Cognitive AssessmentNCT07256080
Effects of Transcutaneous Auricular Vagus Nerve Stimulation on Cognitive Performance and Sex Differences
A study testing Active taVNS in people with Cognitive Assessment and Cognition, run by Bahçeşehir University.
Trial summary
This study investigates the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on cognitive performance in healthy adults. The study uses a sham-controlled, cross-over design in which each participant receives both active taVNS and sham stimulation in separate sessions. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Cognitive Assessment, Cognition, taVNS
- What is being tested?
- Active taVNS
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- No sites listed yet
- Study dates
- Dec 2025to May 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy young adults aged 18-30 years
- Ability to provide informed consent
- Right-handed participants (to reduce variability in cognitive performance)
- Normal or corrected-to-normal vision and hearing
- Female participants tested during the follicular phase of the menstrual cycle (days 5-10) to minimize hormonal effects on cognition and vagal tone
Who cannot join
- History of neurological or psychiatric disorders
- Cardiovascular disease
- Use of psychoactive medications
- Substance dependence, including alcohol, illicit drugs, or nicotine
- Pregnancy or breastfeeding
- Skin conditions or ear anomalies that interfere with electrode placement
- Metal implants in the head or neck region
- History of epilepsy or migraine
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: A Sham-Controlled Cross-Over Study Examining the Effects of Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) on Cognitive Performance and Gender Differences in Healthy Adults
This study investigates the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on cognitive performance in healthy adults. The study uses a sham-controlled, cross-over design in which each participant receives both active taVNS and sham stimulation in separate sessions. Each participant completes both conditions (active and sham) in a randomized order using a crossover design. Cognitive performance will be assessed before and after each session using standardized tests. The study also explores whether males and females respond differently to taVNS, in order to identify potential sex-related differences in cognitive outcomes.
Read the detailed description
This randomized, sham-controlled cross-over study investigates the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on cognitive performance, autonomic activity, and psychological state in healthy young adults, with specific attention to sex differences. Because hormonal fluctuations may influence vagal tone and cognitive outcomes, female participants are required to complete their stimulation sessions during the follicular phase (Day 5-10) of the menstrual cycle. Male participants follow the same protocol without timing restrictions.
The study consists of three laboratory visits, scheduled one week apart.
Visit 1 (Baseline Assessments):
Participants provide informed consent and complete a demographic questionnaire, menstrual-cycle verification (for female participants), the Montreal Cognitive Assessment (MoCA), and baseline psychological questionnaires including the State-Trait Anxiety Inventory (STAI) and the Perceived Stress Scale (PSS). Baseline cognitive performance is measured using the CogniFit digital battery.
Visits 2 and 3 (Randomized Cross-Over Stimulation Sessions):
Participants undergo active taVNS and sham stimulation in randomized order. At the beginning of each visit, heart rate variability (HRV) is recorded for 5 minutes before stimulation to establish a resting baseline. Stimulation is applied for 20 minutes using the VaguStim device. Immediately after stimulation, HRV is recorded again for 5 additional minutes, followed by completion of a side-effect questionnaire documenting any sensations or adverse reactions. Following that, participants complete the STAI and PSS questionnaires to assess post-stimulation psychological state.Cognitive performance is then reassessed using the CogniFit digital battery.
This cross-over design enables within-subject comparison between active and sham stimulation and provides the structure needed to examine potential sex-related differences in autonomic, cognitive, and psychological responses to taVNS.
- Conditions
- Cognitive Assessment, Cognition, taVNS, Vagus Nerve Stimulation, Executive Functions, Healthy Participants
- Being tested
- Active taVNS, Sham Stimulation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Active taVNSDevice
Active taVNS will be delivered bilaterally to the cymba conchae and tragus regions using the VaguStim device. Stimulation parameters follow cognitive-neuroscience standards to minimize cardiac side effects: biphasic waveform, 25 Hz frequency, 250 μs pulse width, and intensity individually adjusted below the sensory threshold (0.5-4 mA). Each stimulation session lasts 20 minutes.
This intervention corresponds to the Active taVNS Stimulation arm.
Sham StimulationDevice
Sham stimulation will be delivered using the same VaguStim device, but electrodes will be placed bilaterally on the earlobe, an area not innervated by the vagus nerve. Device parameters will be set to match the active condition, but no true vagus nerve stimulation is delivered. This procedure controls for placebo and participant expectancy effects.
This intervention corresponds to the Sham Stimulation arm.
| Study group | Role | What they receive |
|---|---|---|
| Active taVNS Stimulation | Experimental | Active taVNS will be applied bilaterally to the cymba conchae and tragus regions using the VaguStim device. Stimulation will follow standard parameters used in cognitive studies to minimize cardiac side effects. Parameters: biphasic waveform, 25 Hz frequency, 250 μs pulse width, and intensity individually adjusted below the sensory threshold (0.5-4 mA). Each session will last 20 minutes. Receives: Device: Active taVNS |
| Sham Stimulation | Sham comparator | For the sham condition, electrodes will be placed on the earlobe bilaterally, an area not innervated by the vagus nerve, using the same device and parameter settings but without delivering active stimulation. This setup controls for placebo effects. Receives: Device: Sham Stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
CogniFit Digital Battery
Cognitive performance will be evaluated using the CogniFit digital cognitive battery, which assesses multiple cognitive domains including attention, working memory, executive functions, and processing speed.
The battery will be administered once at baseline (Visit 1). It will be administered again immediately after Active stimulation in Visit 2 and immediately after Sham stimulation in Visit 3.
Changes in cognitive scores between baseline and post-stimulation sessions will be compared to determine the acute cognitive effects of active vs. sham taVNS.
Measured: Day 1 (Visit 1 baseline), Day 8 (Visit 2), and Day 15 (Visit 3) Cognitive testing will occur after stimulation on Day 8 and Day 15.
Secondary outcomes (4)
Heart Rate Variability (HRV)
Heart rate variability will be assessed using the Polar H10 chest strap or another validated portable HRV device widely used in research. Five-minute recordings will be obtained during resting state and during stimulation. Time-domain parameters (RMSSD, SDNN) and frequency-domain parameters (LF/HF ratio) will be analyzed.
Measured: Day 8 (Visit 2): 5 minutes before stimulation and 5 minutes after stimulation. Day 15 (Visit 3): 5 minutes before stimulation and 5 minutes after stimulation.
Perceived Stress Levels (PSS)
The Perceived Stress Scale (PSS) will assess participants' perceived stress levels over the past month. Higher scores indicate higher perceived stress.
Measured: Day 1 (Visit 1 baseline), Day 8 (Visit 2 after stimulation), and Day 15 (Visit 3 after stimulation).
State and Trait Anxiety (STAI)
The State-Trait Anxiety Inventory (STAI) will measure acute state anxiety (STAI-S) and general trait anxiety (STAI-T).
Measured: Day 1 (Visit 1 baseline), Day 8 (Visit 2 after stimulation), and Day 15 (Visit 3 after stimulation).
Self-Reported Side Effects
A researcher-developed side-effects questionnaire will be used to record any discomfort, tingling, dizziness, or other adverse effects following stimulation.
Measured: Day 8 (Visit 2 after stimulation) and Day 15 (Visit 3 after stimulation)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Dec 2025
- Study startDec 2025 (estimated)
- Primary completionApr 2026 (estimated)
- Study completionMay 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cognitive AssessmentStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Bahçeşehir University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Yara Atef Skout, Bahçeşehir University
- Investigators
- Ali Veysel Ozden, Study chair, Bahçeşehir University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07256080
- Sponsor's protocol ID
- 61351342/020-93
- Status last verified
- Nov 2025
- First submitted
- 18 Nov 2025
- Last updated
- 1 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Sham-Controlled Cross-Over Study Examining the Effects of Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) on Cognitive Performance and Gender Differences in Healthy Adults
- ClinicalTrials.gov ID
- NCT07256080
- Acronym / sponsor ID
- 61351342/020-93
- Conditions
- Cognitive Assessment, Cognition, taVNS, Vagus Nerve Stimulation, Executive Functions, Healthy Participants
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Bahçeşehir UniversityUniversity, hospital or other
- Study start
- Dec 2025 (estimated)
- Primary completion
- Apr 2026 (estimated)
- Study completion
- May 2026 (estimated)
- First posted
- 1 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study investigates the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on cognitive performance in healthy adults. The study uses a sham-controlled, cross-over design in which each participant receives both active taVNS and sham stimulation in separate sessions. Each participant completes both conditions (active and sham) in a randomized order using a crossover design. Cognitive performance will be assessed before and after each session using standardized tests. The study also explores whether males and females respond differently to taVNS, in order to identify potential sex-related differences in cognitive outcomes.
Detailed description
This randomized, sham-controlled cross-over study investigates the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on cognitive performance, autonomic activity, and psychological state in healthy young adults, with specific attention to sex differences. Because hormonal fluctuations may influence vagal tone and cognitive outcomes, female participants are required to complete their stimulation sessions during the follicular phase (Day 5-10) of the menstrual cycle. Male participants follow the same protocol without timing restrictions.
The study consists of three laboratory visits, scheduled one week apart.
Visit 1 (Baseline Assessments):
Participants provide informed consent and complete a demographic questionnaire, menstrual-cycle verification (for female participants), the Montreal Cognitive Assessment (MoCA), and baseline psychological questionnaires including the State-Trait Anxiety Inventory (STAI) and the Perceived Stress Scale (PSS). Baseline cognitive performance is measured using the CogniFit digital battery.
Visits 2 and 3 (Randomized Cross-Over Stimulation Sessions):
Participants undergo active taVNS and sham stimulation in randomized order. At the beginning of each visit, heart rate variability (HRV) is recorded for 5 minutes before stimulation to establish a resting baseline. Stimulation is applied for 20 minutes using the VaguStim device. Immediately after stimulation, HRV is recorded again for 5 additional minutes, followed by completion of a side-effect questionnaire documenting any sensations or adverse reactions. Following that, participants complete the STAI and PSS questionnaires to assess post-stimulation psychological state.Cognitive performance is then reassessed using the CogniFit digital battery.
This cross-over design enables within-subject comparison between active and sham stimulation and provides the structure needed to examine potential sex-related differences in autonomic, cognitive, and psychological responses to taVNS.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Active taVNS Stimulation | Experimental | Device: Active taVNSActive taVNS will be applied bilaterally to the cymba conchae and tragus regions using the VaguStim device. Stimulation will follow standard parameters used in cognitive studies to minimize cardiac side effects. Parameters: biphasic waveform, 25 Hz frequency, 250 μs pulse width, and intensity individually adjusted below the sensory threshold (0.5-4 mA). Each session will last 20 minutes. |
| Sham Stimulation | Sham comparator | Device: Sham StimulationFor the sham condition, electrodes will be placed on the earlobe bilaterally, an area not innervated by the vagus nerve, using the same device and parameter settings but without delivering active stimulation. This setup controls for placebo effects. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Healthy young adults aged 18-30 years
- Ability to provide informed consent
- Right-handed participants (to reduce variability in cognitive performance)
- Normal or corrected-to-normal vision and hearing
- Female participants tested during the follicular phase of the menstrual cycle (days 5-10) to minimize hormonal effects on cognition and vagal tone
Key exclusion criteria (8 listed)
- History of neurological or psychiatric disorders
- Cardiovascular disease
- Use of psychoactive medications
- Substance dependence, including alcohol, illicit drugs, or nicotine
- Pregnancy or breastfeeding
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Active taVNSActive taVNS will be delivered bilaterally to the cymba conchae and tragus regions using the VaguStim device. Stimulation parameters follow cognitive-neuroscience standards to minimize cardiac side effects: biphasic waveform, 25 Hz frequency, 250 μs pulse width, and intensity individually adjusted below the sensory threshold (0.5-4 mA). Each stimulation session lasts 20 minutes. This intervention corresponds to the Active taVNS Stimulation arm. | Device | Active taVNS Stimulation |
| Sham StimulationSham stimulation will be delivered using the same VaguStim device, but electrodes will be placed bilaterally on the earlobe, an area not innervated by the vagus nerve. Device parameters will be set to match the active condition, but no true vagus nerve stimulation is delivered. This procedure controls for placebo and participant expectancy effects. This intervention corresponds to the Sham Stimulation arm. | Device | Sham Stimulation |
Primary outcome
CogniFit Digital Battery
Time frame: Day 1 (Visit 1 baseline), Day 8 (Visit 2), and Day 15 (Visit 3) Cognitive testing will occur after stimulation on Day 8 and Day 15.
Cognitive performance will be evaluated using the CogniFit digital cognitive battery, which assesses multiple cognitive domains including attention, working memory, executive functions, and processing speed. The battery will be administered once at baseline (Visit 1). It will be administered again immediately after Active stimulation in Visit 2 and immediately after Sham stimulation in Visit 3. Changes in cognitive scores between baseline and post-stimulation sessions will be compared to determine the acute cognitive effects of active vs. sham taVNS.
4 secondary outcomes
Heart Rate Variability (HRV)
Time frame: Day 8 (Visit 2): 5 minutes before stimulation and 5 minutes after stimulation. Day 15 (Visit 3): 5 minutes before stimulation and 5 minutes after stimulation.
Perceived Stress Levels (PSS)
Time frame: Day 1 (Visit 1 baseline), Day 8 (Visit 2 after stimulation), and Day 15 (Visit 3 after stimulation).
State and Trait Anxiety (STAI)
Time frame: Day 1 (Visit 1 baseline), Day 8 (Visit 2 after stimulation), and Day 15 (Visit 3 after stimulation).
Self-Reported Side Effects
Time frame: Day 8 (Visit 2 after stimulation) and Day 15 (Visit 3 after stimulation)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Dec 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Ali Veysel Ozden study chair
Bahçeşehir University
Questions about this trial
What is this clinical trial studying?
A study testing Active taVNS in people with Cognitive Assessment and Cognition, run by Bahçeşehir University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 1 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Yara A Skout (+905316766782, yaraskout@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
CogniFit Digital Battery (time frame: Day 1 (Visit 1 baseline), Day 8 (Visit 2), and Day 15 (Visit 3) Cognitive testing will occur after stimulation on Day 8 and Day 15.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Dec 2025.