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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 maps showing the t values of the difference in 8-to 13-Hz power between report-colour task and report-grasp task during Interval 12 (post observation of grasp), separately for stimulus-offset condition (df = 12), and stimulus-maintenance condition (df = 13). Positive t values indicate more mu power for the report-grasp task than report-colour task
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Fig6: Topographical maps showing the t values of the difference in 8-to 13-Hz power between report-colour task and report-grasp task during Interval 12 (post observation of grasp), separately for stimulus-offset condition (df = 12), and stimulus-maintenance condition (df = 13). Positive t values indicate more mu power for the report-grasp task than report-colour task

Mentions: The second critical time window is the post-grasp period (interval 12). As Fig. 6 shows, in the stimulus-offset condition the difference between the tasks is again most pronounced over central sites, confirming that the inhibitory rebound is a motor phenomenon. The rebound is observed over both left and right central channels. In the stimulus-maintenance condition, the cup remains on the screen during interval 12, and no rebound occurs. As can be seen from Fig. 6, there is no significant difference between the two tasks at any electrode sites in this condition.Fig. 6


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 maps showing the t values of the difference in 8-to 13-Hz power between report-colour task and report-grasp task during Interval 12 (post observation of grasp), separately for stimulus-offset condition (df = 12), and stimulus-maintenance condition (df = 13). Positive t values indicate more 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

Fig6: Topographical maps showing the t values of the difference in 8-to 13-Hz power between report-colour task and report-grasp task during Interval 12 (post observation of grasp), separately for stimulus-offset condition (df = 12), and stimulus-maintenance condition (df = 13). Positive t values indicate more mu power for the report-grasp task than report-colour task
Mentions: The second critical time window is the post-grasp period (interval 12). As Fig. 6 shows, in the stimulus-offset condition the difference between the tasks is again most pronounced over central sites, confirming that the inhibitory rebound is a motor phenomenon. The rebound is observed over both left and right central channels. In the stimulus-maintenance condition, the cup remains on the screen during interval 12, and no rebound occurs. As can be seen from Fig. 6, there is no significant difference between the two tasks at any electrode sites in this condition.Fig. 6

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