Testing the Efficacy of an Eye-tracking-based Treatment in Reducing Stress-related Symptoms in Veterans with PTSD

The study will examine the efficacy of a feedback-based treatment applying eye-tracking (Gaze-Contingent Music Reward Therapy) to change attention and gaze patterns associated with angry faces relative to a response-time-based attention bias modification treatment applying the dot-probe task and a control group.

The study will recruit veterans with posttraumatic stress disorder (PTSD) due to a trauma acquired during military service. A compatibility check and initial filtering will happen via phone call, using basic symptom questionnaires for self-report and initial examination of exclusion criteria.

This study has four phases:

1. Clinical Assessment - Participants who pass the initial filtering and express a desire to participate in the study will be invited to a structured clinical interview during which clinical and practical inclusion and exclusion criteria will be examined by an independent evaluator (a clinical psychologist). After an explanation about the study and provision of signed informed consent from the participant, the clinical interview (CAPS-5 and MINI) will be conducted and self-report questionnaires will be completed:

   * Post-trauma Checklist (PCL) - PTSD symptoms
   * Patient Health Questionnaire (PHQ) - Depression Symptoms
   * Attention Bias Questionnaire (ABQ) - Attention Patterns
   * Attention Control Scale (ACS) - Attention Control
2. Attention bias measurement - participants will perform computerized tasks aimed to measure their attention bias prior to treatment.

   * Free viewing of 30 matrices each with 16 faces (8 with neutral facial expression and 8 with angry facial expression) while monitoring gaze location with passive eye-tracking technology - duration of this assessment is about 15 minutes.
   * Attention bias measurement using a dot-probe task in which two faces are presented on the screen and replaced by an arrow pointing right or left, and the participant has to indicate the arrow's direction by pressing a key - duration of the task is about 5 minutes.
   * Generic Flanker attention task, in which a middle arrow is presented with additional arrows to the right and left (for example \<\<\>\<\< or \>\>\>\>\>) and the participant is asked to identify the direction of the middle arrow by pressing a key - duration of the task is about 5 minutes.
3. Attention Training - Next participants will be randomly assigned to one of three groups.

   * 8 sessions of Gaze Contingent Music Reward Therapy (GC-MRT) - In every session, the participant chooses music to which to listen and is then asked to view matrices of 16 faces as described above. The music plays when the participant views neutral faces and stops when viewing angry faces - each meeting lasts about 20 minutes.
   * 8 sessions of Attention Bias Modification Treatment based on a dot-probe task described above with one difference: While in the assessment task the probe location is counterbalanced at neutral and angry faces locations, in the treatment task the arrow always appears at the neutral face location - each session takes about 20 minutes.
   * Control group in which participants are exposed to the same procedure as GC-MRT but the music will play continually without contingency to participant's gaze.
4. Post-Training Assessment and Measurements - After the 8 treatment sessions, participants will undergo another clinical interview and the same questionnaires and attention assessment tasks similar to those conducted before the treatment. The clinical interview, questionnaires, and attention measurements will occur again after three months from the end of treatment (follow-up).

   * NOTE: As a direct result of the ongoing war in Israel the study has encountered serious difficulties in veteran-patients recruitment. First, many veterans were called into active duty since October 7th, 2023, limiting their availability for treatment/research. Second, with the war, numerous new treatment options have become available for veterans with PTSD, making it extremely difficult to recruit patients into a trial.

To date (March 18, 2025), 113 (target n=150) veterans have enrolled in the study and started treatment. Blinded group sizes from stratified randomization thus far stand at 39, 38, and 36.

Given this situation, we are forced to terminate the study early on June 1st, 2025. We will enroll as many additional participants as possible until this end-date.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosis of PTSD according to the DSM-5 and related to military service, ages 20-70

Exclusion Criteria:

* Psychotic or Bipolar disorder, drug and alcohol abuse, high risk of harming self or others, other psychological treatment, vision problems that are not overcome with regular glasses, physical disability that prevents ability to operate computer.