Efficiency of photostimulation controlled by subject’s EEG decreases under the conditions of feedback delay

Abstract

One of the central problems in the study of brain–computer interface and the processes of operant conditioning is the optimal organization of feedback signals. In this paper we have analyzed the question about comparative efficiency of immediate or 2.56-s delayed presentation of feedback signals as photic stimulation automatically controlled by subject’s electroencephalogram (EEG). Strictly controlled experiments showed a significant increase in EEG power and positive shifts in subjective characteristics only under the minimum feedback delay, i.e., in cases where photic stimuli are controlled directly by the current EEG characteristics of the subjects.