Abstract
Spectral luminosity functions were determined by measuring the radiation power of monochromatic test lights of 2° and 10° in diameter during exposure to white light of 30, 000 td. Criterion was (a) the achromatic threshold, (b) the chromatic threshold, (c) a small constant amplitude in the visually evoked cortical potential (VECP). With a test light duration of 10 ms the achromatic threshold exhibited a spectral luminosity function similar in shape to the CIE Vλ-curve, except for a slightly increased sensitivity in the shortwave region of the spectrum. Using the chromatic threshold as index, a general loss of sensitivity was found, i.e. a small (0.1 log unit) photochromatic interval in the longwave and a large (0.5 log unit) photochromatic interval in the middle and shortwave region of the spectrum relative to the achromatic threshold sensitivity. The spectral luminosity function obtained, using the VECP threshold amplitude criterion as index, was different from that using sensory criteria and exhibited an increased sensitivity near 600 nm and a loss in the green part of the spectrum.
With a test light duration of 400 ms no photochromatic interval was observed; both the sensory and the VECP luminosity function exhibited an increased sensitivity in the longwave part of the spectrum, resulting in a three-peak function. With stimulus diameter of 2°, spatial summation was found only in the function determined by the VECP with 10 ms stimulus duration.
The double sensitivity peak in the longwave region obtained with 400 ms stimulus duration or with suprathreshold stimulus intensity could be described by a linear subtraction of the predominant red and green sensitive fundamental function (R and G resp., defined in VECP experiments). The curve obtained by sensory threshold measurements with 10 ms stimulus duration, however, could be described only by linear addition of R and G functions. This indicates that under strong white adaptation the establishing of color opponency processes as determined by threshold measurements is evidently influenced by stimulus duration.
If we assume that just visible flashes of duration longer than the maximum integration time are a special kind of suprathreshold stimulation, the color opponent system would be activated if a certain number of quanta above the threshold is exceeded, whether the suprathreshold condition is defined by the critical stimulus duration or stimulus intensity.
Measurements by some authors of the spectral sensitivity functions by means of the visually evoked cortical potential (VECP) indicated some dissimilarities to the functions determined psychophysically (Armington, 1964; Cavonius, 1965; Cigánek & Ingvar, 1969; Siegfried, 1971), while other investigators found a close resemblance between sensory and electrical measurements (Regan, 1970; Adachi-Usami et al., 1974; Zrenner et al. 1975). The differences may be based upon the different response criteria chosen or upon different conditions of stimulation. Since the experiments of Svaetichin & MacNichol (1958) on lower vertebrates and of De Valois et al. (1966) and Wiesel & Hubel (1966) on mammals, the existence of two types of neural units associated with cone vision has been well established: (a) color opponent cells which show inhibitory effects in response to one wavelength region but excitatory effects to another, and (b) non-opponent cells which indicate some degree of summation. Recently, Padmos & Norren (1975) found indications for color opponency also by recording graded potentials in the visual cortex of monkeys. Using microelectrodes in monkey cortex, Gouras (1974) found some cells which showed color opponency at threshold, while others required suprathreshold stimuli for its manifestation.
The present study demonstrates that experiments using intense white adaptation exhibit color opponency also in the gross potential of the visual cortex of man. The measurement of spectral sensitivity functions by sensory thresholds compared with those using a VECP amplitude criterion reveals the important role of stimulus duration and suprathreshold stimulation for establishing the interaction of color opponent mechanisms. This interaction can be described mathematically by a simple procedure using linear subtraction resp. addition of VECP fundamental spectral sensitivity functions obtained under conditions of strong chromatic adaptation (Zrenner & Kojima, 1977).
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References
Adachi-Usami, E., J. Heck, V. Gavriysky & F.-J. Kellermann: Spectral sensitivity function determined by the visually evoked cortical potential in several classes of colour deficiency (cone monochromatism, rod monochromatism, protanopia, deuteranopia). Ophthal, Res. 6, 273–290 (1974).
Armington, J. C.: Relations between electrorctinograms and occipital potentials elicited by flickering stimuli. Proc. 2nd ISCERG Symp. Amsterdam 1963, Doc. Ophthal. 18, 194–206 (1964).
Barlow, H. B.: Temporal and spatial summation in human vision at different background intensities. J. Physiol. 141, 337–350 (1958).
Bouman, M. A. & P. L. Walraven: Some color naming experiments for red and green monochromatic lights. J. opt. Soc. Am. 47, 834–839 (1957).
Bouman, M. A. & P. L. Walraven: On threshold mechanisms for achromatic and chromatic vision. Acta Physiol. 36, 178–189 (1972).
Cavonius, C. R.: Evoked response of the human visual cortex: Spectral sensitivity. Psychon. Sci. 2, 185–186 (1965).
CIE: International Lighting Vocabulary, 3rd Ed., CIE Publication No. 17, Paris 1970.
Ciganek, L. & D. H. Ingvar: Colour specific features of visual cortical responses in man evoked by monochromatic flashes. Acta physiol. scand. 76, 82–92 (1969).
De Valois, R. L., I. Abramov & G. H. Jacobs: Analysis of response patterns of LGN cells. J. opt. Soc. Am. 56, 966–977 (1966).
Dixon, W. J.: The up-and-down methode for small samples. J. Am. Statist. Ass. 60, 967–978 (1965).
Eichengreen, J. M.: Separate chromatic thresholds for binary hue stimuli. Vision Res. 16, 321–322 (1916).
Gouras, P.: Opponent colour cells in different layers of foveal striate cortex. J. Physiol. 238, 583–602 (1974).
Gouras, P. & P. Padmos: Identification of cone mechanisms in graded responses of foveal striate cortex. J. Physiol. 238, 569–581 (1974).
Graham, C. H. & Y. Hsia: Saturation and the foveal achromatic interval. J. opt. Soc. Am. 59, 993–997 (1969).
Ikeda, M. & R. M. Boynton: Effect of test-flash duration upon the spectral sensitivity of the eye. J. opt. Soc. Am. 52, 697–699 (1962).
Kellermann, E.-J. & E. Adachi-Usami: Spectral sensitivities of colour mechanisms isolated by the human visual evoked response. Ophthal. Res. 4, 199–210 (1972/73).
King-Smith, P. E.: Visual detection analysed in terms of luminance and chromatic signals. Nature 255, 69–70 (1975).
Krüger, J. & P. Gouras: Many cells in visual cortex use wavelength to detect borders and convey information about colour. Exp. Brain Res. (in press, personal communication).
Monroe, M. M.: The energy value of the minimum visible chromatic and achromatic for different wave-lengths of the spectrum. Psychol. Rev. Publ. 34, Psychol. Monographs No. 158 (1924).
Padmos, P. & V. Graf: Colour vision in rhesus monkey, studied with subdurally im planted cortical electrodes. 11th ISCERG Symp. Bad Nauheim 1973, Doc. Ophthal. Proc. Series 4, 307–314 (1974).
Padmos, P. & D. V. Norren: Increment spectral sensitivity and colour discrimination in the primate, studied by means of graded potentials from the striate cortex. Vision Res. 15, 1103–1113 (1915).
Regan, D: Objective method of measuring the relative spectral luminosity curve in man. J. opt. Soc. Am. 60, 856–859 (1970).
Regan, D. & C. W. Tyler: Temporal summation and its limit for wavelength changes: An analog of Bloch’s law of color vision. J. opt. Soc. Am 61, 1414–1421 (1971).
Siegfried, J. B.: Spectral sensitivity of human visual evoked cortical potentials: A new method and a comparison with psychophysical data. Vision Res. 11, 405–417 (1971).
Sperling, H. G. & R. S. Harwerth: Red-green cone interactions in the increment-threshold spectral sensitivity of primates. Science 172, 180–184 (1971).
Stiles, W. S.: Colour vision: The approach through increment threshold sensitivity. Proc. Nat. Acad. Sci. USA 45, 100–114 (1959).
Svaetichin, G. & E. E. MacNichol, Jr.: Retinal mechanisms for chromatic and achromatic vision. Ann. N. Y. Acad. Sci. 74, 385–404 (1958).
Tittarelli, R.: Photochromatic interval as a function of spot size: A controversy. Atti londazione G. Ronchi 22, No. 3 (1967).
Wald, G.: The receptors of human color vision. Science 145, 1007–1017 (1964).
Wiesel, T. N. & D. H. Hubel: Spatial and chromatic interactions in the lateral geniculate body of the rhesus monkey. J. Neurophysiol. 29, 1115–1156 (1966).
Zrenner, E. & M. Kojima: Colour vision mechanisms isolated by chromatic adaptation in normals and dichromats as detected by the visually evoked cortical potential (VECP). 13th ISCFRG Symp. Israel, 1975. Doc. Ophthal. Proc. Series 11, 115–121 (1977).
Zrenner, E. & M. Kojima: The visually evoked cortical potential (VECP) in dichromats. Colour Vision Deficiences III. Int. Symp., Amsterdam 1975. Mod. Probl. Ophthal. 17, 241–246 (1916).
Zrenner, E., V. Gavriysky & E.-J. Kellermann: Further studies on the colour mechanisms in the human visually evoked cortical potential (VFCP) isolated by selective chromatic adaptation. Proc. 2nd ERG Conf. Wroclaw, Vol. 1, 7–16 (1975).
Zrenner, E., M. Kojima & E. Jankov: Untersuchung ders Farbsinns mit der Methode der visuell evozierten cortiealen Potentiale (VFCP). Ber. Dtsch. Ophthal. Ges. 74, 717–722 (1977).
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Zrenner, E. (1977). Influence of Stimulus Duration and Area on the Spectral Luminosity Function as Determined by Sensory and VECP Measurements. In: Lawwill, T. (eds) ERG, VER and Psychophysics. Documenta Ophthalmologica, vol 13. Springer, Dordrecht. https://doi.org/10.1007/978-94-010-1312-3_4
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DOI: https://doi.org/10.1007/978-94-010-1312-3_4
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