Neurobehavioral moderators of post-traumatic stress disorder (PTSD) trajectories: study protocol of a prospective MRI study of recent trauma survivors

Figures & data

Table 1. Cognitive measures. Specific cognitive tests, measured constructs, instructions for participants, and outcome measures of the cognitive measures which will be used in the study.

Tests	Measured construct	Instructions	Outcome measures
1. Tapping test	Motor coordination	Participants will be required to tap the space bar with their index finger, as fast as possible for 30 seconds.	Number of Taps, Variability of Pauses Between Taps.
2. Reaction time test	Processing speed	Participants will be presented with two black circles on the screen. When the left circle will turn green, they will be instructed to press the left arrow button as fast as possible with their left hand. When the right circle will turn green, they will be instructed to press the right arrow button as fast as possible with their right hand.	Reaction Time.
3. Verbal memory test (Immediate)	Recall memory	A list of twenty words will be presented one by one. Individuals will then be presented with twenty sets of three response words (one word from the list and two new words). For each set of three words, they will be instructed to select the one word that was previously presented.	Total Accuracy and Reaction Times for Immediate Recall Responses.
4. Verbal memory test (Delayed)	Recall memory	Ten minutes later, after several other tasks, individuals will again be presented with twenty sets of three response words (one word from the list and two new words). For each three words, they will be instructed to select the one word that was previously presented.	Total Accuracy and Reaction Times for Delayed Recall Responses.
5. Emotion identification test	Emotion identification	This task will include a series of faces that will be presented on the screen, each displaying one of six emotional expressions (fear, anger, disgust, sadness, happiness, or neutral). On each trial, participants will have to select the emotion label that best matches each face from the six response buttons displayed beneath the face, as quickly and as accurate as possible.	Accuracy and Reaction Time will be measured for each one of the six emotional faces types separately.
6. Emotional bias test	Emotional bias	Ten minutes later, after several other tasks, participants will be presented with different sets of two emotional faces, one which will be identical to a face presented in the previous task (Emotion Identification task), and a second new face. Individuals will be instructed to use the mouse to determine which of the two faces was presented in the previous task.	Accuracy and Reaction Time will be measured for each one of the six emotional faces types separately.
7. Digit span test	Working memory	Participants will be presented with a series of digits on the screen (one by one) and will then be instructed to type them in the exact order in which they were displayed.	Maximum Recall Span, and Correct Trials.
8. Stroop task (Stroop, 1935)	Controlled attention	Participants will be presented with colour names printed in either “matched” (e.g. the word RED printed in red ink) or “mismatched” colours (e.g. the word RED printed in green ink). In the first part, they will be asked to indicate the meaning of the word, while disregarding the ink colour. In the second part, they will have to do the opposite, meaning to indicate the ink colour, while disregarding the meaning of the word.	Reaction Time and Accuracy for each Type of Condition (Congruent/Incongruent), Number of Congruent and Incongruent Trials Completed (in 20 seconds).
9. Trail making test (Reitan, 1958)	Cognitive flexibility	Participants will be asked to connect 25 circles according to the correct order, as fast as possible. In the first part, they will be presented with 25 numbers and will have to connect them by order (from 1 to 25). In the second part, they will be presented with a combination of 13 numbers (1–13) and 12 letters (A-L) and will be instructed to switch back and forth between numbers and letters in an ascending pattern (e.g. 1-A-2-B, etc.). Note: to match mother tongue we will use Hebrew letters.	Response Accuracy, Completion Time and Connection Time.
10. Inhibition test (Go/No-Go Task)	Response inhibition	Participants will be instructed to press the space bar when the word appears in green and to inhibit their response when the word appears in red.	Accuracy, Errors of Commission and Omission, Reaction Time and its Variability.
11. Maze Task	Executive function	Participants will be presented with an 8 × 8 matrix of red circles. They will be required to discover and remember a fixed, hidden path through the grid, from a yellow starting dot on the bottom row to a blue finishing dot on the top row while receiving feedback during the task. A total of 24 correct moves is required to navigate to the finishing dot. The task will end when the full path is completed without errors twice in a row, or when the maximum task duration of 5 minutes is reached.	Trials completed, Completion time, Path learning time, Total errors and Overrun errors.
12. Continuous performance test	Sustained attention	Participants will be presented with a serious of letters and will be instructed to respond when they detect the same letter appears twice in a row. The task includes 63 stimuli, with 12 ‘response’ trials where the same letter is repeated twice in a row. Task duration is approximately 3 minutes.	Accuracy, False Miss Errors, False Alarm Errors, Reaction Time and its Variability.
13. Emotional stroop test	Emotional bias	Participants will be presented with a facial expression of ‘happiness’ or ‘fear’, together with the word ‘happy’ or ‘fear’ placed on the face. The participant will be instructed to indicate the facial expression, while ignoring the word placed on it. Participates are guided to make their response as accurate and quickly as possible.	Accuracy and Reaction Time for Congruent and Incongruent Trials, Reaction Time for Interference.

Figure 1. Study flowchart.

Stroop, J. R. (1935). Stroop color word test. Journal of Experimental Pathology, (18), 643–662. doi:10.1007/978-0-387-79948-3

 Google Scholar

Reitan, R. (1958). Validity of the trail making test as an indicator of organic brain damage. Perceptual and Motor Skills, 8, 271–276.

 Google Scholar

Data availability statement

The datasets which will be used and/or analyzed during the current study will be available after QA and once brought to maturity, by contacting the study PI on reasonable request.