DISCRIMINATION OF LIGHT INTENSITIES AND A CHROMATIC SPACE IN RABBIT

Elaboration of differential instrumental conditioned reflexes in rabbi ts showed that probabilities of responses to differential stimuli were inversely related to differences in intensity between conditioned and differential stimuli. Factor analysis of a response probability matri x revealed two orthogonal axes. They could be interpreted as the axes of brightness and darkness in achromatic space of a rabbit. Lights of different intensities were located on a semicircle in accordance with their intensities. The experiments imply that light intensities are co ded by excitation vectors composed of responses of brightness and dark ness neurons.