Reward and punishment: the neural correlates of reinforcement feedback during motor learning

‘By the carrot or the stick’ reward or punishment has been contemplated by instructors to motivate their pupils to learn a new motor skill. The reinforcements of reward and punishment have demonstrated dissociable effects on motor learning with punishment enhancing the learning rate and reward increasing retention of the motor task. However it is still unclear how the brain processes reward and punishment during motor learning. This study sought to investigate the role of reinforcement feedback in cortical neural activity associated with motor learning. A novel visuomotor rotation task was employed with reward punishment or null feedback as the participants adapted their movement to a 30-degree counter-clockwise rotation. We measured movement time and task accuracy throughout the task. Surface electroencephalography was utilized to record cortical neural activity throughout the learning and retention of the motor task. Event-related potentials (ERPs) were calculated to assess how the brain processes the reinforcement feedback and prepares for movement. Repeated measures ANOVAs were utilized to detect differences in the movement parameters and ERP amplitudes. This study found that reward and punishment feedback did not produce different effects on the rate of task learning. However punishment feedback impaired the retention (memory) of the motor task. These behavioral effects were accompanied by changes in the amplitude of ERPs during feedback presentation and movement preparation. These results suggest that punishment feedback alters brain processes involved in memory formation during motor learning