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J Larimer

Publications and source records attributed to J Larimer.

7 recordsLinked to original sources
PubMed1993

Color appearance of filled-in backgrounds affects hue cancellation, but not detection thresholds.

A long-wavelength background can affect the appearance of an increment of light superimposed upon it in two ways. It can change the visual system's sensitivity to the increment, and it can change the appearance of the increment by directly adding redness to it. Through selective retinal-image stabilization, we evoked the filling-in phenomenon to change the appearance of 640- and 575-nm backgrounds. Either of these backgrounds could be made to appear red or yellow, depending upon whether it was viewed under stabilized or unstabilized conditions. When the appearance of the 640-nm background was altered by filling-in to appear less red, test probes superimposed upon it required less 540-nm component to achieve an equilibrium hue. Increment thresholds measured on the 640- and 575-nm backgrounds, however, did not change with the appearance of the backgrounds.

Adaptation, Ocular↗
PubMed1984

Color perception under chromatic adaptation: "supersensitivity" with dim backgrounds.

The amounts of 540 nm light and 660 nm light that when mixed result in a yellow (neither reddish nor greenish) percept remain in constant ratio, regardless of the total retinal illumance level of the mixture. A similar result holds if the mixture is superimposed upon a very dim 660 nm adapting field, except that a larger proportion of 540 nm light is required than in the dark (contrary to an effect of receptor desensitization, which would result in a smaller proportion of 540 nm light). Mixtures of 460 and 579 nm lights that give yellow/blue equilibrium percepts show the same effect: under very dim 579 nm adaptation, a larger proportion of 460 nm light is required than in the dark. These results cannot be accounted for by cone sensitivity reduction nor by a postreceptoral restoring effect; they reveal an additional mechanism of adaptation.

Adaptation, Ocular↗