title: [Peculiarities of EEG dynamics in cognitive activity demanding persistent attention in patients with schizophrenia and schizoaffective psychosis and their relatives].
abstract: The search for neurophysiologic correlates of attention and working memory dysfunction in families with schizophrenia, 55 patients with schizophrenia and schizoaffective psychosis, 91 unaffected first degree relatives and 48 mentally normal subjects without family history of mental disorders have been studied. Changes in power of 5 EEG frequency bands in 16 records during serial mental arithmetic tasks were analyzed. Abnormalities in EEG reactivity were found both in patients and their relatives. Both groups were characterized by diffuse elevation of delta-rhythm power, the signs of hypoactivation and inversion of reaction asymmetry for different rhythm bands in the frontal area. In relatives, more pronounced attention dysfunction corresponded to more expressed abnormalities in EEG reactivity. Moreover, patients demonstrated insufficient depression of alpha and fast waves activity in the posterior cortex areas relevant to arithmetic activity. The results obtained allow considering an impaired reaction of alpha and fast rhythms inhibition in the posterior cortex areas as characteristic of the disease, and diffuse elevation of delta-waves power and frontal lobe hypoactivation with the inversion of reaction asymmetry as familial features that might reflect an impact of the factors predisposing to psychosis. This predisposition emerged during the cognitive task involving sustained attention and working memory.
authors.forename: L G
authors.initials: LG
authors.lastname: Uvarova
authors.forename: M V
authors.initials: MV
authors.lastname: Alfimova
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000209:etiology / Q000235:genetics / Q000503:physiopathology*; D003071:Cognition / Q000502:physiology*; D018450:Disease Progression; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011618:Psychotic Disorders / Q000150:complications / Q000235:genetics / Q000503:physiopathology*; D012559:Schizophrenia / Q000150:complications / Q000235:genetics / Q000503:physiopathology*; D012720:Severity of Illness Index