Electrophysiological Evaluation of Voluntary Attention

Study Overview
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Brief Summary
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Aim : To assess the ability of healthy subjects and patients with a severe motor disability to voluntary control their attention Material and Methods: Population: healthy subjects, patients with brain injury Electroencephalographic study to research attentional modulation during different kind of stimulation (visual, auditory, tactile) Sudy 1: passive recording. Study 2: active recording (instruction of attentional control given to the subject). Study 3: active recording with a feedback obtained after a processing of the brain activity.

Conditions
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Brain Injury

Intervention / Treatment
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* Other: electrophysiological evaluation
* Other: electrophysiological evaluation of patients


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Inclusion criteria for patients : Adults, man or woman, left or right-handed, from 18 years old to 80 years-old ; Diagnosis : Locked-in syndrome : < Brainstem injury, without any evolution for at least 3 week, etiology : vascular, traumatic < Amyotrophic Lateral Sclerosis < Following damage to the central or peripheral nervous system Or Minimal conscious state or Unresponsive Wakefulness Syndrome consecutive to a severe acquired brain injury for at least one month Or with a severe brain injury, since birth or acquired, for at least one month Or with Guillain-Barré syndrome Subjects affiliated to social security; Signature of consent form by the patient or by a relative (family member or the trusted person) if obtaining a consent is impossible Inclusion criteria of Healthy subjects Adults, man or woman, left or right-handed, from 18 years old to 80 years-old ; Without known auditory impairment Subjects able to understand the experimental instructions Subjects affiliated to social security; Signature of consent form Exclusion criteria of patients and healthy subjects Medical history : psychiatric disorders (except if due to brain injury), neurologic disorders (except if due to brain injury) For healthy subjects : history of brain injury Pregnant women or breastfeeding women Person under legal protection Medico-legal conflicts Absence of consent by the subject or the patient or his/her representant

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Electrophysiological assessment of Healthy subjects<br>Experiences 1, 2 and 3 with healthy subjects | Other: electrophysiological evaluation<br>* electrophysiological assessment (experience 1 : passive ; experience 2 : active versus passive ; experience 3 : active, with feedback) Experience 1, 2, 3 : one session maximum by experience<br>|
| Experimental: Electrophysiological assessment of patients<br>Experiences 1, 2 and 3 with patients | Other: electrophysiological evaluation of patients<br>* electrophysiological assessment (experience 1 : passive ; experience 2 : active versus passive ; experience 3 : active, with feedback) Experience 1 : maximum one session by sensory modality of stimulation (auditory, tactile, or visual) Experience 2 : maximum one session by sensory modality of stimulation (auditory, tactile, or visual) Experience 3 : Stimulation = auditory or visual ; possibility of several sessions if the patient is tired.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Research of statistical differences between sensory evoked potentials in attentional oriented condition and distracted condition | stastical analysis allowing to compare evoked responses during different stimulation condition (attentionnaly oriented versus attentionnally distracted versus passive condition = no instruction to the subject). These comparisons are made either for one single subject and at the group level. Analysis mainly concerns the differences in amplitude variation between the differents evoked potentials on several electrods of interest. These can vary between patients because of the different topographies of lesions and because of the different adaptative strategies. The statiscal difference will be assessed by a randomization test (also called permutation test) wich allow to assess how high is the risk that the observed difference between the evoked potential (amplitude, variance) is due to chance or not | through study completion, an average of 3 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Online and offline accuracy | percentage of correct answers with the brain-computer interface (BCI). A correct answer is recorded each time the feedback of the BCI match the command sended by the subject controlling the BCI. This analysis can be done online and offline. Online accuracy is recorded in real-time during the session with the subject. offline accuracy is obtained a posteriori of the experiment, to test the impact on accuracy of the changes in different parameters (stimuli duration, numbers of spatial filtering, change of classifiers, etc.). | through study completion, an average of 3 years. | 
| Clinical scale score (Evaluation de la Communication des patients en Eveil de Coma (ECEC) scale) | this clinical scale allow to obtain an outcome measure of the investissment, the communication themes and the communication modes of the patient. The final global value range between 0 and 44. | an average of 3 years (At the group level) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Voluntary attention, Electroencephalogram, Brain-computer interface, Disorders of consciousness