| 摘要 |
FIELD: medicine. SUBSTANCE: method involves showing luminous flickers of given initial frequency. Then, initial and incremental frequencies and initial and decremental frequencies are shown alternatingly with constant period. Shown frequencies difference is varied until the testee determines discrimination threshold of frequencies shown in succession. Incremental frequency is increased at the first stage until the testee determines the moment the frequencies shown in turn become surely different. Then the incremental frequency is reduced until the testee determines the moment the frequencies shown in turn stay surely undistinguishable. The second stage involves making measurements like those of the second one but with incremental frequency variation speed being smaller. The incremental frequency of luminous flickers determined at the second stage is slowly varied at the third stage until the testee determines discrimination threshold of frequencies shown. Threshold value is calculated as difference between the incremental frequency determined at the first stage and the initial one. The fourth, fifth and sixth stages involve making measurements like those of the first, second and the third one but with initial and decremental luminous flickers frequencies being shown. Spatial frequency canal band pass is determined as arithmetic mean frequency thresholds determined at the third and the sixth measurement stages. EFFECT: simplified procedure; reduced influence of orientation, dimensions and brightness of visual stimuli. 2 dwg |
