Effects of augmented feedback delay on neural correlates of feedback processing in motor practice

Distinct neural correlates are associated with the processing of augmented feedback during motor learning. To examine the basic neural response of delayed augmented feedback, 33 participants practiced a right-arm flexion-extension-movement performed with an arm-lever-device in 192 trials with subsequent feedback presentation. The movement sequence consisted of three movement reversals, which were practiced with the goal of minimizing errors in spatial accuracy. Based on a performance-adaptive bandwidth for spatial movement accuracy, participants received delayed augmented feedback indicating whether they had achieved one predefined reversal (of the three), or not. The feedback delay duration alternated block-wise between 1500 ms and 7000 ms. EEG was recorded throughout practice. The error-related negativity (ERN) and the error positivity (Pe) are assumed to reflect neural error processing in a predictive manner based on intrinsic information, whereas the feedback-related negativity (FRN) is assumed to reflect neural error processing in a postdictive manner based on extrinsic outcome feedback. It was hypothesized that the ERN and the Pe would be more pronounced in trials with longer feedback delays, which unfortunately could not be tested. The relevant components were not detected in the signal, possibly due to the complex sequential structure of the task and the feedback pattern. With respect to feedback valence, results regarding the FRN were as expected. Further, the results demonstrate a more pronounced neural processing of augmented feedback with respect to a shorter feedback delay duration. These results indicate that delaying augmented feedback impacts the neural processing of augmented feedback in motor practice.