Item

Abstract

This chapter studies the optokinetic reactions of the beetle Chlorophanus to relative movement of its optical surroundings. Many animals react to optical stimulation by moving the eyes, the head, or even the whole body. These reactions are called “optomotor responses,” and they are continuously graded functions of optical stimulation. These reactions are elicited not only from the movement of figures distinguishable against their backgrounds but also from the movement of randomly constructed patterns of shades from white through black. The stimuli received by the ommatidia are linearly transformed, and their interaction in the central nervous system is in accordance with the principle of first-order correlation. As a consequence of this evaluation principle in Chlorophanus, the class of all optical surroundings that differ from each other by different phase relations of their Fourier components produce the same optomotor responses for any pattern velocities.