title: Real-time EEG feedback during simultaneous EEG-fMRI identifies the cortical signature of motor imagery.
abstract: Motor imagery (MI) combined with real-time electroencephalogram (EEG) feedback is a popular approach for steering brain-computer interfaces (BCI). MI BCI has been considered promising as add-on therapy to support motor recovery after stroke. Yet whether EEG neurofeedback indeed targets specific sensorimotor activation patterns cannot be unambiguously inferred from EEG alone. We combined MI EEG neurofeedback with concurrent and continuous functional magnetic resonance imaging (fMRI) to characterize the relationship between MI EEG neurofeedback and activation in cortical sensorimotor areas. EEG signals were corrected online from interfering MRI gradient and ballistocardiogram artifacts, enabling the delivery of real-time EEG feedback. Significantly enhanced task-specific brain activity during feedback compared to no feedback blocks was present in EEG and fMRI. Moreover, the contralateral MI related decrease in EEG sensorimotor rhythm amplitude correlated inversely with fMRI activation in the contralateral sensorimotor areas, whereas a lateralized fMRI pattern did not necessarily go along with a lateralized EEG pattern. Together, the findings indicate a complex relationship between MI EEG signals and sensorimotor cortical activity, whereby both are similarly modulated by EEG neurofeedback. This finding supports the potential of MI EEG neurofeedback for motor rehabilitation and helps to better understand individual differences in MI BCI performance.
authors.affiliation: Neuropsychology Lab, Department of Psychology, European Medical School, University of Oldenburg, Oldenburg, Germany. Electronic address: catharina.zich@uni-oldenburg.de.
authors.forename: Catharina
authors.initials: C
authors.lastname: Zich
authors.affiliation: Neuropsychology Lab, Department of Psychology, European Medical School, University of Oldenburg, Oldenburg, Germany; Cluster of Excellence Hearing4All, University of Oldenburg, Oldenburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Debener
authors.affiliation: Neuropsychology Lab, Department of Psychology, European Medical School, University of Oldenburg, Oldenburg, Germany.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Kranczioch
authors.affiliation: Neuropsychology Lab, Department of Psychology, European Medical School, University of Oldenburg, Oldenburg, Germany; Cluster of Excellence Hearing4All, University of Oldenburg, Oldenburg, Germany.
authors.forename: Martin G
authors.initials: MG
authors.lastname: Bleichner
authors.affiliation: BlindSight GmbH, Schlitz, Germany.
authors.forename: Ingmar
authors.initials: I
authors.lastname: Gutberlet
authors.affiliation: Cluster of Excellence Hearing4All, University of Oldenburg, Oldenburg, Germany; Methods in Neurocognitive Psychology Lab, Department of Psychology, European Medical School, University of Oldenburg, Oldenburg, Germany; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK.
authors.forename: Maarten
authors.initials: M
authors.lastname: De Vos
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009068:Movement; D058765:Neurofeedback; D066191:Sensorimotor Cortex / Q000502:physiology*; D055815:Young Adult
keywords: BCI illiteracy; Brain–computer interface (BCI); Concurrent EEG–fMRI; Motor imagery