title: Test-retest reliability of resting-state magnetoencephalography power in sensor and source space.
abstract: Several studies have reported changes in spontaneous brain rhythms that could be used as clinical biomarkers or in the evaluation of neuropsychological and drug treatments in longitudinal studies using magnetoencephalography (MEG). There is an increasing necessity to use these measures in early diagnosis and pathology progression; however, there is a lack of studies addressing how reliable they are. Here, we provide the first test-retest reliability estimate of MEG power in resting-state at sensor and source space. In this study, we recorded 3 sessions of resting-state MEG activity from 24 healthy subjects with an interval of a week between each session. Power values were estimated at sensor and source space with beamforming for classical frequency bands: delta (2-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), low beta (13-20 Hz), high beta (20-30 Hz), and gamma (30-45 Hz). Then, test-retest reliability was evaluated using the intraclass correlation coefficient (ICC). We also evaluated the relation between source power and the within-subject variability. In general, ICC of theta, alpha, and low beta power was fairly high (ICC > 0.6) while in delta and gamma power was lower. In source space, fronto-posterior alpha, frontal beta, and medial temporal theta showed the most reliable profiles. Signal-to-noise ratio could be partially responsible for reliability as low signal intensity resulted in high within-subject variability, but also the inherent nature of some brain rhythms in resting-state might be driving these reliability patterns. In conclusion, our results described the reliability of MEG power estimates in each frequency band, which could be considered in disease characterization or clinical trials.
authors.affiliation: Laboratory of Cognitive and Computational Neuroscience, Centre for Biomedical Technology, Madrid, Spain.|Psychology Division, Cardenal Cisneros University College, Complutense University of Madrid, Spain.|Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain.
authors.forename: María Carmen
authors.initials: MC
authors.lastname: Martín-Buro
authors.affiliation: Laboratory of Cognitive and Computational Neuroscience, Centre for Biomedical Technology, Madrid, Spain.|Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain.|Department of Applied Physics III, Faculty of Physics, Complutense University of Madrid, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Garcés
authors.affiliation: Laboratory of Cognitive and Computational Neuroscience, Centre for Biomedical Technology, Madrid, Spain.|Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain.|Department of Basic Psychology II, Faculty of Psychology, Complutense University of Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Maestú
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D004569:Electroencephalography; D005123:Eye / Q000294:innervation; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D015203:Reproducibility of Results; D012146:Rest / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D055815:Young Adult
keywords: MEG; brain rhythms; intraclass correlation coefficient; reliability; resting state; signal to noise ratio; spectral power; test-retest