Abstract

In humans, the pupil does not only responds to changes in luminance levels, but also respond to isoluminant color changes (e.g., Kohn and Clynes, 1969; Young and Alpern, 1980). This raised new possibilities regarding the nature of the underlying visual process, such as some aspects of the process may be "color-opponent", there may be multiple processes with different preferences for luminance and chromaticity, or the underlying visual process may be mediated by phasic (M-like) and/or tonic (P-like) visual neurons.

© 1995 Optical Society of America