Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-04T21:26:28.628Z Has data issue: false hasContentIssue false
  • English
  • Français

Perceived length across the physiological blind spot

Published online by Cambridge University Press:  02 June 2009

Srimant P. Tripathy ,
Dennis M. Levi ,
Haluk Ogmen  and
Christine Harden
Srimant P. Tripathy
Affiliation:
College of Optometry, University of Houston, Houston
Dennis M. Levi
Affiliation:
College of Optometry, University of Houston, Houston
Haluk Ogmen
Affiliation:
College of Engineering, University of Houston, Houston
Christine Harden
Affiliation:
College of Optometry, University of Houston, Houston
Get access Rights & Permissions [Opens in a new window]

Abstract

Objects falling across the physiological blind spot appear “complete” despite the absence of photoreceptors. Completion of objects may occur across the blind spot because (1) the blind spot is filled in with the background (the associative explanation); (2) the opposite sides of the blind spot may be contiguously represented in the cortex (i.e. the blind spot is simply sewn up —the retinotopic explanation); or (3) the blind spot may be sewn up, with compensatory expansion occurring around the blind spot (the compensation explanation). These theories would predict no size distortions regardless of object size; constant size distortions regardless of object size; and distortions that depend on the size of the object, respectively. To evaluate these explanations, we measured size distortions at the blind spot. We measured length distortions at the blind spot using a criterion-free two-alternative forced-choice method with feedback. Observers compared the lengths of test bars presented across the blind spot with lengths of reference bars presented at the corresponding location in the fellow eye. Test bar lengths ranged from 7–14 deg. Reference bar lengths were in the range of ±3 deg of test bar length. From the observers' responses the perceived length of each bar at the blind spot was estimated. Estimates of the precision of length discrimination at the blind spot were also obtained. Our results were consistent with the associative explanation. In all seven observers, length distortions at the blind spot were smaller than 1 deg (<20% of the vertical height of the blind spot) for all bar lengths tested. For bars that were presented across the blind spot, the precision with which observers could discriminate length was comparable to that of normal periphery (Weber fraction ≈20%). Both the veridicality and precision of perceived length are preserved around the blind spot.

Keywords

Blind spotFilling-inLength distortionsOptic diskScotoma
Type
Research Articles
Information
Visual Neuroscience , Volume 12 , Issue 2 , March 1995 , pp. 385 - 402
Copyright
Copyright © Cambridge University Press 1995

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

Andrews, P.R. & Campbell, F.W. (1991). Images at the blind spot. Nature 353, 308.CrossRefGoogle ScholarPubMed
Barbeito, R., Levi, D.M., Klein, S. & Loshin, D. (1985). Stereo-deficients and stereoblinds cannot make utrocular discriminations. Vision Research 9, 1345–1348.Google Scholar
Beck, J. & Halloran, T. (1985). Effects of spatial separation and retinal eccentricity on two-dot Vernier acuity. Vision Research 25, 1105–1111.Google Scholar
Bender, M.B. & Teuber, H.L. (1946). Phenomena of fluctuation, extinction, and completion in visual perception. Archives of Neurology and Psychiatry 55, 627–658.CrossRefGoogle ScholarPubMed
Boring, E.G. (1943). The moon illusion. American Journal of Physics 11, 55–60.CrossRefGoogle Scholar
Brown, R.J. & Thurmond, J.B. (1993). Preattentive and cognitive effects on perceptual completion at the blind spot. Perception and Psychophysics 53, 200–209.Google Scholar
Callaway, E.M. & Katz, L.C. (1990). Emergence and refinement of clustered horizontal connections in cat striate cortex. Journal of Neuroscience 10, 1134–1153.CrossRefGoogle ScholarPubMed
Chino, Y.M., Kaas, J.H., Smith, E.L. III, Langston, A.L. & Cheng, H. (1992). Rapid reorganization of cortical maps in adult cats following restricted deafferentation in retina. Vision Research 32, 789–796.CrossRefGoogle ScholarPubMed
Dennett, D.C. (1991). Consciousness Explained. Boston, Massachusetts: Little, Brown & Co.Google Scholar
Enoch, J., Goldmann, H. & Sunga, R. (1969). The ability to distinguish which eye was stimulated by light. Investigative Ophthalmology and Visual Science 8, 317–331.Google ScholarPubMed
Ferree, C.E. & Rand, G. (1912). The spatial values of the visual field immediately surrounding the blind spot and the question of the associative filling in of the blind spot. American Journal of Physiology 29, 398–412.Google Scholar
Fiorani, M. Jr., Rosa, M.G.P., Gattass, R. & Rocha-Miranda, C.E. (1992). Dynamic surrounds of receptive fields in primate striate cortex: A physiological basis for perceptual completion? Proceedings of the National Academy of Sciences of the U.S.A. 89, 8547–8551.Google Scholar
Gattass, R., Fiorani, M. Jr., Rosa, M.G.P., Pinon, M.C.G.P., De Sousa, A.P.B. & Soares, J.G.M. (1992). Visual responses outside the classical receptive field in primate striate cortex: A possible correlate of perceptual completion. In The Visual System from Genesis to Maturity (pp. 233–244). ed. Lent, R., Boston, Massachusetts: Birkhahser.CrossRefGoogle Scholar
Gerrits, H.J.M. & Timmerman, G.J.M.E.N. (1969). The filling-in process in patients with retinal scotomata. Vision Research 9, 439–442.Google Scholar
Gilbert, C.D. (1992). Horizontal integration and cortical dynamics. Neuron 9, 1–13.CrossRefGoogle ScholarPubMed
Gilbert, C.D. & Wiesel, T.N. (1979). Morphology and intracortical projections of functionally identified neurones in cat visual cortex. Nature 280, 120–125.CrossRefGoogle ScholarPubMed
Gilbert, C.D. & Wiesel, T.N. (1983). Clustered intrinsic connections in cat visual cortex. Journal of Neuroscience 3, 1116–1133.Google Scholar
Gilbert, C.D. & Wiesel, T.N. (1989). Columnar specificity of intrinsic horizontal and corticocortical connections in cat visual cortex. Journal of Neuroscience 9, 2432–2442.Google Scholar
Gilbert, C.D. & Wiesel, T.N. (1990). The influence of contextual stimuli on the orientation selectivity of cells in primary visual cortex of the cat. Vision Research 30, 1689–1701.Google Scholar
Helson, H. (1929). The effects of direct stimulation of the blind spot. American Journal of Psychology 41, 345–397.Google Scholar
Hirsch, J.A. & Gilbert, C.D. (1991). Synaptic physiology of horizontal connections in the cat's visual cortex. Journal of Neuroscience 11, 1800–1809.CrossRefGoogle ScholarPubMed
Horton, J.C. (1984). Cytochrome oxidase patches: A new cytoarchi-tectonic feature of monkey visual cortex. Philosophical Transactions of the Royal Society (London) 304, 199–253.Google ScholarPubMed
Kaas, J.H., Krubitzer, L.A., Chino, Y.M., Langston, A.L., Polley, E.H. & Blair, N. (1990). Reorganization of retinotopic cortical maps in adult mammals after lesions of the retina. Science 248, 229–231.CrossRefGoogle ScholarPubMed
Kawabata, N. (1982). Visual information processing at the blind spot. Perceptual and Motor Skills 55, 95–104.CrossRefGoogle ScholarPubMed
Kawabata, N. (1983). Global interactions in perceptual completion at the blind spot. Vision Research 23, 275–279.CrossRefGoogle ScholarPubMed
Kawabata, N. (1984). Perception at the blind spot and similarity grouping. Perception and Psychophysics 36, 151–158.CrossRefGoogle ScholarPubMed
Kennedy, C., Des Rosiers, M.H., Jehle, J.W., Reivich, M., Sharpe, F. & Sokoloff, L. (1975). Mapping of functional neural pathways by autoradiographic survey of local metabolic rate with deoxyglucose. Science 187, 850–53.Google Scholar
Kennedy, C., Des Rosiers, M.H., Sakurada, O., Shinohara, O., Reivich, M., Jehle, J.W. & Sokoloff, L. (1976). Metabolic mapping of the primary visual system of the monkey by means of the autoradiographic [14C]deoxyglucose technique. Proceedings of the National Academy of Sciences of the U.S.A. 73, 4230–4234.Google Scholar
Kooi, F.L., Toet, A., Tripathy, S.P. & Levi, D.M. (1994). The effect of similarity and duration on spatial interaction in peripheral vision. Spatial Vision 8, 255–279.Google ScholarPubMed
Lashley, K.S. (1941). Patterns of cerebral integration indicated by the scotomas of migraine. Archives of Neurology and Psychiatry 46, 331–339.Google Scholar
LeVay, S., Connolly, M., Houde, J. & Van Essen, D.C. (1985). The complete pattern of ocular dominance stripes in the striate cortex and visual field of the macaque monkey. Journal of Neuroscience 5, 486–501.Google Scholar
Levi, D.M. & Klein, S.A. (1990). The role of separation and eccentricity in encoding position. Vision Research 30, 557–585.Google Scholar
Martin, K.A.C. & Whitteridge, D. (1984). Form, function and intracortical projections of spiny neurones in the striate visual cortex of the cat. Journal of Physiology 353, 463–504.Google Scholar
Nazir, T.A. (1992). Effects of lateral masking and spatial precueing on gap-resolution in central and peripheral vision. Vision Research 32, 771–777.Google Scholar
Ono, H. & Barbeito, R. (1985). Utrocular discrimination is not sufficient for utrocular identification. Vision Research 25, 289–299.Google Scholar
Peterhans, E. & Von Der Heydt, R. (1989). Mechanisms of contour perception in monkey visual cortex: 2. Contours bridging gaps. Journal of Neuroscience 9, 1749–1763.Google Scholar
Plug, C. & Ross, H.E. (1994). The natural moon illusion: A multifactor angular account. Perception 23, 321–333.CrossRefGoogle ScholarPubMed
Ramachandran, V.S. (1992 a). Filling in gaps in perception: Part I. Current Directions in Psychological Science 1, 199–205.Google Scholar
Ramachandran, V.S. (1992 b). Blind spots. Scientific American 266, 86–91.Google Scholar
Ramachandran, V.S. (1993). Filling in gaps in perception: Part II. Current Directions in Psychological Science 2, 56–65.Google Scholar
Ramachandran, V.S. & Gregory, R.L. (1991). Perceptual filling in of artificially induced scotomas in human vision. Nature 350, 699–702.CrossRefGoogle ScholarPubMed
Ramachandran, V.S., Gregory, R.L. & Aiken, W. (1993). Perceptual fading of visual texture borders. Vision Research 33, 717–721.CrossRefGoogle ScholarPubMed
Rockland, K.S. & Lund, J.S. (1983). Intrinsic laminar lattice connections in primate visual cortex. Journal of Comparative Neurology 216, 303–318.Google Scholar
Schuchard, R.A. (1993). Validity and interpretation of Amsler grid reports. Archives of Ophthalmology 111, 776–780.Google Scholar
Sears, C.R. & Mikaelian, H.H. (1989). Explorations of perceptual functioning surrounding the optic disk. Canadian Psychology 30(2a), 408.Google Scholar
Sergent, J. (1988). An investigation into perceptual completion in blind areas of the visual field. Brain 111, 347–373.CrossRefGoogle ScholarPubMed
Sullivan, G.D., Oatley, K. & Sutherland, N.S. (1972). Vernier acuity as effected by target length and separation. Perception and Psychophysics 12, 438–444.CrossRefGoogle Scholar
Tripathy, S.P. & Levi, D.M. (1993). Perceptual distortions and cortical binocular interactions around the blind spot. Investigative Ophthalmology and Visual Science (Suppl.) 34, 794.Google Scholar
Tripathy, S.P. & Levi, D.M. (1994). Long-range dichoptic interaction in the human visual cortex in the region corresponding to the blind spot. Vision Research 34, 1127–1138.Google Scholar
Tripathy, S.P., Levi, D.M. & Ogmen, H. (1994 a). 2-dot alignment across the physiological blind spot. Investigative Ophthalmology and Visual Science (Suppl.) 35/4, 1256.Google Scholar
Tripathy, S.P., Levi, D.M. & Ogmen, H. (1994 b). Length and separation distortions do not correspond around the blind spot. Vision Science and its Applications, 1994 Technical Digest Series, Vol. 2, (Optical Society of America, Washington, DC, 1994), pp. 155–158.Google Scholar
Ts'o, D.Y., Gilbert, C.D. & Wiesel, T.N. (1986). Relationships between horizontal interactions and functional architecture in cat striate cortex as revealed by cross-correlation analysis. Journal of Neuroscience 6(4), 1160–1170.Google Scholar
Von Der Heydt, R. & Peterhans, E. (1989). Mechanisms of contour perception in monkey visual cortex. 1. Lines of pattern discontinuity. Journal of Neuroscience 9, 1731–1748.CrossRefGoogle Scholar
Von Der Heydt, R., Peterhans, E. & Baumgartner, G. (1984). Illusory contours and cortical neuron responses. Science 224, 1260–1262.CrossRefGoogle ScholarPubMed
Walls, G.L. (1954). The filling-in process. American Journal of Optometry, 3, 329–341.Google Scholar