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

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

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: 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 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. 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. 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).

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 veteran 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-tracking technology, the veteran will be instructed to view the matrices of faces as he chooses, as described above in the assessment task. The music chosen by the veteran will play only when s/he is looking at neutral faces and it will stop when s/he looks at threatening faces.

The task consists of 160 trials. Each trial begins with a centrally-presented fixation cross (+), on which the participant is asked to focus for 500ms. When it disappears, two stimuli will be presented 1.5cm above and below the previous fixation cross for 500ms. After the stimuli disappear, a target probe (right- or left-pointing arrowhead) will appear in place of one of the stimuli, and the participant will be asked to indicate which target probe is presented by pressing the respective key. The target probe will remain on the screen until the participant's 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 neutral face location. Thus, over multiple trials, learning occurs that the threatening face predicts the location of the target probe, thereby achieving the desiring change in attention patterns.

This condition is based on the aforementioned eye-tracking task with a fundamental change - The music chosen by the veteran will play continuously without any reinforcement for looking at threat or neutral faces.

Feedback according to participants' viewing patterns, in order to modify their attention away from threat face stimuli.

Attention training via repeated trials of a dot-probe task intended to direct attention away from threat stimuli using threat and neutral face stimuli.

Participants listen to a musical track they chose while viewing the face matrices. The music is played throughout and is not contingent upon gaze behavior.

Change in PTSD diagnosis, derived from CAPS-5 corresponding to DSM-5 criteria, from pre- to post-treatment

Change in score on self-report questionnaire Posttraumatic stress disorder checklist for DSM-5 (PCL-5) from Pre- to Post-Treatment. The total score, ranging from 0 to 80, reflects PTSD symptom severity, with higher scores representing greater severity.

Score on self-report questionnaire Posttraumatic stress disorder checklist for DSM-5 (PCL-5) at 3-month Follow-up. The total score, ranging from 0 to 80, reflects PTSD symptom severity, with higher scores representing greater severity.

Change in Score on self-report Patient Health Questionnaire 9 (PHQ-9) from Pre- to Post-Treatment. The total score, ranging from 0-27, reflects severity of depressive symptoms, with higher scores representing greater severity.

Score on self-report Patient Health Questionnaire 9 (PHQ-9) at 3-month Follow-up. The total score, ranging from 0-27, reflects severity of depressive symptoms, with higher scores representing greater severity.

Clinician Rated Symptom Severity & Improvement. Severity and improvement scales (CGI-S/I) will be used to assess participants global clinical condition. The CGI-S and the CGI-I are single-items, clinician-reported, measure assessing severity and improvement of illness using a 7-point Likert-type scale. The CGI-S/I has good inter-rater reliability and concurrent validity with other measures. This tool is widely used in clinical trials concerning psychopathology treatments and has good sensitivity to clinical change.

Clinician Rated Symptom Severity & Improvement. Severity and improvement scales (CGI-S/I) will be used to assess participants global clinical condition. The CGI-S and the CGI-I are single-items, clinician-reported, measure assessing severity and improvement of illness using a 7-point Likert-type scale. The CGI-S/I has good inter-rater reliability and concurrent validity with other measures. This tool is widely used in clinical trials concerning psychopathology treatments and has good sensitivity to clinical change.

Change in Attention Bias will be assessed with two scores, one resulting from a response-time based dotprobe task and another from an eye-tracking computer task.

Attention Bias will be assessed again at the 3 month follow-up. It will be measured with two tasks, one response-time based dotprobe task and an eye-tracking computer task.

Change in Behavioral Attention Control from Baseline to Post-training Measurement will be assessed using a Flanker computer task.

Behavioral Attention Control will be assessed again at 3-month Follow-up using a Flanker computer task.

Change in score on self-report Attention Bias Questionnaire (ABQ) from Baseline to Post-treatment. The total score, ranging from 0 to 36, represents threat-related attention bias, with higher scores representing greater bias toward threat.

Score on subjective Attention Bias Questionnaire (ABQ) at 3-month Follow-up. The total score, ranging from 0 to 36, represents threat-related attention bias, with higher scores representing greater bias toward threat.

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.

Lazarov A, Pine DS, Bar-Haim Y. Gaze-Contingent Music Reward Therapy for Social Anxiety Disorder: A Randomized Controlled Trial. Am J Psychiatry. 2017 Jul 1;174(7):649-656. doi: 10.1176/appi.ajp.2016.16080894. Epub 2017 Jan 20.