Investigating Neural Processing of Social Stimuli

Study Overview
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Brief Summary
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The primary goal of the present study is to test whether neural activity in brain regions associated with processing threat and social stimuli may underlie paranoid thinking.

Detailed Description
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Paranoia is a prominent symptom of psychosis that occurs in several other diagnoses, as well as the general population, and that is associated with significant distress and impairment. Previous research suggests that increased baseline activity of the amygdala and related neural circuits may serve as a mechanism for paranoid ideation. This exploratory study will use a paranoia induction procedure in healthy individuals who vary in pre-existing levels of paranoid ideation to test whether increases in self-reported paranoia are accompanied by increases in resting cerebral blood flow (CBF), decreased stimulus-driven neural activity in social processing networks, and increased behavioral perceptions of untrustworthiness. Participants will be randomly assigned to participate in a paranoia induction procedure or a control condition and will then complete neuroimaging and behavioral assessments.

Official Title
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Investigating Neural Processing of Social Stimuli: Investigating a Neurobehavioral Mechanism of Paranoia

Conditions
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Healthy Adults

Intervention / Treatment
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* Behavioral: Paranoia Induction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: between the ages of 18 and 55 Exclusion Criteria: current psychiatric diagnosis current use of psychotropic medications history of head trauma with loss of consciousness for more than 15 minutes presence of neurological or neurodegenerative disorder sensory impairments that preclude assessment presence of intellectual disability contraindications for MRI (e.g., metallic implants or pregnancy)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Paranoia Induction<br>Behavioral procedure involving social exclusion and negative feedback to induce paranoia | Behavioral: Paranoia Induction<br>* Behavioral procedure involving social exclusion and negative feedback to induce paranoia<br>|
| No Intervention: Control Condition<br>No manipulation of paranoid ideation | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Resting cerebral blood flow (CBF) | CBF in amygdala and related neural circuits | CBF measurements will be obtained during the study visit and will last approximately 9 minutes. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amount of Neural Activity | Task-related activation of amygdala and related neural circuits measured with blood-oxygenation-level-dependent imaging | Measurements will be obtained during the study visit and will last approximately 25 minutes. | 
| Ratings of Trustworthiness | Behavioral perceptions of the trustworthiness of others | Data will be obtained during the study visit and will last approximately 12 minutes. | 
| Self-reported paranoid ideation |  | Data will be obtained during the study visit and will last approximately 5 minutes. |