Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-25T05:46:08.024Z Has data issue: false hasContentIssue false

Behavioral evidence of filling-in at the blind spot of the monkey

Published online by Cambridge University Press:  02 June 2009

Hidehiko Komatsu
Affiliation:
Neuroscience Section, Electrotechnical Laboratory, 1-1 Umezono, Tsukuba, Ibaraki, 305, Japan
Ikuya Murakami
Affiliation:
Department of Psychology, Division of Humanities, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113, Japan

Abstract

In human subjects, the blind spot is perceptually filled-in by color and brightness from the surrounding visual field. The present behavioral study examined the occurrence of color filling-in at the blind spot in monkeys. First, the location of the blind spot was determined using a monocular saccade task. The blind spots were located on the horizontal meridian at approximately 15–17 deg from the fixation point in the temporal visual field. Then, filling-in at the blind spot was tested by determining if the monkey could discriminate between an annulus presented on the blind spot and a homogeneous disk in the normal visual field. In this task, the monkey was required to make a saccade to a homogeneous disk of the same color and size as an annulus presented simultaneously in the opposite field. Both stimuli were large enough to cover the blind spot and the inner circle of the annulus was confined inside the blind spot. All four monkeys tested performed this task correctly in over 80% of the trials. However, when one eye was covered and the annulus was presented on the blind spot of the uncovered eye, performance deteriorated significantly. To confirm that these results reflected filling-in, one monkey was trained to maintain fixation when two identical homogeneous disks appeared in opposite visual fields. When only one eye was uncovered, and the annulus was presented on the blind spot of the uncovered eye, the monkey maintained fixation in most of the trials. These results show that monkeys were unable to distinguish an annulus from a homogeneous disk when the annulus was presented on the blind spot. This indicates that color filling-in occurs at the blind spot in monkeys and opens possibility to physiological experiments to study the neural mechanisms of filling-in.

Type
Research Articles
Copyright
Copyright © Cambridge University Press 1994

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

Crane, H.D. & Piantanida, T.P. (1983). On seeing reddish green and yellowish blue. Science 221, 10781080.Google Scholar
Fiorani, M., Rosa, M.G.P., Gattas, 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, 85478551.Google Scholar
Gerrits, H.J.M. & Timmerman, G.J.M.E.N. (1969). The filling-in process in patients with retinal scotoma. Vision Research 9, 439442.CrossRefGoogle Scholar
Gerrits, H.J.M. & Vendrik, A.J.H. (1970). Simultaneous contrast, filling-in process and information processing in man's visual system. Experimental Brain Research 11, 411430.Google Scholar
Judge, S.J., Richmond, B.J. & Chu, F.C. (1980). Implantation of magnetic search coils for measurement of eye position: An improved method. Vision Research 20, 535538.CrossRefGoogle ScholarPubMed
Kawabata, N. (1982). Visual information processing at the blind spot. Perceptual and Motor Skills 55, 95104.CrossRefGoogle ScholarPubMed
Komatsu, H. & Yamane, S. (1992 a). Behavioral evidence of the filling-in at the blind spot of the monkey. Society for Neuroscience Abstract 18, 1398.Google Scholar
Komatsu, H. & Yamane, S. (1992 b). Color filling-in at the blind spot of the monkey: behavioral evidence. Neuroscience Research (Suppl.) 17, s242.Google Scholar
Krauskopf, J. (1963). Effect of retinal image stabilization on the appearance of heterochromatic targets. Journal of the Optical Society of America 53, 741744.CrossRefGoogle ScholarPubMed
Malpeli, J.G. & Baker, F.H. (1975). The representation of the visual Field in the lateral geniculate nucleus of Macaco mulatto. Journal of Comparative Neurology 161, 569594.Google Scholar
Nerger, J.L., Piantanida, T.P. & Larimer, J. (1993). Color appearance of filled-in backgrounds affects hue cancellation, but not detection thresholds. Vision Research 33, 165172.CrossRefGoogle Scholar
Paradiso, M.A. & Nakayama, K. (1991). Brightness perception and filling-in. Vision Research 31, 12211236.Google Scholar
Ramachandran, V.S. & Gregory, R.L. (1991). Perceptual filling in of artificially induced scotomas in human vision. Nature 350, 699702.CrossRefGoogle ScholarPubMed
Robinson, D.A. (1963). A method of measuring eye movement using a scleral search coil in a magnetic field. IEEE Transactions on Biomedical Electronics 10, 137145.Google ScholarPubMed
Walls, G.L. (1954). The filling-in process. American Journal of Optometry and Archives of American Academy of Optometry 31, 329341.Google Scholar
Yarbus, A.L. (1967). Eye Movements and Vision. New York: Plenum Press.CrossRefGoogle Scholar