Healthy men
Conditions
Interventions
Group 1: Testosteron Increase (Testosteron-Gel nach GnRH-Antagonist)
Group 2: Testosteron Suppression (GnRH-Antagonist + Placebo Gel)
Group 3: Placebo (Placebo-Injection + Placebo-Gel)
Sponsors
Uniklinik RWTH Aachen
Eligibility
Sex/Gender
Male
Age
18 Years to 40 Years
Inclusion criteria
Inclusion criteria: Healthy physical and mental condition Normal or corrected vision (glasses/contact lenses allowed) No hormonal imbalance or endocrine disorders Willingness to participate in fMRI measurements and hormonal manipulations No medication use affecting the hormonal system
Exclusion criteria
Exclusion criteria: Current or past psychiatric disorders (e.g., depression, anxiety disorders, schizophrenia) Hormonal disorders or endocrine diseases (e.g., hypogonadism, hyperthyroidism, diabetes mellitus) Cardiovascular diseases or known intolerance to testosterone or GnRH antagonists Use of medications affecting the hormonal system or central nervous system Alcohol or drug abuse in the past six months Metal implants or other contraindications for fMRI (e.g., pacemakers, cochlear implants, non-removable piercings) Left-handedness (as neural activation patterns in right-handers are being studied)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 1.Effects of experimental context modulation on threat processing, measured by: • Amygdala activation (from the threat sensitivity task) • Behavioral response biases toward threat • Neural and behavioral responses to peripersonal space (PPS) intrusions 2.Interaction of context and testosterone levels on threat processing, with the hypothesis: • High testosterone (T) levels enhance threat responses. • Low T levels attenuate threat responses. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Hostility bias in the threat bias task: Participants will view images depicting social interactions with varying levels of ambiguity (e.g., a raised hand could be aggressive or friendly). After each image, they will: • Select the most likely outcome (aggressive/neutral/friendly). • Rate their subjective feeling of threat on a scale from 1 to 10. • Task duration: 10 minutes per session, conducted inside the MRI scanner following the contextual manipulation. 2. Neural and behavioral responses to potential threats and PPS intrusions: • VR-based PPS Task: Participants will passively observe 3D videos of an approaching character while undergoing fMRI scanning. • Prefrontal-limbic circuit activation and connectivity will be analyzed. • Task duration: 10 minutes per session, following the contextual manipulation (provocation vs. non-provocation). 3. Endocrine influences on threat processing: • Saliva samples will be collected at four time points: • Baseline (before T manipulation). • Post-T suppression/elevation (before gel application, if applicable). • Before experimental tasks (4-5 PM, after 50 minutes of T absorption). • Post-experiment (immediately after MRI). • Hormonal data (T, cortisol, oxytocin, estradiol, progesterone) will be analyzed for their association with neural and behavioral responses. | — |
Countries
Germany
Contacts
Public ContactUte;Nick Habel;Worm
Uniklinik RWTH Aachen;Uniklinik RWTH Aachen
Outcome results
None listed