Cognitive Assessment by the Mean of Event Related Potentials

The main objective of this study is to describe differential cognitive processing of various stimuli by a population of control subjects and a population of patients with selective cognitive deficits or altered states of consciousness by using dedicated ERP paradigms and high-density EEG picked up system.

In order to test the relevance of theoretical models of cognitive functions, examination of patients with cerebral lesions is of great interest. Thus, the goal of this study is to assess cognitive processing in patients by a combination of behavioural clinical tests and ERP (event related potentials) specific markers. Indeed, ERP technique makes it possible to ascertain that a patient or control subject has or has not performed the task we asked him to even if the subject performs the task covertly. From these ERPs markers, we can investigate their respective cortical generators. By comparing the results obtained in both healthy and pathological populations, we will be able to appreciate differential processing of the same stimuli by two different populations and try to correlate these differences with specific cerebral lesions and with different outcomes.We previously demonstrated the relevance of this approach in the field of disorders of consciousness patients and we project to enrich this specific approach by the addition of new markers and by its extension to other fields of cognitive and behavioural neurology.

The procedure will be the following. After obtaining written informed consent, patients will be examined clinically with dedicated specialized scales (for example the CRS-R for disorders of consciousness patients). Then, we will probe event related potentials by stimulating these patients with various stimuli embedded in well-designed paradigms while their scalp EEG will be recorded. Following different steps of signal processing the mean ERPs according to conditions will be extracted and statistical analysis will be performed. At one year from the recording, outcome will be collected and correlated with the obtained ERPs.

Eligibility Criteria:
Control subjects

Inclusion Criteria:

* adults between 18 and 80,
* written informed consent obtained from the subject,
* covers by social insurance,
* absence of psychoactive drug intake in the week preceding the examination or alcohol intake the day before the exam

Exclusion Criteria:

* pregnant patients or breastfeeding,
* sensory deficit incompatible with the participation in tne study,
* person under a legal protection measure, under guardianship,
* psychoactive drug intake in the week preceding the examination or alcohol intake the day before the exam

Patients :

Inclusion Criteria:

* adults between 18 and 80,
* written informed consent obtained from the patient or his relatives,
* covers by social insurance,
* patients with either focal or diffuse brain damage drom trauma, vascular, tumor or other aetiologies, or with a history of neonatal or congenital diseases,
* patients with selective cognitive disorders or with altered states of consciousness

Exclusion Criteria:

* Pregnant patients or breastfeeding,
* sensory deficit incompatible with the participation in the study