Altruistic Decisions

Civil Hospices of Lyon

Status: Terminated

Conditions: Healthy

Treatments: Other: Behavior; Other: MEG (MagnetoEncephaloGraphy); Other: fMRI (functional Magnetic Resonance Imagery)

Study type: Interventional

Funder types: Other

Identifiers

NCT03116581

69HCL16_0680

Details and patient eligibility

About

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.

Enrollment: 159 patients

Sex: All

Ages: 18 to 35 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

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

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

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

---

159 participants in 2 patient groups

Vicarious reward

Other group

Description:

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.

Treatment:

Other: Behavior

Other: MEG (MagnetoEncephaloGraphy)

Other: fMRI (functional Magnetic Resonance Imagery)

Audience effect

Other group

Description:

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.

Treatment:

Other: Behavior

Other: MEG (MagnetoEncephaloGraphy)

Other: fMRI (functional Magnetic Resonance Imagery)