Neural Account of Social Placebo Effect

Control Group Clinical Trial

Official title:

Neural Account of Social Placebo Effect

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03891459
• Other study ID #: FSPE
• Status: Completed
• Phase: N/A
• Start date: June 27, 2018
• Est. completion date: November 5, 2018

Study information

• Verified date: March 2019
• Source: Beijing Normal University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The current study aimed to reveal the neural mechanism of social placebo belief formation and belief representation, and also investigated how the brain pattern predict the social behavior performance under placebo manipulation.

Description:

Participants were randomly assigned to spray+ group (sprayed with saline but told as "oxytocin") and control group (sprayed with saline but told as "saline"). After 10 min, participants were invited to the resting-state, text viewing task in fMRI scanner.

In resting state session, participants with their eyes open and were instructed to attend to a black fixation cross centrally presented on a grey projection screen for 8 min (240TR).

The Text viewing task employed a mixed block and even-related fMRI design. Participants were asked to judge whether they could understand the stimuli or not by a button press (1=understand; 2=not understand). Three kinds of stimuli were presented in separate block including "oxytocin-function", "oxytocin-knowledge", "robot" related stimuli, each category contained 20 sentences. In each block, the sentence (within one category) was presented pseudo-randomized from 5s to 9s (with mean duration of 7s), then followed by a jittered time interval (interval time = sentence duration - response time; if participants made response within 5s, the sentence would not disappear until its duration reached 5s). There were two sessions with six blocks per session, and there were 5 sentences (trials) per block. The order of blocks and sentences were designed to present in pseudo-random order and were applied to all participants.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 68
• Est. completion date: November 5, 2018
• Est. primary completion date: November 2, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 35 Years

Eligibility

Inclusion Criteria:

• All participants had normal or corrected-to-normal vision, and mental healthy.

Exclusion Criteria:

• Participants who reported no history of neurological, endocrine or psychiatric disorders, who majored in psychology in college or recently participated in any other drug study were not recruited.

Related Conditions & MeSH terms

• Control Group
• Spray+ Group

Intervention

Behavioral:
• spray+ manipulation
Participants in spray+ group received placebo manipulation and were told they sprayed was oxytocin (in fact, it was saline);
• control manipulation
Participants in control group were told they sprayed saline (in fact, it was saline).

Locations

Country	Name	City	State
China	Beijing Normal University	Beijing	Beijing

Sponsors (1)

Lead Sponsor	Collaborator
Beijing Normal University

Country where clinical trial is conducted

China, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	The brain functional connectivity	For functional connectivity estimation, we adopted DLPFC, mPFC and reward related brain regions as the seeds to do whole-brain connectivity analysis. And the conducted two-sample T test to examine whether there would be some differences between spray+ and control groups.	8 mins, 240 TR in scanner
Primary	Social brain network properties in resting-state	For the network properties, we chose the social brain network as our target and interested network, then estimated the global efficiency within this network.And the conducted two-sample T test to examine whether there would be some differences between spray+ and control groups.	8 mins, 240 TR in scanner
Primary	The brain response pattern for the key concepts about oxytocin	We estimated the beta response trial by trial for each single concept and then investigated the neural representation of all concepts by using representational similarity analysis (RSA).	5.33mins, 160TR in scanner