Hostname: page-component-7c8c6479df-7qhmt Total loading time: 0 Render date: 2024-03-28T14:45:09.406Z Has data issue: false hasContentIssue false

The gap effect is exaggerated in parafovea

Published online by Cambridge University Press:  06 September 2006

MARINA DANILOVA
Affiliation:
I.P. Pavlov Institute of Physiology, Laboratory of Visual Physiology, St. Petersburg, Russia
JOHN MOLLON
Affiliation:
Department of Experimental Psychology, Cambridge University, Cambridge, United Kingdom

Abstract

In central vision, the discrimination of colors lying on a tritan line is improved if a small gap is introduced between the two stimulus fields. Boynton et al. (1977) called this a “positive gap effect.” They found that the effect was weak or absent for discriminations based on the ratio of the signals of long-wave and middle-wave cones; and even for tritan stimuli, the gap effect was weakened when forced choice or brief durations were used. We here describe measurements of the gap effect in the parafovea. The stimuli were 1 deg of visual angle in width and were centered on an imaginary circle of radius 5 deg. They were brief (100 ms), and thresholds were measured with a spatial two-alternative forced choice. Under these conditions we find a clear gap effect, which is of similar magnitude for both the cardinal chromatic axes. It may be a chromatic analog of the crowding effect observed for parafoveal perception of form.

Type
PERIPHERAL VISUAL FIELD
Copyright
© 2006 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Bouma, H. (1970). Interaction effects in parafoveal letter recognition. Nature 226, 177178.Google Scholar
Boynton, R.M., Hayhoe, M.M., & MacLeod, D.I.A. (1977). The gap effect: Chromatic and achromatic visual discrimination as affected by field separation. Optica Acta 24, 159177.Google Scholar
Brindley, G.S. (1954). The summation areas of human colour-receptive mechanisms at increment threshold. Journal of Physiology 124, 400408.Google Scholar
Cottaris, N.P. & De Valois, R.L. (1998). Temporal dynamics of chromatic tuning in macaque primary visual cortex. Nature 395, 896900.Google Scholar
Dacey, D.M. & Lee, B.B. (1994). The “blue-on” opponent pathway in primate retina originates from a distinct bistratified ganglion cell type. Nature 367, 731735.Google Scholar
Dacey, D.M., Peterson, B.B., & Robinson, F.R. (2002). Identification of an S-cone opponent OFF pathway in the macaque monkey retina: Morphology, physiology and possible circuitry. Investigative Ophthalmology and Visual Science 43, E-Abstract 2983.Google Scholar
Danilova, M.V. & Mollon, J.D. (2003). Comparison at a distance. Perception 32, 395414.Google Scholar
Danilova, M.V. & Mollon, J.D. (2006). The comparison of spatially separated colours. Vision Research 46, 823836.Google Scholar
Eskew, R.T. (1989). The gap effect revisited: Slow changes in chromatic sensitivity as affected by luminance and chromatic borders. Vision Research 29, 717729.Google Scholar
Eskew, R.T. & Boynton, R.M. (1987). Effects of field area and configuration on chromatic and border discrimination. Vision Research 27, 18351844.Google Scholar
Eskew, R.T., Stromeyer, C.F., Picotte, C.J., & Kronauer, R.E. (1991). Detection uncertainty and the facilitation of chromatic detection by luminance contours. Journal of the Optical Society of America A 8, 394403.Google Scholar
Gouras, P. (1984). Colour vision. In Progress in Retinal Research, ed. Osbourne, N.N. & Chader, G.J., pp. 227261. Oxford: Pergamon.
Hess, R.F. & Jacobs, R.J. (1979). A preliminary report of acuity and contour interactions across the amblyope's visual field. Vision Research 19, 14031408.Google Scholar
Hilz, R.L., Huppmann, G., & Cavonius, C.R. (1974). Influence of luminance contrast on hue discrimination. Journal of the Optical Society of America 64, 763766.Google Scholar
Kosslyn, S.M., Ball, T.M., & Reiser, B.J. (1978). Visual images preserve metric spatial information: Evidence from studies of image scanning. Journal of Experimental Psychology 4, 4760.Google Scholar
Krauskopf, J., Williams, D.R., & Heeley, D.W. (1982). Cardinal directions of color space. Vision Research 22, 11231131.Google Scholar
Le Grand, Y. (1933). Sur la précision en photométrie visuelle. Revue d'optique théoretique et instrumentale 12, 145159.Google Scholar
Levi, D.M., Hariharan, S., & Klein, S.A. (2002). Suppressive and facilitatory spatial interactions in peripheral vision: Peripheral crowding is neither size invariant nor simple contrast masking. Journal of Vision 2, 167177.Google Scholar
Liebmann, S. (1927). Über das Verhalten farbiger Formen bei Helligkeitsgleichheit von Figur und Grund. Dissertation. Philosophischen Fakultät. Berlin, Friedrich-Wilhelms-Universität.
MacLeod, D.I.A. & Boynton, R.M. (1979). Chromaticity diagram showing cone excitation by stimuli of equal luminance. Journal of the Optical Society of America 69, 11831186.Google Scholar
Malkin, F. & Dinsdale, A. (1972). Colour discrimination studies in ceramic wall-tiles. In Color Metrics, ed. Vos, J.J., Friele, L.F.C. & Walraven, P.L., pp. 238253. Soesterberg: Institute for Perception TNO.
McKeefry, D.J., Parry, N.R.A., & Murray, I.J. (2003). Simple reaction times in color space: The influence of chromaticity, contrast, and cone opponency. Investigative Ophthalmology and Visual Science 44, 22672276.Google Scholar
Mollon, J.D., Estévez, O., & Cavonius, C.R. (1990). The two subsystems of colour vision and their rôles in wavelength discrimination. In Vision: Coding and Efficiency, ed. Blakemore, C., pp. 119131. Cambridge: Cambridge University Press.
Montag, E.D. (1997). Influence of boundary information on the perception of color. Journal of the Optical Society of America A 14, 9971006.Google Scholar
Parkes, L., Lund, J., Angelucci, A., Solomon, J.A., & Morgan, M. (2001). Compulsory averaging of crowded orientation signals in human vision. Nature Neuroscience 4, 739744.Google Scholar
Pelli, D.G., Palomares, M., & Majaj, N.J. (2004). Crowding is unlike ordinary masking: Distinguishing feature integration from detection. Journal of Vision 4, 11361169.Google Scholar
Regan, B.C. & Mollon, J.D. (1997). The relative salience of the cardinal axes of colour space in normal and anomalous trichromats. In Colour Vision Deficiencies, vol. 13, Cavonius, C.R., pp. 261270. Dordrecht: Kluwer.
Regan, B.C., Reffin, J.P., & Mollon, J.D. (1994). Luminance noise and the rapid determination of discrimination ellipses in colour deficiency. Vision Research 34, 12791299.Google Scholar
Rentschler, I. & Fiorentini, A. (1974). Meridional anisotropy of psychophysical spatial interactions. Vision Research 14, 14671473.Google Scholar
Sankeralli, M.J. & Mullen, K.T. (2001). Bipolar or rectified chromatic detection mechanisms. Visual Neuroscience 18, 127135.Google Scholar
Sharpe, L.T. & Wyszecki, G. (1976). Proximity factor in color-difference evaluations. Journal of the Optical Society of America 66, 4049.Google Scholar
Smith, V.C. & Pokorny, J. (1975). Spectral sensitivity of the foveal cone photopigments between 400 and 500 nm. Vision Research 15, 161171.Google Scholar
Smithson, H.E. & Mollon, J.D. (2004). Is the S-opponent chromatic sub-system sluggish? Vision Research 44, 29192929.Google Scholar
Stiles, W.S. (1949). Increment thresholds and the mechanisms of colour vision. Documenta Ophthalmologica 3, 138163.Google Scholar
Stockman, A. & Sharpe, L.T. (2000). The spectral sensitivities of the middle- and long-wavelength-sensitive cones derived from measurements in observers of known genotype. Vision Research 40, 17111737.Google Scholar
Tansley, B.W. & Boynton, R.M. (1976). A line, not a space, represents visual distinctness of borders formed by different colors. Science 191, 954957.Google Scholar
Traub, A.C. & Balinkin, I. (1961). Proximity factor in the Judd color difference formula. Journal of the Optical Society of America 51, 755760.Google Scholar
Vassilev, A., Mihaylova, M.S., Racheva, K., Zlatkova, M., & Anderson, R. (2003). Spatial summation of S-cone ON and OFF signals: Effects of retinal eccentricity. Vision Research 43, 28752884.Google Scholar
Walsh, J.W.T. (1958). Photometry. London: Constable.
West, M., Spillmann, L., Cavanagh, P., Mollon, J., & Hamlin, S. (1996). Susanne Liebmann in the critical zone. Perception 25, 14511495.Google Scholar
Wetherill, G.B. & Levitt, H. (1965). Sequential estimation of points on a psychometric function. British Journal of Mathematical and Statistical Psychology 18, 110.Google Scholar
Wolford, G. & Chambers, L. (1984). Contour interaction as a function of retinal eccentricity. Perception and Psychophysics 36, 457460.Google Scholar
Wyszecki, G. & Stiles, W.S. (1982). Color Science. New York: Wiley.