Characterising motor and cognitive contributions of cortical beta oscillations and their modulation with rTMS.
Level 3 - non-randomized controlled study
Controlled within-subject experimental laboratory study in healthy humans
PubMed 41903596 · doi:10.1016/j.neuroimage.2026.121893
What was done
Twenty-four healthy participants completed a visually cued reaching task under dynamically manipulated uncertainty while electroencephalography (EEG) recorded cortical beta-band oscillations. Reaction time was measured across three repetitive transcranial magnetic stimulation (rTMS) conditions delivered during the preparatory interval: no stimulation, regular rTMS tuned to each individual's beta frequency, and irregular rTMS.
What was found
The abstract reports directional findings without numerical values, confidence intervals, or exact p-values: - Uncertainty cues produced bilateral beta suppression, with greater uncertainty associated with smaller reductions in beta power. - Movement preparation was lateralised contralateral to the executing hand, where higher pre-go beta power correlated with longer reaction times. - Both regular and irregular rTMS significantly shortened reaction times and attenuated beta event-related desynchronisation. - Regular rTMS timed to the beta down state had a significantly stronger effect. - Reductions in beta desynchronisation correlated with reaction time improvements.
Why it matters
This work demonstrates that cortical beta rhythms separate bilateral cognitive uncertainty from lateralised motor preparation, and shows that phase-locked beta rTMS can lower the neural threshold for movement initiation.
Limits
The sample is small (n = 24) and limited to healthy volunteers performing an acute laboratory task. The abstract provides no quantitative metrics, effect sizes, or variance measures, and no clinical or long-term outcomes were assessed.