The study authors hypothesize a combination of cognitive, brain structural, brain functional and brain connectivity impairments in Suicide Attempters compared to Patient Controls and Healthy Controls, with deficits more marked in suicide attempters using violent suicidal means including: 1. Impaired choices at the reversal learning task with responses influenced by immediate outcome. This deficit would be correlated with brain activity in ventromedial Prefrontal Cortex during resting state and with several peripheral markers of the 5HT-system. 2. Reduced loss aversion. These deficits would be related to altered dynamics of Blood-Oxygen Level Dependent signal in the dorsal and ventral striatum as well as in ventral Prefrontal Cortex/ orbitofrontal cortex during the loss aversion task. These deficits would also be correlated with several peripheral markers of the 5HT-system. 3. Increased pain tolerance facilitating the execution of a violent and possibly painful act. These deficits measured with the algometer would be correlated with several peripheral markers of the 5HT-system. 4. Reduced behavioral inhibition in aversive context at the orthogonalized GoNoGo task facilitating the choice of a violent means. These deficits would be associated with altered Blood-Oxygen Level Dependent signal in ventral Prefrontal Cortex/ orbitofrontal cortex and parietal cortex during the resting state and correlated with several peripheral markers of the 5HT-system.
Study Type
OBSERVATIONAL
Enrollment
40
The computerized pressure algometer, AlgoMed (Medoc, Ramat Yishai, Israel), will be used for mechanical pain stimulation to assess information about pain threshold and tolerance. A constant rate of pressure is delivered by the examiner, and the pressure is recorded in Kilopascal (kPa). The stimulation will be applied between the medial and distal joints of the phalanges of the dominant hand.
* Two 8s sequences of spin echo field map with phase encoding AP and PA * A 12:00min bold sequence for resting-state * A 15:12min bold sequence for gambling task thickness=2mm, Matrix Size = 105×105, FOV=210×210mm2; * A 6:38min T1w MPR sequence * A 7:40min T1w MPR sequence * A 5:57min T2w SPC sequence * A 8:24min T2w SPC sequence * A 8:32min FLAIR T2w sequence * Two 8:26min Multi-echo GRE sequence * A 8:29min high resolution multi-echo GRE sequence * Two 6:46min multi-echo GRE sequence with and without magnetic transfer contrast * Two 6:03min diffusion weighted images with phase encoding AP and PA
CHU de Nimes
Nîmes, France
Brain activity between groups
Magnetic Resonance Imaging signal during the resting state and loss aversion task Blood-Oxygen Level Dependent sequences.
Time frame: Day 0
Impaired reversal learning between groups
Proportion of participants in each group reaching the learning criterion of the Reversal learning task (8 consecutive correct trials) in each stage (acquisition and reversal).
Time frame: Day 0
Loss aversion between groups
Level of acceptance/reject rate according to the size of the potential gain and loss in each trial of the Loss aversion task
Time frame: Day 1
Pain tolerance between groups
Pressure pain tolerance threshold (mean of 3 consecutive trials) measured by algometer
Time frame: Day 0
Behavioral inhibition in aversive context between groups
Response latencies in the reward-only condition vs. the reward+punishment condition in the inforced categorization task
Time frame: Day 0
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