Integration of action value during action observation

Transcranial magnetic stimulation (TMS) studies consistently demonstrated that observing the actions of other individuals leads to a muscle-specific increase in primary motor cortex (M1) excitability (i.e., motor resonance). Although it has been shown that motor resonance is modulated by contextual information accompanying others actions, it is currently unknown whether action value is integrated into behavioral and physiological outcomes during action observation. Here, we tested whether response times (RT; experiment 1) and muscle-specific motor resonance (experiment 2) are modulated by the value associated with an observed action. Our results show that observing highly-valued actions leads to a decrease in RT variability, as well as a strengthening of muscle-specific motor resonance. This sharpening of behavioural and neural responses was contrasted to a matched control task that manipulated attention independent of the reward value. Collectively, our findings suggest that action value is integrated during action observation and is able to enhance both the precision of behavioral responses, as well as the neural tuning of M1 action representations.