By means of EEG analysis the functional state of subjects with high and low levels of anxiety was studied in different periods preceding a cognitive task - a visual expression recognition. Several conditions were investigated: background/eyes closed; background/eyes opened; listening the instruction for the cognitive task; operative rest (time lapse between listening the instruction and the beginning of the task), as well as short intervals immediately preceding the exposition of target stimuli (stage of preparation) - pairs of faces pictures with identical or different emotional expressions. At all these pre-task stages high-anxiety subjects exhibited much lower amplitude values in alpha and theta bands (as compared with low-anxiety subjects). The most prominent differences were revealed in the phases of instruction listening and operative rest. These data could provide more precise electrophysiological markers of anxiety level in conditions preceeding cognitive task performance.
Keywords: Anxiety; EEG; alpha rhythm; face recognition; prefrontal cortex; preparatory processes.