EEG Activity in Dextrals and Sinistrals during Visual Monocular/Binocular Perception of Verbal Emotionally Colored Information

Abstract

We compared the characteristics of EEG during mono- and binocular performance of the Stroop test. Either emotionally colored words or “pseudowords” were presented as stimuli; among 60 examined subjects, there were 30 sinistrals with dominant left eye and 30 dextrals with dominant right eye. In right-handed subjects, the coherence of theta oscillations in central and parietal pairs of the leads increased during binocular perception of verbal emotionally colored information, while a rise in the level of coherence of high-frequency beta oscillations in intrahemispheric lead pairs was observed in left-handers under the same conditions. In the course of binocular performance of both types of tests, interhemispheric coherence was altered, while changes of coherence were found only within one hemisphere during monocular perception. In dextrals, the level of synchronization of the activity in local networks demonstrated a significantly higher rise in the left hemisphere in the case where pseudoword signals were used. In sinistrals, such an increase was observed in both hemispheres together with a decrease in the interhemispheric interaction. In tests of both types during monocular perception of both emotionally colored words and pseudowords via a dominant eye, EEG activity was rather similar in both dextrals and sinistrals. This fact may indicate that nonrelevant semantic context of the stimuli during processing of information incoming via the dominant visual canal is mostly ignored.