title: Proprioceptive Feedback Facilitates Motor Imagery-Related Operant Learning of Sensorimotor β-Band Modulation.
abstract: Motor imagery (MI) activates the sensorimotor system independent of actual movements and might be facilitated by neurofeedback. Knowledge on the interaction between feedback modality and the involved frequency bands during MI-related brain self-regulation is still scarce. Previous studies compared the cortical activity during the MI task with concurrent feedback (MIwithfeedback condition) to cortical activity during the relaxation task where no feedback was provided (relaxationwithoutfeedback condition). The observed differences might, therefore, be related to either the task or the feedback. A proper comparison would necessitate studying a relaxation condition with feedback and a MI task condition without feedback as well. Right-handed healthy subjects performed two tasks, i.e., MI and relaxation, in alternating order. Each of the tasks (MI vs. relaxation) was studied with and without feedback. The respective event-driven oscillatory activity, i.e., sensorimotor desynchronization (during MI) or synchronization (during relaxation), was rewarded with contingent feedback. Importantly, feedback onset was delayed to study the task-related cortical activity in the absence of feedback provision during the delay period. The reward modality was alternated every 15 trials between proprioceptive and visual feedback. Proprioceptive input was superior to visual input to increase the range of task-related spectral perturbations in the α- and β-band, and was necessary to consistently achieve MI-related sensorimotor desynchronization (ERD) significantly below baseline. These effects occurred in task periods without feedback as well. The increased accuracy and duration of learned brain self-regulation achieved in the proprioceptive condition was specific to the β-band. MI-related operant learning of brain self-regulation is facilitated by proprioceptive feedback and mediated in the sensorimotor β-band.
authors.affiliation: School of Electrical and Electronic Engineering, University of AdelaideAdelaide, SA, Australia; Division of Functional and Restorative Neurosurgery, and Centre for Integrative Neuroscience, Eberhard Karls University TuebingenTubingen, Germany.
authors.forename: Sam
authors.initials: S
authors.lastname: Darvishi
authors.affiliation: Division of Functional and Restorative Neurosurgery, and Centre for Integrative Neuroscience, Eberhard Karls University Tuebingen Tubingen, Germany.
authors.forename: Alireza
authors.initials: A
authors.lastname: Gharabaghi
authors.affiliation: The Ottawa Hospital Research Institute, University of Ottawa Ottawa, ON, Canada.
authors.forename: Chadwick B
authors.initials: CB
authors.lastname: Boulay
authors.affiliation: The Robinson Research Institute, University of Adelaide Adelaide, SA, Australia.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Ridding
authors.affiliation: School of Electrical and Electronic Engineering, University of Adelaide Adelaide, SA, Australia.
authors.forename: Derek
authors.initials: D
authors.lastname: Abbott
authors.affiliation: School of Electrical and Electronic Engineering, University of Adelaide Adelaide, SA, Australia.
authors.forename: Mathias
authors.initials: M
authors.lastname: Baumert
keywords: beta rhythms; brain-computer interface; brain-machine interface; brain-robot interface; neurorehabilitation; operant conditioning; reinforcement learning; stroke