Healthy Participants
Conditions
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.
Interventions
DEVICEtranscutaneous auricular vagus nerve stimulation
Ear clip electrodes attached to the left cymba conchae to target vagus nerve branches.
DEVICESham condition
Electrode placement attached on the left earlobe.
Sponsors
University of Electronic Science and Technology of China
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Neural activity changes between groups | 10 minutes | The differences in the activity of frontal regions between groups using fNIRS |
| Fear ratings between groups | 10 minutes | The differences in the fear ratings (0-100, from neutral to extremely fearful) between groups |
| Functional connectivity witnin frontal regions between groups | 10 minutes | The differences in the functional connectivity within frontal regions using fNIRS between groups |
| The correlation between brain activity and behavioral ratings across groups | 10 minutes | The correlation between brain activity and behavioral ratings across groups |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Skin conductance response between groups | 10 minutes | The differences in the skin conductance response during watching video between groups |
Countries
China
Outcome results
None listed