Clinical Research Directory

Inclusion Criteria: * Healthy participants (defined as those without a pre-existing medical comorbidity). * Aged between 18-65 years. * Ability to understand and speak the Dutch language. * BMI between 18 and 25 kg/m2 Exclusion Criteria: * Medical history of chronic or severe diseases affecting the cardiovascular, respiratory, urogenital, gastrointestinal/hepatic, haematologic/immunologic, HEENT (head, ears, eyes, nose, throat), dermatological/connective tissue, musculoskeletal, metabolic/nutritional, endocrine, neurological/psychiatric systems. * A history of major abdominal surgery. * Gastrointestinal complaints. * Any use of medication, especially those affecting gastric motility and nausea, apart from oral contraceptives. * Current or lifetime psychopathology (including PHQ-9 and GAD-7 scores \> 10) * Substance abuse, including excessive alcohol consumption (\>20 alcoholic consumptions per week) and the use of recreational drugs. * Smoking. * Pregnancy, lactation, or intention to become pregnant during the study period * Use of devices (e.g., cochlear implants) or other conditions (e.g. wounds, permanent ear-piercing) complicating the use of the tVNS device. * Administration of investigational drugs or participation in any scientific intervention study that might interfere with this study (to be determined by the principal investigator) within 180 days preceding the commencement of the study. * Students and employees of Maastricht University are not precluded from participation, unless they have a direct personal, professional or hierarchical position with regards to any of the study team members or their department.