FIELD: medicine.
SUBSTANCE: show light flickers with use of 10 pairs light-emitting diodes to the examinee; one of 10 buttons corresponds to each of them. Frequency of light flickers of the first light-emitting diodes in pairs does not change. At the first stage of measurements on the second light-emitting diode of the first pair submit light flickers with the frequency enlarged in comparison with frequency of the first light-emitting diode on 0.5 Hz. On every second light-emitting diode of the subsequent pair submit light flickers with the frequency enlarged in comparison with frequency of the second light-emitting diode of the previous pair on 0.5 Hz. The examinee defines pair light-emitting diodes with the least number, frequencies of which light flickers differ, and presses the button corresponding to it. At the second stage of measurements on the second light-emitting diode of the first pair submit light flickers with frequency, smaller on 0.5 Hz of frequency of the second light-emitting diode of the pair defined at the first stage by the examinee as pair, frequencies of which light flickers differ. On every second light-emitting diode of the subsequent pair submit light flickers with the frequency enlarged in comparison with frequency of the second light-emitting diode of the previous pair on 0.1 Hz. The examinee defines pair light-emitting diodes with the least number, frequencies of which light flickers differ, and presses the button corresponding to it, fixing value of frequency of light flickers of the second light-emitting diode of this pair. Value of a differential threshold of frequencies of light flickers is calculated as a difference between the frequency of a light-emitting diode fixed at the second stage and initial frequency. At the third stage of measurements on the second light-emitting diode of the first pair submit light flickers with the frequency reduced in comparison with frequency of the first light-emitting diode on 0.5 Hz. On every second light-emitting diode of the subsequent pair submit light flickers with the frequency reduced in comparison with frequency of the second light-emitting diode of the previous pair on 0.5 Hz. The examinee defines pair light-emitting diodes with the least number, frequencies of which light flickers differ, and presses the button corresponding to it. At the fourth stage of measurements on the second light-emitting diode of the first pair submit light flickers with frequency, less on 0.5 Hz of frequency of the second light-emitting diode of the pair defined at the first stage by the examinee as pair, frequencies of which light flickers differ. On every second light-emitting diode of the subsequent pair submit light flickers with the frequency reduced in comparison with frequency of the second light-emitting diode of the previous pair on 0.1 Hz. The examinee defines pair of light-emitting diodes with the least number, frequencies of which light flickers differ, and presses the button corresponding to it, fixing value of frequency of light flickers of the second light-emitting diode of this pair. Value of a differential threshold of frequencies of light flickers calculate as an absolute difference between the frequency of the second light-emitting diode fixed at the fourth stage and initial frequency. A pass-band of the spatially-frequency channel is defined as an average arithmetic value of differential thresholds of frequencies of the light flickers calculated at the second and fourth stages of measurements.
EFFECT: allows defining a pass-band of the spatial frequency channel of visual system.
1 dwg, 4 tbl, 1 ex
Authors
Dates
2008-12-20—Published
2007-10-01—Filed