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

• Published in: Experimental brain research 2010-08, Vol.205 (2), p.235-249
• Main Authors: Schuch, Stefanie, Bayliss, Andrew P, Klein, Christoph, Tipper, Steven P
• Format: Article
• Language: English
• Subjects: Action perception; Adult and adolescent clinical studies; Attention; Attention - physiology; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Data Interpretation, Statistical; EEG; Efferent Pathways - physiology; Electrodes; Electroencephalography; Eye Movements; Female; Fundamental and applied biological sciences. Psychology; Hand Strength - physiology; Humans; Inhibition; Language and communication disorders; Medical sciences; Mirror system; Mirrors; Motion Perception - physiology; Motor ability; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Mu rhythm; Neurology; Neurosciences; Photic Stimulation; Psychological research; Psychology. Psychoanalysis. Psychiatry; Psychomotor Performance - physiology; Psychopathology. Psychiatry; Research Article; Vertebrates: nervous system and sense organs; Vision; Young Adult
• ISSN: 0014-4819; 1432-1106; 1432-1106
• DOI: 10.1007/s00221-010-2358-4

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.