title: [Induced cortical electrical activity during different time-spans between warning and target stimuli].
abstract: A certain alpha-band EEG dynamics was revealed in healthy adults (n = 16) at the interval between a warning and a target stimulus in a simple visuospatial task (subjects were instructed to locate a specific letter in the table of letters). Two series of experiment--either with a 2-sec or a 9-sec inter-stimulus interval were conducted, each consisting of 60 trials. In both series, we observed an induced desynchronization of low alpha (8-10 Hz) at the first second after the warning stimulus and its desynchronization just before the target stimulus. In series with a 9-sec inter-stimulus interval at the 4-6 s of it we observed an alpha-band synchronization, especially distinct in high alpha (10.5-13 Hz). This synchronization gradually reduced towards the end of the inter-stimulus interval. We consider the above changes in alpha-band spectral power during the inter-stimulus interval to be induced by "inner impulsations" caused by an internal representation (set) of the stimuli time-sequence. Changes in the level of cognitive control during the inter-stimulus interval cause increases and decreases in fronto-thalamic system activity, which are manifested in changes of alpha-band spectral power. Analysis of theta-band dynamics suggests that cortico-hippocampal system doesn't participate in this process.
authors.forename: Ē A
authors.initials: ĒA
authors.lastname: Kostandov
authors.forename: E A
authors.initials: EA
authors.lastname: Cheremushkin
authors.forename: M L
authors.initials: ML
authors.lastname: Ashkinazi
authors.forename: I A
authors.initials: IA
authors.lastname: Iakovenko
mesh_terms: D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003344:Cortical Synchronization; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D012718:Set, Psychology; D013826:Theta Rhythm / Q000502:physiology