title: Movement-related beta oscillations show high intra-individual reliability.
abstract: Oscillatory activity in the beta frequency range (15-30Hz) recorded from human sensorimotor cortex is of increasing interest as a putative biomarker of motor system function and dysfunction. Despite its increasing use in basic and clinical research, surprisingly little is known about the test-retest reliability of spectral power and peak frequency measures of beta oscillatory signals from sensorimotor cortex. Establishing that these beta measures are stable over time in healthy populations is a necessary precursor to their use in the clinic. Here, we used scalp electroencephalography (EEG) to evaluate intra-individual reliability of beta-band oscillations over six sessions, focusing on changes in beta activity during movement (Movement-Related Beta Desynchronization, MRBD) and after movement termination (Post-Movement Beta Rebound, PMBR). Subjects performed visually-cued unimanual wrist flexion and extension. We assessed Intraclass Correlation Coefficients (ICC) and between-session correlations for spectral power and peak frequency measures of movement-related and resting beta activity. Movement-related and resting beta power from both sensorimotor cortices was highly reliable across sessions. Resting beta power yielded highest reliability (average ICC=0.903), followed by MRBD (average ICC=0.886) and PMBR (average ICC=0.663). Notably, peak frequency measures yielded lower ICC values compared to the assessment of spectral power, particularly for movement-related beta activity (ICC=0.386-0.402). Our data highlight that power measures of movement-related beta oscillations are highly reliable, while corresponding peak frequency measures show greater intra-individual variability across sessions. Importantly, our finding that beta power estimates show high intra-individual reliability over time serves to validate the notion that these measures reflect meaningful individual differences that can be utilised in basic research and clinical studies.
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, 33 Queen Square, WC1N 3BG London, UK. Electronic address: Svenja.Espenhahn.13@ucl.ac.uk.
authors.forename: Svenja
authors.initials: S
authors.lastname: Espenhahn
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, 33 Queen Square, WC1N 3BG London, UK; Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, WC1N 3BG London, UK.
authors.forename: Archy O
authors.initials: AO
authors.lastname: de Berker
authors.affiliation: Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, WC1N 3BG London, UK; Department of Neurology, Charité University Medicine, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Bernadette C M
authors.initials: BCM
authors.lastname: van Wijk
authors.affiliation: Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Maindy Road, CF24 4HQ Cardiff, UK.
authors.forename: Holly E
authors.initials: HE
authors.lastname: Rossiter
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, 33 Queen Square, WC1N 3BG London, UK.
authors.forename: Nick S
authors.initials: NS
authors.lastname: Ward
mesh_terms: D000328:Adult; D001611:Beta Rhythm / Q000502:physiology*; D001696:Biomechanical Phenomena; D003463:Cues; D004569:Electroencephalography; D058407:Electroencephalography Phase Synchronization; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D015203:Reproducibility of Results; D013003:Somatosensory Cortex / Q000502:physiology*; D014953:Wrist / Q000294:innervation / Q000502:physiology; D055815:Young Adult
keywords: Beta oscillations; EEG; Intraclass correlation coefficient; Sensorimotor cortex; Test-retest reliability