The main aim of this study is to investigate whether transcutaneous auricular vagus nerve stimulation (taVNS) can reduce anxiety and have an effect on emotional regulations
Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive method for modulating vagal nerve function and has shown potential efficacy in alleviating anxiety symptoms and improving emotional regulation. But the neural mechanisms of how taVNS affects anxiety and emotional regulation remain unclear. Therefore, we focus on this question by combining behavioral meausres, skin conductance response, heart rate variability and fMRI in this study. A participant-blinded, sham-controlled, between-subject design is employed in this study. In a randomised order, a total of 140 healthy males and females with or without high trait anxiety are recruited and receive the stimulation of taVNS on their tragus (experimental group) or earlobe (sham control group). After the participants arrive at the laboratory, they first complete a roughly 30-minute personality trait questionnaire and prepare for the experiment. Then, they undergo a 7-minute resting-state fMRI scan, followed by a 15-minute taVNS session. Next, they complete a 7-minute resting-state scan and a 60-minute task-based scan (a modified emotional regulation task). During the entire procedure, saliva samples will be collected three times for subsequent physiological hormone analyses, and participants' skin conductance and electrocardiogram data will also be recorded. During the modified emotional regulation task, subjects are instructed to regulate their emotional responses to negative pictures (high vs. low intensity) using reinterpretation/distance strategies or to only look these pictures. We also record subjects' rating scores on their anxiety levels during these conditions ("reinterpretation" vs. "distance" vs. "look") and successful usage of emotional regulation strategies. Questionnaire scores including State-Trait Anxiety Inventory, Beck Depression Inventory II, Beck Anxiety Inventory, Autism Spectrum Quotient, Toronto Alexithymia Scale, Social Responsiveness Scale, Emotion Regulation Questionnaire, Cognitive Emotion Regulation Questionnaire, Multidimensional Assessment of Interoceptive Awareness, Positive and Negative Affect Schedule will also be collected.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Enrollment
140
15 minutes taVNS on tragus
15 minutes taVNS on earlobe
15 minutes taVNS on tragus
University of Electronic Science and Technology of China (UESTC)
Chengdu, Sichuan, China
RECRUITINGBrain activity patterns in response to negative pictures during emotional regulation
Subjects will receive task-based fMRI scanning (i.e., the modified emotional regulation task) after taVNS and two resting-state fMRI scanning sessions. We will examine these brain response patterns in the modified emotional regulation task via both the conventional univariate analysis and the machine learning-based multivariate pattern analysis.
Time frame: 60 minutes
Resting-state functional conetivity changes
Subjects will receive resting-state fMRI scanning twice before and after taVNS. We will examine resting-state functional conetivity changes induced by taVNS via examining functional conetivity differences between pre- and post-taVNS sessions.
Time frame: 15 minutes
Behavioral indices in the task
Anxiety and success ratings after each regulation trial are recorded in the task. Subjects are instructed to rate their anxiety and success levels using a 9-point Likert scale within 4 seconds (1 = not at all, 9 = very anxious or successful)
Time frame: 60 minutes
Skin conductance responses (SCR) in the emotional regulation task during fMRI scanning
Skin Conductance Response (SCR) data in response to negative pictures while using different regulation strategies are recorded in the emotional regulation task.
Time frame: 60 minutes
HRV in resting-state fMRI and emotional regulation task
Heart beat variability (HRV) data are recorded in resting-state fMRI and emotional regulation task.
Time frame: 75 minutes during scanning
Saliva samples analysis
Saliva samples will be collected three times for subsequent physiological hormone analysis.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
15 minutes taVNS on earlobe
Time frame: Three time points: pre-taVNS (baseline, 0 minute), immediate post-taVNS (60 minutes post-taVNS), and the end of experiment (70 minutes post-scanning).