[Interindividual variability of contingent negative variation].

The use of CNV in clinical practice requires the choice of a standardised protocol, the constitution of reference normative data and the consideration of intra- and interindividual variability. For this purpose, we recorded CNV in 86 control subjects (44 men and 42 women, 18 to 62 years old (mean age = 34 +/- 13 years) during a reaction time paradigm with a warning signal and a 1-second S1-S2 interval. Moreover, the role of inter-stimulation interval was analysed in a group of 12 subjects through the comparison of recordings made with 1- and 3-second intervals.

[Interindividual variability of exogenous and endogenous auditory evoked potentials in a condition of voluntary attention].

The use of P300 in psychopathology raises the important problem of the constitution of reference normative data and of the high variability of auditive ERP's in controls. To handle better this problem, we recorded 86 control subjects, using an auditory oddball paradigm with motor response. We analyzed the successive components of the ERP's evoked by target and standard stimuli (N1, P2, N2, P3a, P3b and slow wave negativity).

[Biological markers in schizophrenia].

Based on a review of the literature, the article deals with the major biological markers of schizophrenia. Recent developments in molecular biology have shown a possible association between schizophrenia and various HLA markers (A1, A2, A9, A10, A28, B27, BW16), and a linkage--in several families--between the disease and some polymorphisms of chromosome 5. On the other hand, chromosome X might also be involved.

[The value of cognitive psychophysiological studies in a comprehensive approach to schizophrenia (treatment of information and attention capacities in acute-stage schizophrenia)].

According to information processing theory, attention deficits appear to be a nuclear disorder in schizophrenia which the study has been renewed with the development of neurophysiology technique. The originality of our research was to study in a same subject Event-Related-Potentials in three different conditions: passive and active auditory oddball paradigm for Mismatch Negativity (MMN) and P 300, and a simple reaction time task with warming stimulus for the Contingent Negative Variation (CNV). The study was carried out among 20 schizophrenic subjects (paranoid subtype with acute exacerbation, DSM-III-R) and 20 healthy volunteers.