Post-traumatic stress disorder (PTSD) is characterized by hypervigilance. In particular, previous works suggest that patients tend to scan constantly the environment for possible threats. The present project aims at investigating such attentional bias in patients with PTSD using the change blindness paradigm that offers the interesting possibility of studying sensitivity to sudden changes using ecological stimuli. More precisely, the investigators will investigate whether patients are more sensitive than matched controls to sudden changes in the visual environment and whether this hypersensitivity is specific or even stronger when visual information has an emotional content. The attentional bias will be measured using motor responses (accuracy and speed to indicate the occurrence of a change by pressing a button) as well as eye movements.
Study Type
OBSERVATIONAL
Enrollment
80
University Hospital, Lille
Lille, France
Response time before the detection of neutral and emotional stimuli.
The explicit response of the participants will be measured with the response time before the detection of neutral and emotional stimuli.
Time frame: Baseline: one session
Number of correct detections compared with the missed detections and false alarms.
Performances will be measured by a sensitivity index (D prime) . This sensitivity index considers the number of correct detections compared with the missed detections and false alarms.
Time frame: Baseline: one session
Total duration until the participant first fixed on a ROI.
The implicit response will be measured by the localization and duration of fixations. All fixations outside the recording field will be excluded. The main variable will be the mean latency of the first fixation in a region of interest (ROI). This variable corresponds to the total duration until the participant first fixed on a ROI.
Time frame: Baseline: one session
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.