| Autor: |
Fermi, Giulio, Richardt, Werner |
| Zdroj: |
Kybernetik; 1963, Vol. 2 Issue 1, p15-28, 14p |
| Abstrakt: |
The torque exerted by the housefly Musca domestica during fixed flight was used as a measure of the optomotor reaction of the insect elicited by the rotation of cylindrical patterns with periodic distributions of surface brightness. Measurements were made of the dependence of the reaction on the wave length, speed of rotation, contrast, and mean brightness of the stimulus patterns. The effect on the reaction of modulation of the light illuminating the stimulus pattern was examined. Further experiments indicated that stimulation of only one of the two complex eyes is sufficient to elicit an optomotor reaction, and that there is overlap between the visual fields of neighboring photoreceptor units in the complex eye. Estimates of the rates of absorption of light quanta by individual ommatidia in the complex eye indicated that these rates are low enough that the Poisson statistics of the light quanta results in a significant level of noise in the light signals received by the photoreceptors, when the brightness of the stimulus pattern is low but still sufficient to elicit a measurable reaction. The contrast that is required of a rotating stimulus pattern in order to elicit a just-measurable reaction was found to depend upon the mean brightness of the pattern in a manner that is consistent with the hypothesis that the noise due to the statistics of the light quanta absorbed by the photoreceptors in the complex eye is a principle cause of the breakdown of the optomotor reaction at low values of the contrast and mean brightness of the stimulus pattern. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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