Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-24T02:25:05.919Z Has data issue: false hasContentIssue false

Inferred retinal mechanisms mediating illusory distortions

Published online by Cambridge University Press:  05 April 2005

MARCO J.H. PUTS
Affiliation:
Visual Science Laboratories, University of Chicago, Chicago
JOEL POKORNY
Affiliation:
Visual Science Laboratories, University of Chicago, Chicago
VIVIANNE C. SMITH
Affiliation:
Visual Science Laboratories, University of Chicago, Chicago

Abstract

The Zoellner illusion is a geometric distortion occurring when nonorthogonal inducing lines appear to tilt veridically parallel bars. The retinal pathways contributing to such illusions are unknown. The goal of this experiment was to investigate the retinal origin of the illusion. This was accomplished by determining the contrast gain for illusion thresholds. The magnocellular (MC-) and parvocellular (PC-) pathways exhibit different contrast gains, and this difference can be used psychophysically to identify the pathway. The stimulus pattern was four vertical bars with a series of inducing lines. The bars were always 5% higher in contrast than the inducing bars. The pattern was presented on a larger pedestal. Two paradigms were used. In the pulsed-pedestal paradigm, the observer adapted to the background and the pedestal and pattern were presented together as a brief pulse. In the steady-pedestal paradigm, the observer adapted to the continuously presented pedestal and the pattern appeared as a brief pulse. The contrast between the pedestal and the pattern was varied to obtain thresholds for two criteria: perceiving the directions of the inner inducing lines, and perceiving the distortion of the bars. The results for both criteria were similar in shape, but displaced in sensitivity. Detection of the directions of the inner inducing lines was 0.16–0.29 log unit more sensitive than perception of the illusion. The data for the pulsed-pedestal paradigm depended on the contrast between the pedestal and the pattern and produced a shallow V-shape. These results were associated with mediation in the PC-pathway. The data for the steady-pedestal paradigm depended on the pedestal luminance in a linear relation and showed similar sensitivity to the data for the pulsed-pedestal paradigm. Perception of the illusion required 10–15% Weber contrast.

Type
Research Article
Copyright
© 2004 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

Dobkins, K.R. & Albright, T.D. (1995). Behavioral and neural effects of chromatic isoluminance in the primate visual motion system. Visual Neuroscience 12(2), 321332.Google Scholar
Fisher, G.H. (1968). The Frameworks for Perceptual Localization. Newcastle upon Tyne: University of Newcastle upon Tyne.
Gregory, R.L. (1977). Vision with isoluminant colour contrast: 1. A projection technique and observations. Perception 6, 113119.Google Scholar
Gregory, R.L. (1997). Eye and Brain: The Psychology of Seeing (5th edition). New Jersey: Princeton University Press.
Kaiser, P.K., Lee, B.B., Martin, P.R., & Valberg, A. (1990). The physiological basis of the minimally distinct border demonstrated in the ganglion cells of the macaque retina. Journal of Physiology (London) 422, 153183.Google Scholar
Kaplan, E. & Shapley, R.M. (1982). X and Y cells in the lateral geniculate nucleus of macaque monkeys. Journal of Physiology 330, 125143.Google Scholar
Lee, B.B., Martin, P.R., & Valberg, A. (1989). Nonlinear summation of M- and L-cone inputs to phasic retinal ganglion cells of the macaque. Journal of Neuroscience 9, 14331442.Google Scholar
Lehman, A. (1904). Die irradiation als Ursache geometrisch-optischer Täusungen. Pflügers Archiv 103, 84106.CrossRefGoogle Scholar
Leonova, A., Pokorny, J., & Smith, V.C. (2003). Spatial frequency processing in inferred PC- and MC-pathways. Vision Research 43, 21332139.Google Scholar
Li, C.Y. & Guo, K. (1995). Measurements of geometric illusions, illusory contours and stereo-depth at luminance and colour contrast. Vision Research 35, 17131720.CrossRefGoogle Scholar
Liebmann, S. (1927). Über das Verhalten farbiger Formen bei Helligkeitsgleichheit von Figur und Grund. Psychologische Forschung 9, 300353. (English translation: West, M., Spillmann, L., Cavanagh, P., Mollon, J. & Hamlin, S. (1996). Susanne Liebmann in the critical zone. Perception 25, 1451–1495).Google Scholar
Livingstone, M.S. & Hubel, D.H. (1987). Psychophysical evidence for separate channels for the perception of form, color, motion and depth. Journal of Neuroscience 7, 34163468.Google Scholar
Mollon, J.D. (1982). Color vision. Annual Review of Psychology 33, 4185.Google Scholar
Pokorny, J. & Smith, V.C. (1997). Psychophysical signatures associated with magnocellular and parvocellular pathway contrast gain. Journal of the Optical Society of America A 14, 24772486.Google Scholar
Pokorny, J., Sun, V.C.W., & Smith, V.C. (2003). Temporal dynamics of early light adaptation. Journal of Vision 3, 423431. (http://journalofvision.org/3/6/3/).Google Scholar
Schiller, P.H. & Colby, C.L. (1983). The responses of single cells in the lateral geniculate nucleus of the rhesus monkey to color and luminance contrast. Vision Research 23, 16311641.Google Scholar
Smith, V.C. & Pokorny, J. (2003). Psychophysical correlates of parvo- and magnocellular function. In Normal and Defective Colour Vision, ed. Mollon, J., Pokorny, J. & Knoblauch, K., pp. 91107. Oxford, USA: Oxford University Press.
Smith, V.C., Sun, V.C., & Pokorny, J. (2001). Pulse and steady-pedestal contrast discrimination: Effect of spatial parameters. Vision Research 41, 20792088.Google Scholar
Snippe, H.P. (1998). Psychophysical signatures associated with magnocellular and parvocellular pathway contrast gain: Comment. Journal of the Optical Society of America A 15, 24402442.CrossRefGoogle Scholar
Wade, N. (1982). The Art and Science of Visual Illusions. London, UK: Routledge & Kegan Paul.
Westheimer, G., Brincat, S., & Wehrhahn, C. (1999). Contrast dependency of foveal spatial functions: Orientation, vernier, separation, blur and displacement discrimination and the tilt and Poggendorff illusions. Vision Research 39, 16311639.Google Scholar