Effects of Methylphenidate, Modafinil, and MDMA on Emotion-processing in Humans: A Pharmaco-fMRI Study

Inclusion Criteria: * Age between 18 and 45 years * Sufficient understanding of the German language * Subjects understand the procedures and the risks associated with the study * Participants must be willing to adhere to the protocol and sign the consent form * Participants must be willing to refrain from taking illicit psychoactive substances including cannabis during the study * Participants must be willing to drink only alcohol-free liquids and no xanthine-containing liquids (such as coffee, black or green tea, red bull, chocolate) after midnight of the evening before the study session, as well as during the study day * Participants must be willing not to drive a traffic vehicle within 24h following MDMA administration * Women of childbearing potential must have a negative pregnancy test at the beginning of the study and must agree to use an effective form of birth control. Pregnancy tests are repeated before each study session. * Body mass index: 18-27kg/m2 Exclusion Criteria: * Chronic or acute medical condition including clinically relevant abnormality in physical exam, laboratory values, or ECG. In particular: Hypertension (\>140/90mmgHg) or Hypotension (SBP\<85mmHg). Personal or first-grade history of seizures. Cardiac or neurological disorder. This also includes contraindications for MRI scanning (any type of implants such as heart pacer, insulin-pump, cochlea-implants, heart valve) * Current or previous psychotic or major affective disorder * Psychotic or major affective disorder in first-degree relatives * Prior illicit drug use (except tetrahydrocannabinol (THC)-containing products) more than 5 times or any time within the previous 2 months * Pregnant or nursing women * Participation in another clinical trial (currently or within the last 30days) * Use of medications that are contraindicated or otherwise interfere with the effects of the study medications (monoamine oxidase inhibitors, antidepressants, sedatives etc. ) * Tobacco smoking (regularly \> 10cigarettes / day)