Effects of Transcutaneous Auricular Vagus Nerve Stimulation on Cognitive Performance and Sex Differences
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Active taVNS, Sham Stimulation.
- Who it may be relevant to
- Registry conditions: Cognitive Assessment, Cognition, taVNS, Vagus Nerve Stimulation. Basic parameters: 18 years — 30 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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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
Overview
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.
Interventions
- Device Active taVNS
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. - Device Sham Stimulation
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.
Primary outcome measures
- 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.]
Secondary outcome measures (4)
- 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)]
Eligibility criteria
Inclusion criteria
- 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
Exclusion criteria
- 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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Crossover
- Masking
- Double blind
- Primary purpose
- Basic science
Study locations
Center list to be confirmed — check the primary protocol.
Identifiers
NCT: NCT07256080 · 61351342/020-93