Determining hemispheric language dominance from MEG beta-power modulations: Concordance with fMRI. Neuroimage 2026 Jun 11;338:122051
Date
06/12/2026Pubmed ID
42276436Pubmed Central ID
PMC13373884DOI
10.1016/j.neuroimage.2026.122051Scopus ID
2-s2.0-105041509306 (requires institutional sign-in at Scopus site)Abstract
Accurate identification of the language-dominant hemisphere is essential for surgical planning in drug-resistant focal epilepsy. Functional MRI is widely used as a noninvasive alternative to the Wada test but may be contraindicated or unreliable in some patients, motivating complementary approaches such as magnetoencephalography (MEG). We tested whether beta-band MEG power suppression can provide reliable language lateralization when combined with a task-matched nonlinguistic control, participant/ROI-specific timing, and a multi-threshold weighted-bootstrap laterality index (LI). Seventy-four adults with temporal lobe epilepsy completed visual semantic-decision and false-font control tasks during MEG. Beta-band (17-25 Hz) source power was estimated with DICS beamforming, and LIs were computed in frontal, temporal, angular, and composite lateral ROIs using 300-ms sliding windows. For comparison, participants also completed an auditory semantic-decision versus tone-decision fMRI protocol, with fMRI LIs derived from matched ROIs. MEG showed a left-lateralized spatiotemporal sequence in which frontal LI emerged earlier than temporal-parietal LI, following early bilateral temporo-parieto-occipital engagement. Compared with a prestimulus baseline, the false-font control contrast increased LI magnitude and improved MEG-fMRI correspondence, with a peak MEG-fMRI correlation of r = 0.65. Participant/ROI-specific timing produced only small and mixed changes in concordance. Using the optimized MEG pipeline, MEG and fMRI agreed in 67/74 patients (90.5%; 95% CI: 83-96%; κ = 0.81). Bootstrap LIs performed similarly to magnitude- and vertex-count-based variants while providing confidence intervals. These findings suggest that beta-band MEG suppression during semantic decision, especially when contrasted with a nonlinguistic control task, provides a temporally resolved and clinically feasible marker of hemispheric language dominance that is highly concordant with fMRI.
Author List
Youssofzadeh V, Binder JR, Heffernan J, Bock E, Jaiswal A, Stout J, Ustine C, Chikara RK, Shah-Basak P, Humphries C, Mathis J, Conant LL, Gross WL, Carlson C, Anderson CT, Hermann B, Meyerand B, Raghavan MAuthors
William Gross PhD, MD Associate Professor in the Anesthesiology department at Medical College of WisconsinManoj Raghavan PhD, MD Professor in the Neurology department at Medical College of Wisconsin
Vahab Youssofzadeh PhD Assistant Professor in the Neurology department at Medical College of Wisconsin
