Increasing Psychological Resilience in Combat Soldiers Applying Advanced Eye-Tracking-Based Attention Bias Modification

Study Overview
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Brief Summary
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Military service in combat units entails exposure to traumatic events that require mental adjustment. To develop and efficiently apply attention bias modification interventions aimed at enhancing soldiers' mental resilience, it is essential to test the efficiency of such training programs in RCTs. The purpose of the current study is to examine the efficiency of a new attention eye-tracking-based training protocol, in comparison to an RT-based training protocol, and to a control group, in reducing risk for post-trauma symptoms in combat deployed soldiers.

Detailed Description
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Following the explanation to participants regarding the study process, those who give written consent to participate will be randomly placed into one of three groups: GCFT (N=180), ABMT (N=180), and a neutral control group - RT-based task (N=180). The study will include 3 measurement points: before attention training (in basic training before deployment), after attention training (in basic training camp, still before deployment), and after a combat deployment cycle (6-12 months - to be determined based on the military deployment mission of the participants). In each measurement point, the participants will complete computerized tasks to measure attention and will complete self-report questionnaires.

Official Title
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Increasing Psychological Resilience in Combat Soldiers Applying Advanced Eye-Tracking-Based Attention Bias Modification

Conditions
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PTSD, Depression, Anxiety Disorders

Intervention / Treatment
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* Behavioral: Gaze-Contingent Feedback Training
* Behavioral: Attention Bias Modification
* Behavioral: Neutral Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Each soldier from the allocated cohort who gives written consent will be able to participate in the study. Exclusion Criteria: Hebrew proficiency is insufficient to complete the study questionnaires.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Parallel random assignment to 3 arms in 1:1:1 ratio.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Gaze-Contingent Feedback Training (toward threat)<br>In the task, 30 different matrices, each consisting of 16 faces, will be presented. Each matrix includes 8 angry faces and 8 neutral, 8 women and 8 men, and the locations are counterbalanced between matrices. The participants are asked to view the matrices in any way they choose, and the eye-tracking camera records their viewing location relative to the stimuli presented on the screen. At the beginning of each training session, the soldier will choose to which music he would like to listen during the 12-minute session from a diverse list of music. After calibrating the eye-tracker, the participant will be instructed to view matrices of faces as he chooses, as described above in the assessment task. The music chosen by the participant will play only when he is looking at threatening faces and it will stop when he looks at neutral faces. Thus, a change in viewing patterns is expected by implementing operant conditioning principles. | Behavioral: Gaze-Contingent Feedback Training<br>* Feedback according to participants' viewing patterns, in order to modify their attention toward threat stimuli.<br>|
| Active Comparator: RT-Based Attention Bias Modification (toward threat)<br>A dot-probe task of 160 trials. Trials begins with a fixation cross (+), on which the participant is asked to focus (500ms). Then two face stimuli (one angry one neutral) are presented above and below the fixation cross (500ms). After the stimuli disappear, a target probe (right- or left-pointing arrowhead) appears in place of one of the face stimuli. The participant is asked to indicate which target probe was presented using a predetermined key. The target probe will remain on the screen until response, after which a new trial will begin. Participants are instructed to identify the probe type as quickly and accurately as possible. In the training task, all of the target probes will appear in the threat location (angry face). Thus, over multiple trials, learning is expected to occurs such that the threatening face predicts the location of the target probe, thereby achieving the desired change in attention pattern. | Behavioral: Attention Bias Modification<br>* Attention training via repeated trials of a dot-probe task intended to direct attention toward threat stimuli using threat and neutral face stimuli.<br>|
| Placebo Comparator: Neutral Control<br>This condition is also based on the dot-probe task (see Active Comparator) with a fundamental difference. In this task, only neutral faces will be displayed, and therefore, while participants are exposed to the same task parameters, there will be no attention training and there will be no exposure to threat stimuli. | Behavioral: Neutral Control<br>* Dot-probe task using only neutral stimuli with no training toward threat<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-Combat PTSD Symptoms | Score on on self-report questionnaire Posttraumatic stress disorder checklist for DSM-5 (PCL-5). The total score, ranging from 0 to 80, reflects PTSD symptom severity, with higher scores representing greater severity. | Change from baseline Post-Combat PTSD Symptoms at approximately 1.5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-Combat General Anxiety | Score on self-report questionnaire Generalized Anxiety Disorder questionnaire (GAD-7). The total score, ranging from 0 to 21, reflects GAD symptom severity, with higher scores representing greater severity. | Change from baseline Post-Combat General Anxiety Symptoms at approximately 1.5 years | 
| Post-Combat Depression | Score on self-report Patient Health Questionnaire 9 (PHQ-9). The total score, ranging from 0-27, reflects severity of depressive symptoms, with higher scores representing greater severity | Change from baseline Post-Combat Depression Symptoms at approximately 1.5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Attention Bias Modification, Eye-tracking, Randomized Control Trial