Stress & Self-Control Costs

Study Overview
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Brief Summary
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Self-control failures are a universal challenge for healthy and clinical populations. Recent work suggests these failures may arise from excessive cognitive costs associated with exercising self-control, yet the mechanisms underlying these costs are unknown. To address this, the investigators will use a validated decision-making task that measures how much individuals will pay (from a study endowment) to restrict access to tempting rewards that may lead to self-control failures. The investigators will examine these costs to identify their cognitive, neural and affective mechanisms. First, the investigators will identify the cognitive and computational mechanism that gives rise to self-control costs. Second, the investigators will characterize the neural correlates of self-control costs and identify neural mediators and connectivity patterns stemming from these costs. Finally, the investigators will examine how different classes of stressors (physical, social, or lifetime stress) shape the behavioral and neural representations of self-control costs.

Official Title
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Neural and Affective Mechanisms Underlying Prospective Self-control Costs

Conditions
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Self-Control

Intervention / Treatment
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* Behavioral: Cold-Pressor Task (CPT)
* Behavioral: Trier Social Stress Test (TSST)
* Behavioral: Modified Non-Stress CPT
* Behavioral: Modified Non-Stress TSST
* Device: Functional Magnetic Resonance Imaging (fMRI)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-70 years of age, able to speak, read, and write fluently in English be willing and able to follow study procedures and provide informed consent. Must additionally confirm they are on a diet to maintain/lose weight and are implementing/maintaining dietary changes. Exclusion Criteria: History of or medication for neurologic or psychiatric disease High-blood pressure or heart condition Diabetes, food allergies, metabolic disorders or history of eating disorder Use of corticosteroids or beta-blockers Metallic implants or devices contraindicating magnetic resonance imaging. Pregnancy is considered an exclusion criteria due to all stress and scanning procedures, thus pregnant participants will not be permitted to participate in the study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Physiological Stress<br>Healthy dieters will undergo a single-visit neuroimaging study where they will first complete demographic and self-report measures followed by a self-control decision task in an fMRI scanner. Prior to scanning, participants will be assigned to a physiological stress group and complete the corresponding stress task. For the physiological stress group, this task is the Cold-Pressor Task (CPT), a physiological stress task in which participants continuously submerge their hand and forearm in ice-water (0-4°C) for 3 minutes. After the scan, participants will wait for 1 hour in an adjacent study room where they will play out one trial of the decision-making task completed in the scanner. | Behavioral: Cold-Pressor Task (CPT)<br>* CPT is a physiological stress task in which participants continuously submerge their hand and forearm in ice-water (0-4°C) for 3 minutes.<br>Device: Functional Magnetic Resonance Imaging (fMRI)<br>* Participants will complete the self-control task in the fMRI scanner.<br>|
| Experimental: Social Stress<br>Healthy dieters will undergo a single-visit neuroimaging study where they will first complete demographic and self-report measures followed by a self-control decision task in an fMRI scanner. Prior to scanning, participants will be assigned to the social stress group and complete the corresponding stress task. For the social stress group, this task is the Trier Social Stress Test (TSST), a psychosocial stressor that requires participants perform a short speech and solve math problems in front of 2 evaluative judges. After the scan, participants will wait for 1 hour in an adjacent study room where they will play out one trial of the decision-making task completed in the scanner. | Behavioral: Trier Social Stress Test (TSST)<br>* The TSST is a psychosocial stressor that requires participants perform a short speech and solve math problems in front of 2 evaluative judges.<br>Device: Functional Magnetic Resonance Imaging (fMRI)<br>* Participants will complete the self-control task in the fMRI scanner.<br>|
| Active Comparator: Physiological Non-Stress<br>Healthy dieters will undergo a single-visit neuroimaging study where they will first complete demographic and self-report measures followed by a self-control decision task in an fMRI scanner. Prior to scanning, participants will be assigned to the physiological non-stress group and complete the corresponding stress task. For the physiological non-stress group, participants will continuously submerge their hand and forearm in warm water for 3 minutes. After the scan, participants will wait for 1 hour in an adjacent study room where they will play out one trial of the decision-making task completed in the scanner. | Behavioral: Modified Non-Stress CPT<br>* The modified non-stress CPT involves participants continuously submerging their hand and forearm in warm water for 3 minutes.<br>Device: Functional Magnetic Resonance Imaging (fMRI)<br>* Participants will complete the self-control task in the fMRI scanner.<br>|
| Active Comparator: Social Non-Stress<br>Healthy dieters will undergo a single-visit neuroimaging study where they will first complete demographic and self-report measures followed by a self-control decision task in an fMRI scanner. Prior to scanning, participants will be assigned to the social stress group and complete the corresponding stress task. For the social non-stress group, participants will be asked to prepare for a speech that they will practice alone to themselves and complete math problems alone on a piece of scrap paper. After the scan, participants will wait for 1 hour in an adjacent study room where they will play out one trial of the decision-making task completed in the scanner. | Behavioral: Modified Non-Stress TSST<br>* For the modified non-stress TSST, participants are asked to prepare for a speech that they will practice alone to themselves and complete math problems alone on a piece of scrap paper.<br>Device: Functional Magnetic Resonance Imaging (fMRI)<br>* Participants will complete the self-control task in the fMRI scanner.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average Self-Control Cost | The self-control cost is the amount that a participant would be willing to pay to avoid temptation. This will be tested in a self-control task in which participants are shown an images of snack food and report how much they would be willing to avoid the different food items. | Day 1 | 
| Change in fMRI BOLD Signal During Self-Control Decisions | Functional MRI (fMRI) data will be analyzed to measure changes in blood-oxygen-level-dependent (BOLD) signal in the Dorsal Anterior Cingulate Cortex (dACC), Frontopolar Cortex (FPC) and Orbitofrontal Cortex (OFC) regions of interest as participants make self-control cost decisions during the self-control activity. | Day 1 (Up to 1.5 Hours) |