[Evoked brain potentials and perception errors]

Visual evoked potentials were studied in a psychophysical experiment based on discrimination of two phtoic flashes of different brightness. EP were summarized in accordance with the four experimental results: correct detection, misses, false alarms and correct rejection. It was found out that EP parameters are in a rather precise correspondence with the perceived brightness of stimuli. The subjective brightness depends in its turn, on two factors: intensity of stimulation and sensitivity of sensory input. Maintenance of sensitivity at a constant level provides for the precision of perception. On the contrary, the changes in sensitivity lead to errors in detection. The data obtained show that these changes may result from the shift of brain DC potential.