Post-Traumatic Stress Disorder
Conditions
Keywords
Change blindness, Eye tracking, Implicit response
Brief summary
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.
Interventions
None listed
Sponsors
Study design
Eligibility
Inclusion criteria
* a diagnosis of PTSD based on the standard DSM-IV criteria, * normal or corrected vision. * clinically stable at the testing time
Exclusion criteria
* history of neurological illness or trauma that occurred in the previous six months, - pregnant and nursing women, * drugs use in the last 24 hours, * an acute ocular disorder. * Participants will not be under tutorship, curatorship or deprived of liberty.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Response time before the detection of neutral and emotional stimuli. | Baseline: one session | The explicit response of the participants will be measured with the response time before the detection of neutral and emotional stimuli. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of correct detections compared with the missed detections and false alarms. | Baseline: one session | 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. |
| Total duration until the participant first fixed on a ROI. | Baseline: one session | 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. |
Countries
France
Contacts
University Hospital, Lille