Scientists probe brain circuits to unlock the secrets of motivation

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Healthy volunteers aged between 18 and 40 years * Participants without confounding factors such as neural alterations related to neurological pathology, whether neurodegenerative (e.g., Alzheimer, Parkinson, Huntington, multiple sclerosis, amyotrophic lateral sclerosis), motor (e.g., dystonia, essential tremors, cerebellar syndrome), traumatic (e.g., traumatic brain injury, medulla lesion) or psychiatric pathologies, whether mood disorders (e.g., depression, bipolarity), anxious troubles (e.g., obsessional compulsive disorder, post-traumatic stress disorder), psychotic (e.g., schizophrenia, delusion), substance-related (e.g., alcool, drug or medicine addiction), food-related (e.g., anorexia, bulimia), neurodevelopmental (e.g., autism, attention-deficit with hyperactivity disorder) or personality (e.g., borderline personality disorder, antisocial personality disorder, obsessive-compulsive disorder). * Participants affiliated with a compulsory social security scheme. Exclusion Criteria: * Persons deprived of liberty by judicial or administrative decisions. * Pregnant women, women in labor or breastfeeding women * Persons admitted to a health or social institution for purposes other than research. * Adults under legal protection measures (e.g., guardianship or curatorship). * Participation in other interventional research with an ongoing non-inclusion period. * Neurological or psychiatric disorders. * Use of tricyclic antidepressants (amitriptyline, clomipramine, imipramine, nortriptyline), neuroleptics (chlorpromazine, haloperidol, risperidone, olanzapine, quetiapine), or recreational drugs within the past 48 hours. * Regular use of recreational drugs. * Sleep deprivation (\< 5 hours regularly over the last 3 months) * Left-handedness or ambidexterity. * Physical injuries impacting motor tasks. * Presence of metal implants in the head (excluding oral fillings). * Presence of implanted medical devices (e.g., pacemaker). * Presence of metallic injuries in the eyes. * Claustrophobia. * Piercings incompatible with MRI procedures. * Contraindication to MRI * Persons who refused to be informed of eventual medical anomalies discovered by the MRI * Personal or family history (first-degree relatives) of epilepsy or seizures. Severe and/or frequent headaches (only for participants receiving transcranial magnetic stimulation, e.g preparatory experience 1 and experience 1) * Baldness impeding electrode placement (only for participants receiving transcranial electrical stimulation and EEG measurements, e.g experiments 2, 3 and 4) * Facial or ear pain and/or recent ear trauma (only for participants receiving transcutaneous vagal nerve stimulation, e.g experiment 5)