Actively Recruiting
tVNS and Approach-Avoidance Behavior in Anhedonia and Anxiety
Led by Dr. Nils B. Kroemer · Updated on 2026-04-23
104
Participants Needed
1
Research Sites
144 weeks
Total Duration
On this page
Sponsors
D
Dr. Nils B. Kroemer
Lead Sponsor
U
University of Bonn
Collaborating Sponsor
AI-Summary
What this Trial Is About
This study investigates if anhedonia and anxiety symptoms are associated with alterations in reinforcement learning, effort trade-offs for wins vs. punishments, and foraging behavior under threat. Moreover, it will investigate whether these processes can be influenced by a metabolic load and/or transcutaneous vagus nerve stimulation (tVNS). The project consists of (a) an online reinforcement learning study, used to characterize learning, reward sensitivity, and meta-cognition, and (b) a laboratory study in which participants first undergo fMRI while completing an effort-based decision-making task. Second, participants will complete two sessions in VR with randomized active or sham tVNS during a foraging task before and after a caloric load with concurrent physiological recordings.
CONDITIONS
Official Title
tVNS and Approach-Avoidance Behavior in Anhedonia and Anxiety
Who Can Participate
Eligibility Criteria
You may qualify if you...
- BMI between 18.5 and 30.0 kg/m2
- Age between 18 and 40 years
- Able and willing to provide informed consent
You will not qualify if you...
- High risk of suicide
- Lifetime diagnosis of severe neurological disorder (including ADHD), schizophrenia, bipolar disorder, severe substance abuse, posttraumatic stress disorder, obsessive-compulsive disorder, diabetes, epilepsy, or coronary heart disease
- Diagnosis of eating disorder or somatic symptom disorder within the last 12 months
- Taking medication other than stable psychopharmacological medication for major depressive disorder or anxiety (stable for at least two months before participation)
- Contraindications for MRI such as metal implants or claustrophobia
- Pregnant or nursing female individuals
- Impaired movement ability or hearing
- Impaired, uncorrected vision (need contact lenses)
- Contraindications for tVNS such as hearing aids or diseased skin on the right ear
AI-Screening
AI-Powered Screening
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Trial Site Locations
Total: 1 location
1
University Hospital Bonn, Bonn, Germany
Bonn, Germany, 53127
Actively Recruiting
Research Team
D
Dr. Anne Kühnel
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
SINGLE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
BASIC_SCIENCE
Number of Arms
4
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