Fear and Avoidance in PTSD Patients

Summary

The purpose of this research study is to study how the brain learns to avoid certain stimuli or situations using an experimental paradigm. The big goal is to measure brain responses and subject's feelings and expectations when they are learning to actively avoid experimental stimuli, and how fear extinction learning and monetary cost can change how and when subjects are to avoid.

Conditions

• Post Traumatic Stress Disorder

Interventions

BEHAVIORAL

Fear Conditioning

Participants will be administered increasing intensities of mild electric shock via electrodes connected to the foot. New Biopac stimulators that can deliver higher shock intensity, provided participants agreement will be used to assure adequate conditioning levels. Stimulation is measures in milliamps (mA), and each delivered stimulation will be 0.5 seconds long (500 milliseconds). To colored (blue, red, \& yellow) light stimuli (CS). The light stimulus is followed by a shock or no shock depending on color.

OTHER

Avoidance conditioning

Via button pressing. Only one stimulus-CS will enable control over experiencing the shock: the participant can press the button during the first 2 seconds of the light presentation to avoid the shock.

OTHER

Pavlovian fear extinction learning

After avoidance conditioning, the CS+ associated with avoidance responding appears with no button to press and no shock is administered.

OTHER

Willingness to pay to avoid shock

On the next day, participants receive a monetary stipend to use to pay to guarantee that they are not to receive any shocks if they press a button from the CS+. This and all previously described experimental phases noted above will occur inside of the fMRI scanner.

Sponsors & Collaborators

• National Institute of Mental Health (NIMH)

  collaborator NIH

• The University of Texas Health Science Center, Houston

  lead OTHER

Principal Investigators

• Mohammed Milad, PhD · The University of Texas Health Science Center at Houston (UTHealth Houston)

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2021-09-09

Primary Completion

2028-01-31

Completion

2028-01-31

Countries

• United States

Study Locations