The CNV and its Relation to Specific Psychiatric Syndromes

Event-related slow (DC) potentials in the human brain

“…The highest incidence of small CNVs was found in psychotics (in agreement with McCallum 1966McCallum , 1967bMcCallum and Walter 1968;Small and Small 1971 ;McCallum and Abraham 1973 ;Abraham et al 1976). The highest incidence of prolonged CNVs was found in psychotics (in agreement with McCallum 1969; Timsit et al 1970).…”

“…The initial amplitude was smaller and the reduction by distraction was more pronounced in cases with more severe symptoms. In a more recent study (Abraham et al 1974(Abraham et al , 1976 using another group of schizophrenics, acquisition and distraction amplitude, prolongation and parietal spread [amplitude difference between vertex (C z) and postcentral midline derivation (Pz)] were investigated, the subjects being without medication at the first test. The earlier observations were confirmed: prolongation tended to disappear with treatment and improvement.…”

Self-regulation of slow cortical potentials in psychiatric patients: Depression

“…Findings of such electrophysiological investigations were nosologically nonspecific: Observations of depressives in comparison to schizophrenic patients suggested a trend toward smaller Contingent Negative Variation (CNV) and a tendency to produce prolonged Postimperative Negative Variations (PINV) (Abraham & McCallum, 1976;Bolz & Giedke, 1980;Claverie, Brun, Nizard, Brenot, & Paty, 1984;Elton, DeJong, & Ferstl, 1980;Rizzo et aI., 1979;Roth, Duncan, Pfefferbaum, & Timsit-Berthier, 1986;Sartory, 1986;Small & Small, 1971;Timsit-Berthier, Delaunoy, Koninckx, & Rousseau, 1973;Timsit-Berthier et aI., 1986). In normals this PINV occurs only in experimental situations of unexpected contingencies or loss of control over aversive events or unpredictably gained control (Kathmann, Jonitz, & Engel, 1990).…”

Contingent Negative Variation and Attention in Schizophrenic and Depressed Patients

“…In schizophrenic patients a diminution and sometimes a prolongation of CNV extending beyond S2 are well established [16][17][18][19][20][21]. The intensity of the CNV diminution has been related to the expression of positive, florid symptoms [14,[16][17][18][19][20][21][22]. The close linkage between CNV diminution and the severity of psychopathological symptoms [23,24] is further underlined by the finding that, after complete remission, a CNV tends to normalize [24,25].…”

“…CNV alterations have been shown to be associated with psychotic states and with the severity of psychopathology in general [14,15]. In schizophrenic patients a diminution and sometimes a prolongation of CNV extending beyond S2 are well established [16][17][18][19][20][21].…”