Activity in primary motor cortex during action observation covaries with subsequent behavioral changes in execution

• Published in: Brain and behavior Vol. 6; no. 11; pp. e00550 - n/a
• Main Authors: Aridan, Nadav, Mukamel, Roy
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.11.2016; John Wiley and Sons Inc
• Subjects: Adolescent; Adult; Behavior; Behavior - physiology; Executive Function - physiology; Female; functional magnetic resonance imaging; Grants; Humans; imitation; Learning - physiology; Magnetic Resonance Imaging - methods; Male; Memory - physiology; mirror neurons; Motor Cortex - diagnostic imaging; Motor Cortex - physiology; motor system; Original Research; Psychomotor Performance - physiology; Science; Studies; Young Adult; Israel; motor system; imitation; mirror neurons; functional magnetic resonance imaging
• ISSN: 2162-3279; 2162-3279
• DOI: 10.1002/brb3.550

Introduction Observing someone else perform a movement facilitates motor planning, execution, and motor memory formation. Rate, an important feature in the execution of repeated movements, has been shown to vary following movement observation although the underlying neural mechanisms are unclear. In the current study, we examined how the rate of self‐paced index finger pressing is implicitly modified following passive observation of a similar action performed at a different rate. Methods Fifty subjects performed a finger pressing sequence with their right hand at their own pace before and after passive observation of either a 1‐min video depicting the task performed at 3 Hz by someone else or a black screen. An additional set of 15 subjects performed the task in an MRI scanner. Results Across all 50 subjects, the spontaneous execution rate prior to video observation had a bimodal distribution with modes around 2 and 4 Hz. Following video observation, the slower subjects performed the task at an increased rate. In the 15 subjects who performed the task in the MRI scanner, we found positive correlation between fMRI signal in the left primary motor strip during passive video observation and subsequent behavioral changes in task performance rate. Conclusion We conclude that observing someone else perform an action at a higher rate implicitly increases the spontaneous rate of execution, and that this implicit induction is mediated by activity in the contralateral primary motor cortex. We demonstrate that following exposure to a video depicting someone else perform a button‐pressing task, subjects tend to implicitly shift their spontaneous execution rate toward the rate of the observed action but only if it is higher. The degree of this behavioral shift correlates with the degree of activation elicited during action observation in the relevant motor cortex.