The Effects of Intranasal and Oral Administration of Oxytocin on Responses to Emotional Scenes

Differential Modulation of Neural and Behavioral Responses to Emotional Scenes by Intranasal and Oral Oxytocin Administration in Healthy Men

The study will investigate whether oxytocin administered either intranasally or orally (lingual) (24 international units, IU) can differentially modulate men's neural and behavioral responses to emotional scenes using an implicit emotional paradigm.

Previous studies have reported that oxytocin administration intranasally and orally (spray on the tongue) can modulate neural and behavioral responses during processing of face emotions and can influence top-down attention to social stimuli. However, no research has directly compared the neural and behavioral effects of the two different administration routes on the processing of emotional scenes. In the current randomized, double-blind, between-subjects, placebo-controlled study, 160 healthy male subjects will be recruited and receive treatment either oxytocin (24IU, orally/intranasally) or placebo (orally/intranasally). Prior to treatment, all subjects will complete a number of questionnaires to control for potential group differences in potential confounders in terms of personality traits and mood, including: Beck Depression Inventory-II (BDI), Autism Spectrum Quotient (ASQ), Liebowitz Social Anxiety Scale (LSAS), State-Trait Anxiety Inventory (STAI), Childhood Trauma Questionnaire (CTQ), Interpersonal Reactivity Index (IRI). Additionally, the Positive and Negative Affect Schedule (PANAS) is administered before the treatment and before and after completing the implicit emotional scanning task to measure any changes in mood. Forty-five minutes after receiving treatment, subjects will be required to undergo and MRI scanning session including structural scans and resting-state fMRI followed by an implicit emotional scene processing task (picture source: Nencki affective picture system, including positive, neutral, and negative-valence social and non-social scenes). After fMRI scanning, subjects will be required to rate emotional stimuli presented during the scan on valence, intensity, and arousal using 1-9 point Self-Assessment Manikin (SAM) scales.

Inclusion Criteria:

• Healthy subjects without any past or present psychiatric or neurological disorders

Exclusion Criteria:

• 1. History of brain injury 2. Head trauma 3. Substance abuse 4. Medication