[The conditioning of the N100-P200 component of the human visual evoked potential by using biofeedback]

Subjects were instructed to modify their N100-P200 component of VEP (in Cz recording) within selected time window. The aim was to increase the number of VEPs for which the amplitude of segment in question exceeded the definite threshold. The success in task performance suggests several modifications of the to-be-conditioned segment through different mechanisms. Of our 26 subjects, 14 were able to modify their VEPs according to the task demands. However, the latter subjects could be divided into 2 groups on the basis of the rate of increase in the number of correct responses under conditioning. Subjects which did not succeed in task performance could be also classed into 2 groups: one group with statistically negligible changes and the other decreasing the number of correct responses. ANOVA has shown significant distinctions in task performance for the groups with different levels of self-estimation of tiredness after experiment and different personal strategies. The success in task performance is likely to be dependent on the values of Eysenck questionnaire scales and topography of alpha activity.