Biological Basis of Individual Variation in Social Cooperation
Condition: Healthy
Study type: Interventional

Summary: 
      The project has three overall objectives. The first is to determine whether and how
      administration of intranasal oxytocin (OT) and intranasal vasopressin (AVP) influence
      cooperative decision-making and neural responses to cooperative and un-cooperative social
      interactions. The second is to determine whether and how intranasal vasopressin influences
      subjective evaluations of and neural responses to same and opposite-sex face stimuli and to
      determine if any of these effects persist beyond the period of AVP exposure. The third
      objective is to determine if intranasal OT influences empathy-related behavior and associated
      brain activity.
    

Detailed description: 
      There are several objective to the study.

      Objective 1: In this double-blind, placebo-controlled, pharmaco- fMRI study, men and women
      will be randomized to treatment with either 24 IU intranasal OT, 20 IU intranasal AVP, or
      placebo (PL). Approximately 40 minutes later, brain function will be imaged with fMRI as
      participants play an iterated Prisoner's Dilemma game with same-sex partners. The resulting
      data will be analyzed to investigate OT and AVP effects on cooperative behavior and the
      neural response to cooperative social interactions.

      In addition to this cross-sectional design, a subset of participants will return on a second
      day for a within-subject study.

      Objective 2: Men and healthy women will be randomized to treatment with either 40 IU
      intranasal AVP or a saline placebo approximately 30 minutes before their brain function is
      measured with fMRI as they view same and other-sex faces. All subjects will be scanned a
      second time several days later with no treatment to evaluate the persistence of AVP effects
      over time. The resulting data will be analyzed to investigate AVP effects on subjective
      evaluations and neural responses to viewing same and opposite sex faces.

      Objective 3: Healthy men and healthy women will receive either 24IU intranasal OT or PL
      approximately 40 minutes before their brain function is measured with fMRI as they view
      animations of geometric shapes depicting either random movement or social interactions such
      as playing, chasing, fighting. All participants will receive PL on scan 1 and will be
      randomized to either 24IU intranasal OT or PL on scan 2. The resulting data will be analyzed
      to investigate OT effects on subjective evaluations and neural responses to the animations.
    

Intervention name(s): Intranasal Oxytocin (OT) 24 IU; Intranasal Vasopressin (AVP); Intranasal Placebo; Intranasal Vasopressin (AVP) 40 IU; Lorazepam
Intervention type(s): Drug; Drug; Drug; Drug; Drug
Intervention description(s): Participants will self-administer a single dose of 24 international units (IU) oxytocin. Five puffs per nostril, each with 2.4 IU oxytocin. Ten puffs total.; Participants will self-administer a 1 ml solution containing 20 units of AVP. Five puffs per nostril, each with 2 International Units (IU) AVP. Ten puffs total).; Participants will receive placebo sprays that are pH adjusted to comparable levels of the drugs given. Five puffs per nostril; ten puffs total.; Participants will self-administer a 0.5 ml solution containing 40 international units (IU) of AVP. 5 puffs in total, each with 4 International Units (IU) AVP.; Subjects will take 1.0 mg of lorazepam orally 60 minutes prior to fMRI scan.
Other intervention name(s): Oxytocin: Syntocinon Nasal Spray
Intervention MeSH terms: Vasopressins; Arginine Vasopressin; Lorazepam; Oxytocin
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Basic Science
Keywords: Social cooperation; Oxytocin; Vasopressin; Prisoner's Dilemma game; Empathy; fMRI