Spatial pattern of electroencephalogram rhythms in right-handed students with different anxiety levels at rest and during examination stress

Objective. The objective of the study is to conduct comparative analysis of EEG activity in the right and left cerebral hemispheres both during the intersession and examination periods in right-handed students with different levels of sinistrocerebral dominance and anxiety. Materials and Methods. During the trial 73 right-handed students aged 18 to 20 years were examined. Hemispheric dominance was determined according to the coefficient on right-handedness. The level of state anxiety was estimated by Srielberger-Hanin test (State-Trait Anxiety Inventory). Student's EEG rhythms were recorded unipolarly in standard leads according to the international scheme «10-20» by «NVX 36 digital DC EEG». The rhythms were recorded in two conditions: students being quite awake during the intersession period and under stress during the examination. Amplitude of alpha-, beta-, delta-and theta-waves and EEG power spectrum in standard frequency ranges was analyzed. Results and Discussion. During the intersession period alpha-waves dominated in students' EEGs. In the left frontal lobe delta- and theta-waves were also observed. They were extremely evident in partial righthanded students with a high anxiety level. Under the examination stress there was an increase in low frequency EEG activity in the left frontal lobe in all right-handers. Besides there appeared delta-waves in the right frontal lobe in true and partial right-handers with middle and high anxiety levels. Conclusion. The results obtained indicate that increase of low-frequency EEG activity in frontal lobes is an important electrophysiological correlate of the intensity of cognitive functions and the marker of examination stress. The latter is more evident in right-handers with a high anxiety level.