Altruistic Decisions

Not Applicable

Terminated

• Conditions: Healthy
• Interventions: Other: Behavior; Other: fMRI (functional Magnetic Resonance Imagery); Other: MEG (MagnetoEncephaloGraphy)

• Registration Number: NCT03116581
• Lead Sponsor: Hospices Civils de Lyon

Brief Summary

The study aimed to understand how payoffs for others influence perceptual decision making. The research consists in testing how varying monetary payoffs for another modify the perceptual decision making processes. The use of drift diffusion models on a random dots task enable the characterization of the decision parameter(s) that are modulated when a decision is made to win payoffs for others as compared to decisions for self-benefits. Once the parameter revealed through behavioral experiment, neuroimaging is applied to find the neural correlates of the effects of taking others into account in the decision making process.

Detailed Description

Not available

Study Timeline

• Study Start: 2014-02-03
• Primary Completion: 2016-07-22
• Study Completion: 2016-07-22
• Study First Submitted: 2017-03-07
• Study First Submitted QC: 2017-04-11
• Study First Posted: 2017-04-17
• Status Verified: 2017-11
• Last Update Submitted: 2017-11-24
• Last Update Posted: 2017-11-28

Recruitment & Eligibility

• Status: TERMINATED
• Sex: All
• Target Recruitment: 159

Inclusion Criteria

• Aged between 18 and 35
• Right-handed
• French
• Normal vision or corrected by contact lenses

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Exclusion Criteria

• Contraindications to the MEG examination
• Presence of a perceptual disorder (vision) or motor impairing the capacity to carry out the tasks requested (including dyschromatopsia and achromatopsia).
• Taking of medical treatment in progress (excluding contraceptive pill).
• Known neurological or psychiatric history or disorders.
• Participants in an exclusion period for any other research.
• Participants who do not benefit from social protection.
• Participants refusing to be informed of the results of the medical examination.
• Participants who refuse to be informed of the possible detection of an anomaly.
• Participants with MRI contraindications

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Audience effect	fMRI (functional Magnetic Resonance Imagery)	In order to clarify the complex changes in the decision-making processes induced by simple observation by others (audience) , the experiment have two levels of difficulty . These levels of difficulty will be determined in such a way as to achieve better 'public' performance than 'private' when the task is easy (high level of consistency) and poor performance when the task is difficult (low level of coherence) As described in the literature in psychology. Drift diffusion models will be used to better understand the variations in performance, to decipher between a modulation of the diffusion velocity and or of the decision threshold. This study will help characterize how observation by others modulates performance. Once the decision parameter characterized with behavioral experiment, the study aims to better understand the neural network sustaining the impact of observation by others on the decision making process.
Audience effect	Behavior	In order to clarify the complex changes in the decision-making processes induced by simple observation by others (audience) , the experiment have two levels of difficulty . These levels of difficulty will be determined in such a way as to achieve better 'public' performance than 'private' when the task is easy (high level of consistency) and poor performance when the task is difficult (low level of coherence) As described in the literature in psychology. Drift diffusion models will be used to better understand the variations in performance, to decipher between a modulation of the diffusion velocity and or of the decision threshold. This study will help characterize how observation by others modulates performance. Once the decision parameter characterized with behavioral experiment, the study aims to better understand the neural network sustaining the impact of observation by others on the decision making process.
Vicarious reward	Behavior	If a decision influences the well-being of another (through monetary payoff), the decision making processes should differ from a decision that would influences only oneself. The difference will be reflected in the reaction-times and in the accuracy of the response to the task. The drift diffusion models care then used to estimate le decision parameter in each condition and understand which parameter is influenced by the beneficiary of the payoff associated with a decision. Once the decision parameter characterized with behavioral experiment, the study aims to better understand the neural network sustaining the influence of others on the decision making process, by assessing the neural activity related to the decision making processes. Also, the research compares how the brain responses for payoff for others and payoffs for oneself, specially to confirm that these responses are located in different areas of the Anterior cingulate Cortex.
Vicarious reward	fMRI (functional Magnetic Resonance Imagery)	If a decision influences the well-being of another (through monetary payoff), the decision making processes should differ from a decision that would influences only oneself. The difference will be reflected in the reaction-times and in the accuracy of the response to the task. The drift diffusion models care then used to estimate le decision parameter in each condition and understand which parameter is influenced by the beneficiary of the payoff associated with a decision. Once the decision parameter characterized with behavioral experiment, the study aims to better understand the neural network sustaining the influence of others on the decision making process, by assessing the neural activity related to the decision making processes. Also, the research compares how the brain responses for payoff for others and payoffs for oneself, specially to confirm that these responses are located in different areas of the Anterior cingulate Cortex.
Vicarious reward	MEG (MagnetoEncephaloGraphy)	If a decision influences the well-being of another (through monetary payoff), the decision making processes should differ from a decision that would influences only oneself. The difference will be reflected in the reaction-times and in the accuracy of the response to the task. The drift diffusion models care then used to estimate le decision parameter in each condition and understand which parameter is influenced by the beneficiary of the payoff associated with a decision. Once the decision parameter characterized with behavioral experiment, the study aims to better understand the neural network sustaining the influence of others on the decision making process, by assessing the neural activity related to the decision making processes. Also, the research compares how the brain responses for payoff for others and payoffs for oneself, specially to confirm that these responses are located in different areas of the Anterior cingulate Cortex.
Audience effect	MEG (MagnetoEncephaloGraphy)	In order to clarify the complex changes in the decision-making processes induced by simple observation by others (audience) , the experiment have two levels of difficulty . These levels of difficulty will be determined in such a way as to achieve better 'public' performance than 'private' when the task is easy (high level of consistency) and poor performance when the task is difficult (low level of coherence) As described in the literature in psychology. Drift diffusion models will be used to better understand the variations in performance, to decipher between a modulation of the diffusion velocity and or of the decision threshold. This study will help characterize how observation by others modulates performance. Once the decision parameter characterized with behavioral experiment, the study aims to better understand the neural network sustaining the impact of observation by others on the decision making process.

Primary Outcome Measures

Name	Time	Method
Modulation of the decisional parameter by the payoff conditions	1 hour	behavioral data (reaction-times and accuracy) are collected and the decision parameter can be estimated from them using Drift Diffusion Models
Modulation of the decisional parameter by the beneficiary conditions	1 hour	behavioral data (reaction-times and accuracy) are collected and the decision parameter can be estimated from them using Drift Diffusion Models

Secondary Outcome Measures

Name	Time	Method
Time-frequency brain responses	1 hour	study of the oscillatory activity elicited in the brain
BOLD	1 hour	Variation of the blood-oxygen-level dependent (BOLD) signal
Event-Related potentials	1 hour	study of the time-locked brain activity

Trial Locations

Locations (1)

CH le Vinatier; 🇫🇷 Bron, France