PubMed · 5931469
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
W L Makous. 1966-05-20. Dermo-optical perception.. https://pubmed.ncbi.nlm.nih.gov/5931469/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
We describe two tests of the hypothesis that human judgments of the proximity of colors are consistent with a Euclidean geometry on color matching space. The first test uses proximity judgments to measure the angle between any two intersecting lines in color space. Pairwise estimates of the angles between three lines in a plane were made in order to test the additivity of angles. Three different color proximity tasks were considered. Additivity failed for each of the three proximity tasks. Secondly, we tested a prediction concerning the growth of the variability of judgments of similarity with the distance between the test and reference stimuli. The Euclidean hypothesis was also rejected by this test. The results concerning the growth of variability are consistent with the assumption that observers use a city-block metric when judging the proximity of colored lights.
On the basis of MacAdam's data, we have computed a psychophysical function which characterizes the transference of the colour information processed by the human visual system in the chromatic frequency domain. This function, obtained using chromatic-discrimination criteria, shows a cut-off frequency between 0.01375 and 0.02 c/nm, depending upon the colour-tolerance units adopted.
Color flashes on a steady-white background are classically used to isolate the response of the chromatic (color-opponent), as opposed to achromatic (luminance), channel in psychophysical investigations. The present study shows that pupillary responses evoked by such stimuli behave as if they are composed of functionally separable components. One component has a temporally transient waveform and has an action spectrum that is similar to the spectral sensitivity curve of the psychophysical chromatic channel. The present study discusses the possibility that the pupillary response is mediated by phasic (M-like) neurons and/or by tonic (P-like) neurons.