Effects of Intranasal Oxytocin and Stress on Belief Updating
Condition: Healthy
Study type: Interventional

Summary: 
      To investigate the effect of 24IU intranasal oxytocin on belief updating when people in
      stress or non-stress condition.
    

Detailed description: 
      In a randomized, double-blind, placebo controlled between-subjects design, healthy male
      volunteers receive intranasal oxytocin or placebo under stress or non-stress group prior
      belief updating task.

      The Trier Social Stress Test (TSST) was used to induce psychosocial stress - this
      standardized technique enables a naturalistic exposure to a psychosocially stressful
      situation. This method consists primarily of a public speaking in second language (English)
      and a mental arithmetic task performed in front of a panel. Participants were not informed of
      the tasks prior to their recruitment. At the start of the TSST, they were told to prepare a
      5-min speech to an unknown panel on personal suitability for their ideal job; the job
      description was matched to each participant, taking into consideration his personal
      aspirations. After the instructions, subjects were given 10 minutes of solitary preparation
      for this task. Then, they entered the TSST room and were told to start the presentation in
      front of a panel of two formally-dressed judges (one male and one female) and a conspicuous
      video camera. Any pause during the speech prompted a reminder from the judges of the
      remaining time. The interview was followed by 5 minutes of mental arithmetic performed out
      loud. Subjects were instructed to serially subtract 13 from 1022 as quickly and accurately as
      possible in front of the panel. If a mistake was made, the subject was told to start over
      from the beginning. After the mental arithmetic task, the TSST was concluded - subjects were
      confronted with the psychosocially stressful situation for a total of 10 minutes.

      Non-stress groups first underwent a 5-minute session of travel magazine reading with two
      casually-dressed people (one male and one female), then did as many easy arithmetic questions
      within 5 minutes on paper. Participants were told that none of their answers would be marked.

      All participants completed two sessions of self life event estimations, each with the same
      set of 40 adverse life events. The subjects were first presented with the events, then were
      instructed to estimate their likelihood (0-99%) of experiencing each event in the future
      (first Estimate, E1) and rate their confidence in their estimate. They were then presented
      with the actual probability of each event occurring to an average person in a similar
      environment (Feedback, F) and asked to rate their acceptance of the presented feedback. Five
      minutes after the first session, participants were instructed to perform the same task and
      provide their second estimate (E2) for the same 40 events in a randomized order and were,
      again, instructed to rate their confidence in their estimate. This time, however, no feedback
      was given. This process was repeated for a friend life event estimation session. After the
      second session, participants were given a surprise memory test for the presented feedback.
    

Intervention name(s): Oxytocin; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): intranasally administrated; intranasally administrated
Other intervention name(s): Saline
Intervention MeSH terms: Oxytocin
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: The study utilized a randomized, double-blind, PBO controlled, between-subject design.
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: intranasal oxytocin; stress; belief updating