A systems model for the pupil size effect. I. Transient data.
The human pupillary control system is a paradigm for linearized biological control systems. It also exhibits a series of interesting nonlinear behaviors, particularly asymmetry, "pupillary escape," and "pupillary capture." We present a nonlinear model in which a signal dependent upon pupil size is fed back internally to cause a change in system parameters related to gains and rates of light adaptation. The model was simulated on a digital computer, a variety of experimental data was well matched, and improvements over previous pupil models demonstrated. A candidate physiological mechanism for adaptive components of the model might have the form of an inverse "Henneman coded" neuronal pool.
D000818:Animals; D003201:Computers; D006801:Humans; D008433:Mathematics; D008954:Models, Biological; D011680:Pupil / Q000502:physiology*; D014785:Vision, Ocular