title: [The functional brain organization during preparation for recognizing incomplete images].
abstract: The functional interaction between prefrontal cortex and other cortices was analyzed during the pre-stimulus period in the task in which human subjects (n = 36) were asked to recognize a set of incomplete images of different degree of fragmentation. The imaginary part of the complex-valued coherency was used to measure a strength of inter-area coupling at the alpha-rhythm frequency. Based on the analysis of individual responses the two equal sub-groups (n = 13) showing the lowest and highest recognition scores were extracted from the whole group of subjects. It is shown that the pattern of the functional cortico-cortical interactions as well as the direction of its' changes differ in the two sub-groups. In those subjects who successfully solve the cognitive task, the changes in functional connectivity indices in the situation of focused attention are most pronounced in the right hemisphere if stimulus-to-come would not be recognized. Period preceding recognized stimulus is characterized by the increased cortico-cortical coupling in the left hemisphere. In that sub-group, the values of imaginary part of alpha-coherency show the growth in both hemispheres when the period of focused attention is compared against the period of nonspecific attention. On the contrary, the similar comparison for the sub-group of the least successful subjects shows the imaginary coherency decreases in both hemispheres. These results suggest the constructive role of the alpha-rhythm in functional assembling the prefrontal cortex during the period that precedes the recognition of incomplete images.
authors.forename: D A
authors.initials: DA
authors.lastname: Farber
authors.forename: R I
authors.initials: RI
authors.lastname: Machinskaia
authors.forename: A V
authors.initials: AV
authors.lastname: Kurganskiĭ
authors.forename: N E
authors.initials: NE
authors.lastname: Petrenko
mesh_terms: D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology*; D001931:Brain Mapping; D004566:Electrodes; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007092:Imagination / Q000502:physiology*; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology*; D013647:Task Performance and Analysis; D014584:User-Computer Interface