The main aim of the present study is to investigate the effects of orally administered Losartan on bottom-up and top-down attentional control to socio-emotional stimuli by combining a validated saccade/antisaccade eye-tracking paradigm with a randomized between-subject placebo-controlled pharmacological trial design.

Animal models and initial findings in humans suggest that the angiotensin II antagonist Losartan may have neuroprotective effects and could potentially enhance cognitive functions, including valence-specific attention and regulatory control. Within this context the present study aims to examine whether angiotensin II blockade via Losartan modulates top-down and bottom-up attentional control towards socio-affective stimuli. To this end, healthy individuals will undergo a double-blind, between-subjects, placebo-controlled pharmaco-eye-tracking experiment and receive a single oral dose of Losartan (50 mg) or placebo before performing a saccade/anti-saccade task 90 minutes after administration. The task paradigm will encompass social (happy, angry, fearful, sad and neutral faces) and non-social (oval) stimuli to examine general as well as social and emotion-specific effects of oral losartan.

Inclusion Criteria:

Healthy subjects who volunteer to participate and are able to fully understand and agree with this study by written informed consent.

Normal or corrected-normal version

Exclusion Criteria:

• History of neuropsychiatric diseases.
• History of cardiac disease, including arrhythmias, aortic stenosis, or congestive heart failure; history of syncope or unexplained loss of consciousness.
• History of hepatic diseases, including cholestasis, biliary obstructive disease, or severe liver dysfunction.
• History of renal diseases, including renal stones or renal failure.
• History of hyponatremia(Serum sodium <135mmol/L) or hyperkalemia (Serum potassium>5.5mmol/L); history of diabetes mellitus or diabetes insipidus
• Known hypersensitivity or allergic reaction to any medication or hormone; strong allergic reaction to food.
• Infections such as COVID-19 or influenza, or unexplained fever.
• Subjects with hypertension (BP ≥130/80mmHg) or hypotension (BP ≤ 90/60mmHg).
• History of alcohol or drug abuse; smoker (≥ 10 cigarettes or ≥ 3 cigars or ≥ 3 pipes/day); smoker using e-cigarettes.
• Blood donation (≤ 1 month prior to administration).
• Take oral contraceptives or receive hormonal medications in the three months prior to the experiment.
• Pregnant or breastfeeding.