Healthy Adult Participants
Conditions
Keywords
oxytocin, fMRI, fairness perception, prosocial behavior
Brief summary
This study aims to investigate the modulation of intranasally administered oxytocin (24 IU) on human fairness perception and related prosocial behaviors.
Detailed description
Fairness preference is a cornerstone of human sociality, often driving individuals to incur personal costs in order to uphold fairness norms. Oxytocin (OT), a neuropeptide, is considered a potential modulator of prosocial behavior, yet its specific mechanism of action in fairness decision-making remains unclear. Previous research has predominantly focused on the overall effects of OT on behaviors, without differentiating its roles across distinct processing stages such as cognitive evaluation and emotional anticipation. Furthermore, there is a lack of systematic investigation into whether its effects are modulated by social context and gain-loss contexts. Using a randomized, double-blind, placebo-controlled between-subjects design, the present study combines functional magnetic resonance imaging (fMRI) with the Dictator Game (DG) and the Ultimatum Game (UG) to elucidate how intranasal OT influences fairness perception and related prosocial behavior. The UG additionally involves strategic considerations of the proposer arising from the recipient's ability to reject the offer. Participants, act as proposers, are instructed to rate their perceived levels of fairness and guilt when receiving advantageous inequity and fair allocations in both gain and loss contexts. Following ratings, participants make decisions of accepting or rejecting the current allocation. Their brain activity and behavioral responses will be synchronously recorded during the tasks, and scores of questionnaires including Positive and Negative Affect Schedule, State-Trait Anxiety Inventory, Sensitivity to Punishment and Sensitivity to Reward Questionnaire, Social Value Orientation, Self-Report Altruism Scale, Prosocial Tendencies Measure, Behavioral Inhibition System and Behavioral Activation System Scale, Interpersonal Reactivity Index, Toronto Alexithymia Scale, Beck Depression Inventory-Ⅱ, Guilt and Shame Proneness Scale, Test of Self-Conscious Affect are also collected before the experiment.
Interventions
DRUGOxytocin nasal spray
intranasal administration of oxytocin (24IU)
DRUGPlacebo
intranasal administration of placebo (24IU)
Sponsors
University of Electronic Science and Technology of China
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy subjects without past or current psychiatric or neurological disorders.
Exclusion criteria
* History of head injury; pregnant, menstruating, taking oral contraceptives; medical or psychiatric illness. * The presence of metal in the body or claustrophobia.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Fairness rating scores | 1 hour | Participants are asked to rate their perceived levels of fairness on a 9-point Likert scale (1 = highly fair, 9 = highly unfair) to the computer's allocation in each trial. |
| Anticipated guilt rating scores | 1 hour | Participants are asked to rate the anticipated guilt they would feel if they accepted the allocation given by the computer in each trial. Ratings were conducted on a 9-point Likert scale (1 = not at all, 9 = highly guilty). |
| The binary decision to the initial allocation | 1 hour | Participants are asked to makde decisions of accepting or rejecting the allocation provided by the computer in each trial. |
| Brain activity patterns | 1 hour | Brain activity patterns in response to the outcome of the allocation given by computer and the binary decision. We will examine these brain response patterns via both the conventional univariate analysis and the machine learning-based multivariate pattern analysis (MVPA) approaches. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Inequity aversion parameters derived from the Fehr-Schmidt model | 1 hour | Inequity aversion parameters derived from the Fehr-Schmidt model are used to elucidate whether OT would modulate inequity aversion. This model-based analysis was conducted based on choices using hierarchical Bayesian modeling. In the Fehr-Schmidt model, the subjective value of a given allocationis determined by one's own and the other's allocation using the following formula: SV(Mself, Mother) = Mself - βmax{ Mself - Mother, 0}, Mself ≠ Mother where Mself is one's payoff and Mother is the other's payoff. Parameter β represents the weight assigned to inequity. Higher parameter values indicate a stronger degree of inequity aversion in participants. |
Countries
China
Contacts
CONTACTShuxia Yao, Dr
PRINCIPAL_INVESTIGATORShuxia Yao, Dr
University of Electronic Science and Technology of China
Outcome results
None listed