Abstract
W. S. Stiles, in a series of classic studies (Stiles, 1939; 1949; 1953; 1959; 1978) developed the two-color increment threshold technique, and applied it to the analysis of the mechanisms of color vision. In Stiles’s procedure an observer is adapted successively to each of a series of increasingly intense exposures of a large field of one wavelength (μ), and the threshold is measured for a relatively small and brief test of another wavelength (λ) presented in the center of the adapting field. The resulting data are plotted as an increment threshold curve or threshold-vs. intensity (t.v.i.) curve, giving log Uλ, the logarithm of the threshold intensity as a function of log Wμ, the logarithm of the background intensity. Even if the test target is confined to the fovea, the full increment threshold curve usually is found to be composed of two or more distinct component regions or “branches”, much as parafoveal dark adaptation curves normally comprise two distinct component regions.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Augenstein, E.J. & Pugh, Jr., E.N. (1977). The dynamic behavior of Stiles’s π1 colour mechanism: further evidence for two sites of adaptation. J. Physiol., 272, 247–281.
Friedman, L.J. (1983). Cone antagonism along visual pathways of red/green dichromats. Ph.D. Thesis, Univ. of Michigan.
Friedman, L.J., Thornton, J.E, & Pugh, Jr., E.N. (1984). Cone antagonism along visual pathways of red/green dichromats. Submitted.
Friedman, L.J., Yim, P. & Pugh, Jr., E.N. (1984). Temporal integration of the π1/π3 pathway in normal and dichromatic vision. Vision Res., in press.
Hurvich, L.M. & Jameson, D. (1957). An opponent process theory of color vision. Psychol. Rev., 64, 384–404.
Kranda, K. & King-Smith, P.E. (1979). Detection of colored stimuli by independent linear systems. Vision Res., 19, 733–745.
Krantz, D.H. (1975). Color measurement and color theory. I. Representation theorem for Grassmann structures. J. Math. Psych., 12, 283–303.
Mollon, J.D. & Polden, P.G. (1977a). An anomaly in the response of the eye to light of short wavelengths. Phil. Trans. Roy. Soc. Lond., 278, 207–240.
Mollon, J.D. & Polden, P.G. (1977b). Further anomalies of the blue mechanism. Invest. Ophthal. Vis. Sci., ARVO Supplement.
Pugh, Jr., E.N. (1976). The nature of the TTI mechanism of W.S. Stiles. J. Physiol., 257, 713–747.
Pugh, Jr., E.N. & Larimer, J. (1980). Test of the identity of the site of blue/yellow hue cancellation and the site of chromatic antagonism in the π1 pathway. Vision Res., 20, 779–788.
Pugh, Jr., E.N. & Mollon, J.D. (1979). A theory of the π1 and π3 color mechanisms of W.S. Stiles. Vision Res., 19, 293–312.
Sperling, H.G. & Harwerth, R.S. (1971). Red-green cone interactions in the increment threshold spectral sensitivity of primates. Science, 172, 180–184.
Stiles, W.S. (1939). The directional sensitivity of the retina and the spectral sensitivities of the rods and cones. Proc. Roy. Soc. B., 127, 64–105.
Stiles, W.S. (1949). Increment thresholds and the mechanisms of colour vision. Doc. Ophthal., 3, 138–163.
Stiles, W.S. (1953). Further studies of visual mechanisms by the two-colour threshold method. Coloq. Probl. Opt. Vis. (U.I.P.A.P., Madrid), 1, 65–103.
Stiles, W.S. (1959). Color vision: the approach through increment-threshold sensitivity. Proc. Natl. Acad. Sci., 45, 100–114.
Stiles, W.S. (1967). Mechanism concepts in colour theory. J. of the Colour Group, 105–123.
Stiles, W.S. (1978). Mechanisms of Colour Vision. Academic Press, New York.
Thornton, J.E. & Pugh, Jr., E.N. (1982). Threshold inhibition in the yellow/blue pathway. Invest. Ophthal. Vis. Scie., 22, 18, (ARVO Supplement).
Thornton, J.E. & Pugh, Jr., E.N. (1983a). Red/green color opponency at detection threshold. Science, 219, 191–193.
Thornton, J.E. & Pugh, Jr., E.N. (1983b). Relationships of opponent-colours cancellation measures to cone-antagonistic signals deduced from increment threshold data. In Color Vision: Physiology and Psychophysics. (eds. J.D. Mollon and L.T. Sharpe). Academic Press, New York. 361–373.
Thornton, J.E. & Pugh, Jr., E.N. (1984). Blue/yellow color opponency at increment threshold. In preparation.
Wisowaty, J.J. & Boynton, R.M. (1980). Temporal modulation sensitivity of the blue mechanism: measurements made without chromatic adaptation. Vision Res., 20, 895–909.
Wyszecki, G. & Stiles, W.S. (1982). Color Science (2nd edition). Wiley, New York.
Yim, P. (1983). The temporal characteristics of a short-wavelength sensitive pathway. Ph.D. Thesis, Univ. of Pennsylvania.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Copyright information
© 1985 The Wenner-Gren Center
About this chapter
Cite this chapter
Pugh, E.N., Thornton, J.E., Friedman, L.J., Yim, M.H. (1985). Stile’s π 1 and π 2 Colour Mechanisms: Isolation of a Blue/Yellow Pathway in Normals and Dichromats. In: Ottoson, D., Zeki, S. (eds) Central and Peripheral Mechanisms of Colour Vision. Wenner-Gren Center International Symposium Series. Palgrave Macmillan, London. https://doi.org/10.1007/978-1-349-08020-5_8
Download citation
DOI: https://doi.org/10.1007/978-1-349-08020-5_8
Publisher Name: Palgrave Macmillan, London
Print ISBN: 978-1-349-08022-9
Online ISBN: 978-1-349-08020-5
eBook Packages: Biomedical and Life SciencesBiomedical and Life Sciences (R0)