Sources of the N15 TMS-evoked potential following motor cortex stimulation localize rostrals to TMS-induced electric fields and depend on dose.
Published September 10, 2026. Comparing brain responses with modeled stimulation fields helped clarify what TMS-EEG measures. An early EEG response did not simply identify the location of the strongest electric field.
Van Hoornweder S, Beck MM, Nielsen JD, Tomasevic L, Meesen RLJ, Siebner HR, Thielscher A.
Imaging neuroscience (Cambridge, Mass.) · Publication date: 2026-09-10
Added to site: 2026-09-16
DOI: 10.1162/imag.a.1356
Original publication date verified from the authoritative indexed record; separate from the date added to this site.
- Modalities
- TMS, EEG, eLORETA
- Clinical focus
- Brain stimulation, Source localization
- Population
- Healthy younger adults
- Sample
- 16 of 28 screened adults; 12 excluded because of muscle artifacts
- Intervention / method
- Motor-cortex TMS at six intensities during rest and contraction; MRI-based electric fields and three inverse solvers
- Comparator
- Stimulation dose and motor state; LCMV, dSPM and eLORETA source estimates
Clinician summary
N15 sources lay anterior to peak modeled fields; the separation narrowed with increasing dose. Three solvers produced similar patterns.
How to interpret the findings
Small selected sample; coil positions were interpolated for nine participants. One omitted the highest intensity because of discomfort. Model assumptions and residual artifacts matter; no clinical benefit was tested.
Equipment and disclosures
MRI-guided field modeling and TMS-EEG; no sponsor-equipment attribution.
Full-text sections identify Research Foundation Flanders, Innovation Fund Denmark, dtec.bw and Lundbeck Foundation support. Authors declare no competing interests. Abstract plus participant, limitation and disclosure sections checked.
Related evidence
Compare findings from the same clinical area, including mixed results.
- Real-time measurement instead of prediction enables high-precision phase-specific stimulation of the human brain. · Positive with limitations
- Bridging Temporal and Spatial Scales: Contemporary Advances in EEG-fMRI Integration With a Focus on Epilepsy. · Positive with limitations
Summary prepared with AI assistance. Source verification does not imply an independent replication or a clinician's endorsement. Read our review method.