The predominance of rivalrous targets is affected by surrounding context when stimuli rival in orientation, motion or color. This study investigated the influence of chromatic context on binocular color rivalry. The predominance of rivalrous chromatic targets was measured in various surrounding contexts. The first experiment showed that a chromatic surround's influence was stronger when the sur...

We have revealed a new role for colour vision in visual scene analysis: colour vision facilitates shadow identification. Shadows are important features of the visual scene, providing information about the shape, depth, and movement of objects. To be useful for perception, however, shadows must be distinguished from other types of luminance variation, principally the variation in object reflecta...

Abstract In this paper we obtain the explicit formulas for chromatic polynomials of cacti. From the results relating to cacti we deduce the analogous formulas for the chromatic polynomials of n–gon–trees. Besides, we characterize unicyclic graphs by their chromatic polynomials. We also show that the so–called clique–forest–like graphs are chromatically equivalent.

Characterization of two genetically distinct groups of marine Synechococcus sp. strains shows that one, but not the other, increases its phycourobilin/phycoerythrobilin chromophore ratio when growing in blue light. This ability of at least some marine Synechococcus strains to chromatically adapt may help explain their greater abundance in particular ocean environments than cyanobacteria of the ...

A class of graphs called generalized ladder graphs is defined. A sufficient condition for pairs of these graphs to be chromatically equivalent is proven. In addition a formula for the chromatic polynomial of a graph of this type is proven. Finally, the chromatic polynomials of special cases of these graphs are explicitly computed.

Neurons in the middle temporal visual area (MT) of macaque cerebral cortex are highly selective for the direction of motion but not the color of a moving stimulus. Recent experiments have shown, however, that the directional selectivity of many MT neurons persists even when a moving stimulus is defined solely by chromatic variation (Charles and Logothetis, 1989; Saito et al., 1989; Dobkins and ...