Abstract

An earlier paper [ J. Opt. Soc. Am. A 1, 775 ( 1984)] described a general ideal discriminator (a Stimuli-Defined-Exactly observer) whose sensitivity is limited only by the initial sequence of mechanisms in the visual system—the optics of the eye, the receptor lattice, receptor optics, and photopigment spectral sensitivities. In the present paper, further properties of the model are derived, and a similar model (a Stimuli-Defined-Statistically observer) is developed for conditions with stimulus uncertainty. To test the predictions of the models, two-point intensity discrimination, resolution, and separation discrimination were measured as a function of point-source energy and background luminance. Three important differences between resolution and separation discrimination were found: (1) At moderate to high intensity levels, separation threshold is-much smaller than resolution threshold. (2) At low intensity levels, resolution threshold is smaller than separation threshold. (3) Separation threshold decreases more rapidly than resolution threshold as a function of intensity. All three properties were predicted by the models. However, as expected, the quantitative fits are not accurate. The value of the models is that they allow one to determine, for almost arbitrary visual-discrimination tasks, what aspects of performance are accounted for by preneural factors. Furthermore, the models provide a precise metric of the discrimination information available at the receptors. This permits meaningful comparison of human performance across different tasks.

© 1985 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Physical limits of acuity and hyperacuity

Wilson S. Geisler
J. Opt. Soc. Am. A 1(7) 775-782 (1984)

Preneural limitations on letter identification in central and peripheral vision

Paul J. Beckmann and Gordon E. Legge
J. Opt. Soc. Am. A 19(12) 2349-2362 (2002)

Aging and the saturation of colors. 1. Colorimetric purity discrimination

James M. Kraft and John S. Werner
J. Opt. Soc. Am. A 16(2) 223-230 (1999)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (7)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (1)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (39)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription