralised is presumably due to the stimulus material being lateralised, with a right hand appearing from the right of the screen to grasp the cup, and the cup handle pointing to the right).Fig. 5


Attention modulates motor system activation during action observation: evidence for inhibitory rebound.

Schuch S, Bayliss AP, Klein C, Tipper SP - Exp Brain Res (2010)

Topographical map showing the t values of the difference in 8- to 13-Hz power between report-colour task and report-grasp task during Interval 8 (observation of grasp) for the combined data of stimulus offset/maintenance condition (df = 26). Negative t values indicate less mu power for the report-grasp task than report-colour task
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2914260&req=5

Fig5: Topographical map showing the t values of the difference in 8- to 13-Hz power between report-colour task and report-grasp task during Interval 8 (observation of grasp) for the combined data of stimulus offset/maintenance condition (df = 26). Negative t values indicate less mu power for the report-grasp task than report-colour task
Mentions: To check for potential differences between the two tasks at other electrode sites, the t values of the difference between the two observation conditions were computed and plotted in topographical maps. Two critical time windows were chosen for this analysis: the observation of grasp (interval 8) and the post observation period (interval 12). Negative t values indicate less mu power in report-grasp than report-colour task, positive t values indicate more mu power in report-grasp than report-colour. Figure 5 shows that during the observation of the grasp, the difference between the two tasks was most pronounced over left central channels, confirming that the difference is largest over motor areas. That the difference is left-lateralised is presumably due to the stimulus material being lateralised, with a right hand appearing from the right of the screen to grasp the cup, and the cup handle pointing to the right).Fig. 5

Bottom Line: We investigated whether this effect is stronger when the observed action is relevant to the observer's task.Results show mu rhythm attenuation when watching the videos relative to baseline.This enhancement was again stronger when making judgments about the grasp than the colour, suggesting that the stronger activation is followed by a stronger inhibitory rebound.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, Bangor University, Bangor, UK. schuch@psych.rwth-aachen.de

ABSTRACT
Perceiving another individual's actions activates the human motor system. We investigated whether this effect is stronger when the observed action is relevant to the observer's task. The mu rhythm (oscillatory activity in the 8- to 13-Hz band over sensorimotor cortex) was measured while participants watched videos of grasping movements. In one of two conditions, the participants had to later report how many times they had seen a certain kind of grasp. In the other condition, they viewed the identical videos but had to later report how many times they had seen a certain colour change. The colour change and the grasp always occurred simultaneously. Results show mu rhythm attenuation when watching the videos relative to baseline. This attenuation was stronger when participants later reported the grasp rather than the colour, suggesting that the motor system is more strongly activated when the observed grasping actions were relevant to the observer's task. Moreover, when the graspable object disappeared after the offset of the video, there was subsequent mu rhythm enhancement, reflecting a post-stimulus inhibitory rebound. This enhancement was again stronger when making judgments about the grasp than the colour, suggesting that the stronger activation is followed by a stronger inhibitory rebound.

Show MeSH