[Changes of the l and upper alpha frequency oscillating during time intervals between meaningful visual stimuli].

In healthy adults (n = 35) was used the model of the cognitive set to emotionally negative facial expression ("angry face"). In order to load the working memory was lengthened the time interval between target (face) and trigger stimuli. In cases of the flexible set (no errors in recognition of facial expression was accompanied switching or updating the set) the induced high frequency alpha oscillations (10.5-13 Hz) were more pronounced than in subjects with the rigid set (six and more errors). The role of the "top-down cognitive control" in providing flexible form of cognitive sets are discussed.