A fundamental aspect of daily life decision-making involves the evaluation of costs and benefits. Neural systems underlying cost-benefit evaluation have been extensively examined, but the specific role of different neurotransmitters remains unclear. Numerous studies suggest that both dopamine (DA) and norepinephrine (NE) are closely related to reinforcement learning, guided exploration/exploitation, and behavioural energisation, although no studies to date have investigated the distinct role of DA and NE on cost-benefit decision-making and learning in human subjects.

Inclusion Criteria:

• Willingness to sign an informed consent
• Age between 18 and 35
• Body-Mass Index (BMI) between 17.5-30
• Availability for participation through the duration of the study

Exclusion Criteria:

• Diagnosis of a psychiatric or neurological disorder, including substance abuse or dependence (yes/no self-report - lifetime)
• Use of any psychopharmacological treatment 3 weeks before the test day (yes/no self-report)
• Use of any blood pressure medication (yes/no self-report - lifetime)
• Pregnancy (confirmed via urine pregnancy test) or nursing (yes/no self-report) or have plans to get pregnant in the near future (yes/no self-report) (females only)
• Diagnosis of a cardiac disease (medical questionnaire), obstructive respiratory disease (medical questionnaire), abnormal blood pressure (diastolic< 60mmHg; systolic< 90mmHg) (medical screening)
• Chronic renal failure (medical questionnaire)
• Hypothyroidism (medical questionnaire)
• Diabetes (medical questionnaire)
• Hypersensitivity to phenothiazines (medical questionnaire)
• Diagnosis of a cardiac disease (medical questionnaire)
• Alcohol consumption in the 24 hours before the test session starts (yes/no self-report)
• Food intake less than 3 hours before the test day (yes/no self-report)

double-blind (randomised) between-subjects design