Influence of Stress on Encoding and Prediction

Study Overview
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Brief Summary
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The purpose of this study is to investigate the neural mechanisms by which acute stress influences statistical learning and episodic encoding.

Detailed Description
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This study aims to assess the neural and behavioral mechanisms by which acute stress modulates episodic encoding (which involves the trisynaptic pathway: entorhinal cortex, dentate gyrus, cornu ammonis [CA] 3, and CA 1) and statistical learning (monosynaptic pathway: entorhinal cortex, CA1) in humans.

Official Title
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Neural Mechanisms of Stress Effects Across Hippocampal Encoding and Prediction

Conditions
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Stress, Learning, Spatial

Intervention / Treatment
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* Behavioral: Socially Evaluated Cold Pressor Test
* Behavioral: Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-45 years old Fluent in English BMI 18-35 Exclusion Criteria: Meeting current DSM-V criteria for any substance use disorder (except caffeine) Having current significant medical conditions or psychiatric symptoms requiring medication Current use of medications/drugs that interfere with physiological stress responses Peri and post-menopausal women, pregnant or lactating women, and those with hysterectomies Metal in body (for MRI safety) history will be assessed for female participants.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Acute Stress<br>Participants complete the socially evaluated cold pressor test (SECPT), a validated laboratory-based stress induction procedure involving submerging an arm in an ice bath | Behavioral: Socially Evaluated Cold Pressor Test<br>* The SECPT is a brief validated laboratory-based stress induction containing both physical and social elements<br>|
| Active Comparator: No Stress<br>Participants complete a matched condition with no stress-related exposure involving submerging an arm in warm water | Behavioral: Control<br>* This is matched to the SECPT but with warm instead of cold water<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in fMRI signal | fMRI signal during learning will be assessed using connectivity, multivariate, and univariate approaches over 1-2 hour long learning period | 1-2 hours | 
| Statistical learning | Online measures of statistical learning (reaction time) based on item predictability during task | 1-2 hours | 
| Retention of statistical learning | Offline measure of statistical learning assessed through familiarity tests the next day (comparison of accurate recognition of previously-studied pairs to chance, 50%) | 1 hour | 
| Episodic memory | Memory for individual items will be assessed through performance on old/new recognition tests the next day, quantified as hit rates and A' (non-parametric normalized ratio of hits to false alarms) | 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cortisol reactivity | Change in salivary cortisol levels following the SECPT/control procedure | 1-2 hours | 
| Alpha-amylase reactivity | Change in salivary alpha-amylase levels following the SECPT/control procedure | 1-2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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memory