Brief Summary

Transcranial temporal interference stimulation (TIS) is an emerging novel tool for non-invasive transcranial brain stimulation that holds the potential for focal and steerable neuromodulation, and the possibility to stimulate focally at depth. TIS involves combining two high frequency waveforms to create a waveform with a "beat" frequency that is physiological relevant for neuromodulation. Successful applications to deep brain targets as well as steerability of the stimulation focus have been demonstrated in mice. Numerous recent investigations in humans have shown great clinical potential for this technology, however several questions about the basic mechanism of TIS action remain. The investigators will apply TIS to the motor cortex of humans and use established transcranial magnetic stimulation techniques to assess cortical excitability in relation to the phase of the TIS waveform. Using TMS, the investigators will i) validate that effects of TIS are due to the "beat" frequency and not the high frequency carrier signal, ii) evaluate the effect of the TIS carrier frequency, and iii) evaluate that whether changes in corticospinal excitability outlast the period of stimulation. Knowledge gained from this experiment will provide a basis for the future use of TIS for clinical applications, including informing parameter optimization.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

participants targeted

Target at below P25 for not_applicable

Timeline

41mo left

Started Feb 2026

Longer than P75 for not_applicable

Geographic Reach

1 country

1 active site

Status

recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

3.7 years study duration

Study Progress8%

Feb 2026Oct 2029

Study Start

First participant enrolled

February 1, 2026

Completed

3 months until next milestone

First Submitted

Initial submission to the registry

May 5, 2026

Completed

13 days until next milestone

First Posted

Study publicly available on registry

May 18, 2026

Completed

3.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

October 1, 2029

Expected

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

October 1, 2029

Last Updated

May 18, 2026

Status Verified

May 1, 2026

Enrollment Period

3.7 years

First QC Date

May 5, 2026

Last Update Submit

May 14, 2026

Conditions

Healthy Adult Participants

Keywords

transcranial temporal interference stimulation

Outcome Measures

Primary Outcomes (1)

Online phase-dependent modulation of corticospinal excitability using the relevance value (R.V.)
Explained variance (R2) of best-fit sinusoids will be multiplied by the variance of measured values to obtain the established "relevance value" (R.V.), to be used as our primary outcome. Relevance values assume phase-dependent modulation with a large amplitude is more meaningful than one with small amplitude and the same R2. Critically, phase-dependent responses to TIS represent direct evidence of modulation at beat frequency (fb).
Periprocedural

Secondary Outcomes (2)

Offline neuroplastic effects from pre to post
Periprocedural
Offline neuroplastic post effects
Periprocedural