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tVNS and Approach-Avoidance Behavior in Anhedonia and Anxiety
Sponsor: Dr. Nils B. Kroemer
Summary
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.
Official title: Vagus Nerve Stimulation and Approach-Avoidance Behavior in Anhedonia and Anxiety
Key Details
Gender
All
Age Range
18 Years - 40 Years
Study Type
INTERVENTIONAL
Enrollment
104
Start Date
2026-02-20
Completion Date
2028-12-31
Last Updated
2026-03-17
Healthy Volunteers
Yes
Conditions
Interventions
tVNS
The intervention consists of event-triggered tVNS in the form of short pulses (\~1-5s; frequency: 25Hz). A non-CE-certified and non-medical device (tVNS® R tVNS technologies, for research purposes) will be used. Stimulation intensity will be individually calibrated to ensure perceptible (mild pricking) but non-painful stimulation for each participant. The protocol is the same for all groups.
Sham
The sham condition similarly consists of event-triggered, closed-loop stimulation, but without vagus nerve activation (short pulses of 1-5s; frequency: 25Hz). A non-CE-certified and non-medical device (tVNS® R, for research purposes) will be used. The manufacturer is not involved in the study. Stimulation intensity will be individually calibrated to ensure perceptible (mild pricking) but non-painful stimulation for each participant. The protocol is the same for all groups.
Locations (1)
University Hospital Bonn, Bonn, Germany
Bonn, Germany