NCT07663578 · University of California, Davis
Cognitive and Electrophysiological Assessment of Non-Invasive Temporally-Interfering Electric Fields Stimulation (TIEFS)
(TIEFS)
What this study is about
The goal of this clinical trial is to learn how a non-invasive brain stimulation method called Temporally Interfering Electric Fields Stimulation (TIEFS) affects brain activity and thinking in adults. TIEFS uses electrical currents applied to the scalp to influence brain activity without surgery.
View original scientific description
The goal of this clinical trial is to learn how a non-invasive brain stimulation method called Temporally Interfering Electric Fields Stimulation (TIEFS) affects brain activity and thinking in adults. TIEFS uses electrical currents applied to the scalp to influence brain activity without surgery. The main questions this study aims to answer are: * How does TIEFS change brain signals measured with brain recordings? * Does TIEFS affect thinking abilities such as memory, language, movement, or perception? * Is TIEFS safe and well tolerated when used in people? This study includes two groups of participants. One group includes adults with epilepsy who are already undergoing specialized brain monitoring as part of their medical care. The other group includes healthy adults with no history of seizures. Participants will: * Receive brief sessions of TIEFS using electrodes placed on the scalp * Complete computer-based tasks that test memory, attention, language, or movement. Answer questions about how the stimulation feels * Have brain activity recorded during the study Each study visit lasts up to three hours and may occur in one or two sessions. Information from this study may help researchers better understand the human brain and support the development of future non-invasive brain stimulation treatments.
Interventions
DEVICE
Temporal Interference Electrical Stimulation
Temporal Interference Electrical Stimulation (TIEFS) is a non-invasive brain stimulation technique that uses two high-frequency electrical fields (\>1 kHz) to generate an interference pattern at a specific brain region, creating a low-frequency envelope (Δf = f2 - f1) at the target depth. Unlike traditional stimulation methods, which affect only superficial brain regions, TIEFS can reach deeper structures without the need for implanted electrodes. The stimulation is applied through scalp electrodes. It has the potential for targeted brain interventions in both functional studies and clinical applications for neurological conditions.
Primary outcome measures
Brain activity changes during Stimulation
Time frame: Measurements will be recorded throughout the stimulation session (lasting up to 90 minutes), with data collected before, during, and immediately after each stimulation.
This outcome measures the changes in brain activity, either measured through scalp EEG electrodes (in Healthy Participant controls), or intracranial stereotaxic EEG electrodes (for SEEG pre-surgical evaluation epilepsy patients). Local field potential (LFP) power and EEG power in response to active TIEFS stimulation will be compared to sham stimulation. Electrical signals recorded from the brain reflect neural activity. Intracranial signals will be measured across different locations in the brain using implanted SEEG electrodes. Additionally, SEEG electrodes may have tetrodes tips to capture single neuron activity. We will compare how the brain's electrical activity changes during active TIEFS at various frequencies and during the sham stimulation to assess the impact on brain and neural function.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Adult patients (age 18-65 years of age) undergoing an intracerebral electrophysiology study for epilepsy pre-surgical evaluation are eligible for inclusion.
- For healthy control subjects are also eligible for inclusion (Scalp EEG measurements).
- Participants must be able to sufficiently speak and understand English or Spanish for consent and be able to understand and complete cognitive tasks.
- All subjects must have the ability to give valid informed consent.
Exclusion criteria
- No pregnant women will be recruited.
- People with implanted electrical devices such as Deep Brain Stimulation devices or Pacemakers.
- No prisoners will be recruited.
Where
- Sacramento, California
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 23, 2026 · Source of record for eligibility and locations