Abstract

The purpose of the research was to determine the role that photon noise plays in setting the increment threshold, using an idea introduced by Krauskopf and Reeves (1980). The state of photoreceptor and neural adaptation is fixed by exposure to a steady adapting light. The role of photon noise is then deduced by comparing thresholds for test flashes on the adapting field (‘ON’ thresholds) with thresholds obtained just after the field has been turned off (‘OFF’ thresholds).

© 1995 Optical Society of America