DIFFERENCE IN HUMAN VEP DEPENDING ON A CA PABILITY FOR BIOFEEDBACK CONTROL OVER VEP PARAMETERS

The individual characteristics of the VEP spatio-temporal patterns wer e studied depending a capability of a subject for VEP biofeedback cond itioning. Thirty two healthy adult volonteers had to modify their N100 -P200 VEP component (Cz derivation) within a selected time window in o rder to increase the number of trials in which the amplitude of the se gment from the beginning of the sample to the positive peak exceeded a definite threshold. In addition to traditional visual assessment of t opographical maps, the statistical analysis of multichannel VEPs and c omponent analysis for Cz, O1, and O2 were carried out for each discret e time sample. The differences were observed in the spatio-temporal VE P patterns for successful and unsuccessful performance. In the backgro und sessions, the central and occipital P200 components were much the same in the subjects which succeeded in task performance, whereas the central component was noticeably higher than the occipital one in the subjects who were unsuccessful in biofeedback control. During successf ul performance, there was a reduction of the occipital P200. Thus, the relationships of VEP components in the central and occipital derivati ons can predict successful biofeedback conditioning and may reflect th e prevalence of verbal and non-verbal thinking.