[Contingent negative variation and mental disorders]

This work, dealing with negative contingency variation (NCV) in mental patients, is in the general frame of research aiming at establishing correlations between biological phenomenons and psychic entities. The results can be examined in three different directions. 1. In the electrophysiological perspective they have individualized a series of physiological forms and brought a real nomenclature. 2. In an electro-clinical perspective, they have allowed to oppose normal curves (NCV, type I, responses to sensory stimulations type A, B, C and motor potential type N) and abnormal curves (NCV zero or type III, IV, responses type D and motor potential type P). One must however stress that this distinction is only valid if one studies adult subjects and awaken, and contributes only an index of non specific morbidity. Furthermore, considering two more electrophysiological criteria--the mode of combination of various curves and the stability of NCV--can help establishing a severity scale and modeling the above data. 3. In a physiopathological perspective, they have lead to discussing two hypotheses concerning the functional signification of prolonged NCV; one being a prolonged state of awaiting, the other a mode of particular reaction to imperative stimulation, and to demonstrate that it is not possible to consider only one and same system to explain all clinical categories. Thus, in this new area of slow cerebral potentials, as in clinical electroencephalography, is illustrated the teaching of the functional electroencephalography through the school of Paris where similar electric patterns have different significations when present in opposed psychological organisations.