Abstract

Ideal observers incorporating different stages of visual processing allow one to calculate the efficiency with which human observers use discrimination information available at chosen processing stages. I will discuss two examples of this in the study of spatial vision. First, we examined the contributions of preneural mechanisms (that is, optics and photoreceptor properties) to eccentricity-dependent variations in spatial vision in adults by comparing the contrast sensitivity and visual resolution of ideal observers with those of human adult observers. Second, we examined the contributions of these front-end mechanisms to age-related changes in contrast sensitivity and acuity by again comparing ideal observer performance to that of human neonates. In both cases, we found that much, but not all, of the sensitivity and acuity variations (with eccentricity or with age) can be understood from an analysis of information losses in the front-end.

© 1992 Optical Society of America