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Effects of Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) on Cognition, Dual-Task Performance, and Interoceptive Accuracy
Sponsor: Toros University
Summary
This study aims to determine the simultaneous effects of transcutaneous auricular vagus nerve stimulation (taVNS) at two frequencies (30 Hz and 100 Hz) compared to sham stimulation on cognitive functions, dual-task performance, and interoceptive accuracy in healthy adults. taVNS non-invasively activates vagal afferent fibers through electrical stimulation of the outer ear (cymba conchae and tragus), which are exclusively innervated by the auricular branch of the vagus nerve. Its proposed mechanism involves activation of the locus coeruleus-norepinephrine system and insular/prefrontal projections, providing a putative neurobiological basis for cognitive modulation. Ninety healthy volunteers (18-45 years) will be randomly assigned to one of three parallel groups: sham taVNS (n=30), active 30 Hz taVNS (n=30), or active 100 Hz taVNS (n=30). Each participant completes two sessions separated by one week: Session 1 (baseline, no stimulation) and Session 2 (experimental, stimulation active). Assessments include dual-task cost (3-Meter Tandem Walk Test with serial subtraction), executive function (Stroop Test), processing speed (Deary-Liewald Reaction Time Task), interoceptive accuracy (Heartbeat Counting Task), and heart rate variability (Polar H10). Sleep quality (PSQI), depression (BDI), physical activity (IPAQ-SF), and fatigue (Chalder Fatigue Scale) are measured at baseline as potential moderators. This is the first double-blind, sham-controlled study to simultaneously evaluate the effects of taVNS on these three constructs within a single experimental design, and the comparative frequency analysis (30 Hz vs 100 Hz) will contribute to parameter optimization for taVNS applications.
Official title: Simultaneous Effects of Transcutaneous Auricular Vagus Nerve Stimulation on Cognitive Functions, Dual-Task Performance, and Interoceptive Accuracy: A Double-Blind, Sham-Controlled, Randomized Parallel-Group Study
Key Details
Gender
All
Age Range
18 Years - 45 Years
Study Type
INTERVENTIONAL
Enrollment
54
Start Date
2026-11-01
Completion Date
2027-05-01
Last Updated
2026-10-27
Healthy Volunteers
Yes
Conditions
Interventions
Sham Stimulation
Sham transcutaneous auricular vagus nerve stimulation delivered via Vagustim® non-invasive stimulation device (CE No: 2460; Vagustim Health Technologies Inc., Turkey). Electrode placement is identical to active groups: bilateral cymba conchae and tragus using custom-sized auricular electrodes (small/medium/large). The device is switched on and electrodes are positioned in the same manner, but no electrical current is delivered. Session duration and all procedural steps are identical to active arms to maintain blinding. Participants are not informed of group allocation. The outcome assessor is blinded to group assignment throughout the study.
taVNS 30 Hz
Active transcutaneous auricular vagus nerve stimulation at 30 Hz delivered via Vagustim® non-invasive stimulation device (CE No: 2460; Vagustim Health Technologies Inc., Turkey). Electrode placement: bilateral cymba conchae and tragus using custom-sized auricular electrodes (small/medium/large). Parameters: frequency 30 Hz, pulse width 250 µs, continuous mode, current intensity individually titrated to a perceptible but sub-pain threshold. Stimulation is applied online (throughout the experimental session) during all outcome assessments. The outcome assessor is blinded to group allocation; stimulation is administered by a separate researcher not involved in assessments.
taVNS 100 Hz
Active transcutaneous auricular vagus nerve stimulation at 100 Hz delivered via Vagustim® non-invasive stimulation device (CE No: 2460; Vagustim Health Technologies Inc., Turkey). Electrode placement: bilateral cymba conchae and tragus using custom-sized auricular electrodes (small/medium/large). Parameters: frequency 100 Hz, pulse width 250 µs, continuous mode, current intensity individually titrated to a perceptible but sub-pain threshold. Stimulation is applied online (throughout the experimental session) during all outcome assessments. The outcome assessor is blinded to group allocation; stimulation is administered by a separate researcher not involved in assessments.
Locations (1)
Toros University 45 Evler Campus
Mersin, Turkey (Türkiye)