Clinical trial NCT06975124: taVNS Effects on Fear Ratings in Naturalistic Context
Official title: taVNS Effects on Fear Ratings in Naturalistic Context
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: PHASE1
Conditions: Healthy Participants
Lead sponsor: University of Electronic Science and Technology of China
Sponsor class: OTHER
First posted: 2025-05-16
Enrollment: 70
Sex: ALL
Minimum age (years): 18
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: During the fear rating task, 70 participants viewed a 600-second horror movie while continuously rating their subjective fear intensity (0-100 scale) every 0.51 seconds (1,170 total ratings). Functional near-infrared spectroscopy (fNIRS) data were simultaneously recorded using the NIRSIT LITE system to monitor cortical hemodynamic responses.

Detailed description: In a sham-controlled, participant-blinded, between-subjects design, 70 participants were randomly assigned to either active transcutaneous auricular vagus nerve stimulation (taVNS) or sham stimulation. The taVNS group received stimulation via a modified transcutaneous electrical acupoint stimulation device, with ear clip electrodes attached to the left cymba conchae to target vagus nerve branches. The sham group received identical electrode placement on the left earlobe, a non-vagus-innervated site. Stimulation intensity was individually calibrated to a perceptible but non-painful level to ensure vagal activation while maintaining participant comfort.

Upon arrival, all participants completed standardized mood and trait questionnaires. To assess emotional and physiological changes, two administrations of the Positive and Negative Affect Schedule (PANAS) and blood pressure/pulse measurements (pre- and post-intervention) were conducted. During the fear rating task, participants viewed a 600-second horror movie while continuously rating their subjective fear intensity (0-100 scale) every 0.51 seconds (1,170 total ratings). Functional near-infrared spectroscopy (fNIRS) data were simultaneously recorded using the NIRSIT LITE system to monitor cortical hemodynamic responses. Additionally, skin conductance responses were measured vy BIOPAC MP150 system.

Eligibility criteria: Inclusion Criteria:

Healthy participants without color blindness, current or regular substance or medication use, any current or history of medical or psychiatric disorders and contraindications for MRI.

Exclusion Criteria:

* Color blindness,
* Current or regular substance or medication use
* any current or history of medical or psychiatric disorders and contraindications for MRI

Primary outcomes:
measure: Neural activity changes between groups
timeFrame: 10 minutes
measure: Fear ratings between groups
timeFrame: 10 minutes
measure: Functional connectivity witnin frontal regions between groups
timeFrame: 10 minutes
measure: The correlation between brain activity and behavioral ratings across groups
timeFrame: 10 minutes
Secondary outcomes:
measure: Skin conductance response between groups
timeFrame: 10 minutes
Other outcomes:
Locations:
city: Chengdu
country: China
facility: Nirsit Lite
state: Sichuan
Study officials:
References: