Influence of simple verbal and non-verbal stimuli on brain electrical activity.

In this study, the influence of analysis stimulus content on the reaction time (RT) and parameters of the brain activity was investigated. Thirty healthy right-handed volunteers (mean age 24 years) participated in the study. The dynamics of RT, characteristics of electroencephalogram (EEG) and event-related potentials (ERP) components during perception of digits and non-verbal stimuli were analyzed. The specificity of RT's asymmetry in simple and complex visual-motor reactions depended on stimulus type was revealed. The similarity of early ERP components (peak latency of 100-200 ms) for both stimuli types in simple and complex visual-motor reaction was shown. We also described the formation of specific ERP configuration for digits differentiation such as a left-sided asymmetry of component N200, and increase of peak latency of the late negative component with their extension to the parietal region.