Modulation of motor cortex activity when observing rewarding and punishing actions

Abstract

a b s t r a c tInterpreting others' actions is essential for understanding the intentions and goals in social interactions. Activity in the motor cortex is evoked when we see another person performing actions, which can also be influenced by the intentions and context of the observed action. No study has directly explored the influence of reward and punishment on motor cortex activity when observing others' actions, which is likely to have substantial relevance in different social contexts. In this experiment, EEG was recorded while participants watched movie clips of a person performing actions that led to a monetary reward, loss or no change for the observer. Using the EEG mu rhythm as an index of motor resonance, our results demonstrate that observation of rewarding actions produce significantly greater motor cortex activity than punishing or neutral actions, with punishing actions producing greater activity than neutral ones. In addition, the dynamic change in the mu rhythm over sensorimotor cortex is modulated by reward and punishment, with punishing actions producing a prolonged suppression. These findings demonstrate that the associated reward value of an observed action may be crucial in determining the strength of the representation of the action in the observer's brain. Consequently, reward and punishment is likely to drive observational learning through changes in the action observation network, and may also influence how we interpret, understand, engage in and empathize with others' actions in social interaction.

Reward modulates the mirror neuron system in schizophrenia: A study into the mu rhythm suppression, empathy, and mental state attribution

“…This effect seems to be comparable to the reward-related modulation seen in the earlier study in a healthy population (Brown et al, 2013), whereby rewarding and punishing actions evoked greater mu suppression than neutral, nonrewarding actions. To some degree, this result contrasts with studies looking at reward-related cortical responses with fMRI in which schizophrenia patients were shown to have abnormal responses to monetary gains and losses (Waltz et al, 2010).…”

“…Actions were seen either being performed from a first-person or third-person point of view, which were rewarding, punishing, or neutral (i.e., 2 × 3 design). The task structure is depicted in Figure 1, which follows the same design as in Brown et al (2013).…”

“…If reward does play a role in social interaction and in promoting social goal-seeking and social motivation, then a deficit in reward processing is also likely to have a detrimental impact on social functioning and the acquisition of social skills. A study from our group (Brown, Wiersema, Pourtois, & Brüne, 2013) demonstrated that the mu suppression is modulated by rewards associated with the observed action, whereby greater mu suppression is evoked when observing actions that are financially rewarding for the observer. Thus it follows that if reward plays a role in the magnitude of mu rhythm suppression, then a deficit in reward processing may also have a detrimental impact on motor resonance during action observation, which has not previously been accounted for.…”

Assessing human mirror activity with EEG mu rhythm: A meta-analysis.

“…Few studies have taken advantage of the ability to use EEG to assess the chronometry of mu desynchronization (Avanzini et al, 2012; Brown, Wiersema, Pourtois, & Brüne, 2013; Heimann, Umiltà, & Gallese, 2013; Muthukumaraswamy & Johnson, 2004b; Nyström, 2008; Orgs et al, 2008). There were too few studies to systematically examine timing effects on mu desynchronization in the present meta-analysis.…”

Social Coordination Information in Dynamic Chase Modulates EEG Mu Rhythm

“…Researchers even found that degraded images of action based on point-light biological motion can modulate Mu rhythm 14 . Moreover, a growing body of studies suggested that Mu rhythm is sensitive to various parameters of actions, such as forms, directness, and the values associated with actions 9, 22–24 . For example, a transitive action with a directed goal suppressed the Mu rhythm more strongly than an intransitive action 9, 23 .…”