Abstract
The visual system of primates has two anatomical pathways: magno (M) and parvo (P). Here we report a novel technique for selectively stimulating the magnocellular pathway in man. The stimulus was a texture border between black spots and white spots displayed on a uniform gray field. This stimulus (Frame 1) was followed by Frame 2, in which all the black spots were replaced with white spots and all the white spots with black. The procedure was repeated in a continuous cycle; that is, spots reversed polarity without changing positions. At high temporal frequencies (20 Hz), subjects could not see the difference between the flickering spots, but could see a phantom contour separating the two indiscriminable regions. The difference between the spots themselves could be discriminated only at about 17 Hz. Since the M pathway can follow high flicker rates but is insensitive to the sign of the border, we suggest that the phantom border is seen exclusively by the M system. The P system, on the other hand, can report the sign of the border, but only at low flicker rates. Phantom contours provide a psychophysical scalpel for producing a temporary “lesion” in the par-vocellular pathway of intact human subjects. One could therefore repeat all of classical psychophysics and physiology using phantom contours to determine whether or not a given visual process receives an M input. Also, these stimuli might provide a simple diagnostic test for revealing the loss of M-cell function that occurs in early glaucoma.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Allman, J., Miezin, F., & McGuinness, E. L. (1985). Direction and velocity specific responses beyond the classical receptive field in the middle temporal area (MT). Perception, 14, 105–126.
Blakemore, C., Carpenter, R. H. S., & Georgeson, M. A. (1970). Lateral inhibition between orientation detectors in the human visual system. Nature, 228, 37–39.
Boynton, R. M. (1979). Human color vision. New York: Holt, Rhine-hart & Winston.
Braddick, O. J.. (1974). A short range process in apparent motion. Vision Research, 26, 1751–1761.
Cavanagh, P., Boeglin, J., & Favreau, O. E. (1985). Perception of motion in equiluminous kinematograms. Perception, 14, 151–162.
De Monasterio, F. M., Gouras, P., & Tolhurst, D. J. (1976). Spatial summation, response pattern and conduction velocity of ganglion cells of the rhesus monkey retina. Vision Research, 16, 674–678.
Derrington, A. M., & Lennie, P. (1984). Spatial and temporal contrast sensitivities of neurons in the lateral geniculate nucleus of macaque. Journal of Physiology (London), 357, 219–240.
Dreher, B., Fukada, Y., & Rodeick, W. (1976). Identification classification and anatomical segregation of cells with x-like and y-like properties in the LGN of old-world primates. Journal of Physiology, 258, 433–452.
Gouras, P. L. (1968). Identification of cone mechanism in monkey ganglion cells. Journal of Physioloogy, London, 199, 533–547.
Livingstone, M., & Hubel, D. H. (1987). Psychophysical evidence for separate channels for the perception of form, color, movement and depth. Journal of Neuroscience, 7, 3416–3468.
Merigan, W. H., & Eskin, T. A. (1986). Spatiotemporal vision of macaques with severe loss of P retinal ganglion cells. Vision Research, 26, 1751–1761.
Quigley, H. A., Addicks, E. M., & Green, W. R. (1982). Optic nerve damage in human glaucoma. Archives of Ophthalmology, 100, 135–146.
Ramachandran, V. S. (1986). Visual perception: A biological theory. In S. Petry & G. Meyer (Eds.), Illusory contours. Berlin: Springer-Verlag.
Ramachandran, V. S. (1988). Perception of depth from shading. Scientific American, 269, 76–83.
Ramachandran, V. S. (1990). Visual perception in people and machines. In A. Blake & T. Troscianko (Eds.), AI and the eye. Briston: Wiley.
Ramachandran, V. S. (1991). 2-D or not 2-D—that is the question. In R. Gregory, J. Harris, & P. Heard (Eds.), The artful brain. Oxford: Oxford University Press.
Ramachandran, V. S., & Gregory, R. L. (1978). Does color provide an input to human motion perception. Nature, 275, 55–56.
Ramachandran, V. S., Rao, V. M., & Vidyasagar, T. R. (1973). Apparent motion with subjective contours. Vision Research, 13, 1399–1401.
Rogers-Ramachandran, D., & Ramachandran, V. S. (1991a). Phantom contours: A new class of stimuli that selectively activate the magnocellular pathway in man. Investigative Ophthalmology & Visual Science (Supplement) 32, 1034.
Rogers-Ramachandran, D., & Ramachandran, V. S. (1991b). Phantom contours: A new class of stimuli that selectively activate the magnocellular pathway in man. Society for Neurosciences Abstracts.
Schiller, P. H., & Logothetis, N. K. (1990). The color opponent and broad band channels in the primate visual system. TINS, 13, 392–398.
Van Essen, D. C. (1979). Visual cortial areas. In W. N. Cowan (Ed.), Annual Reviews of Neuroscience, 2, 227–263.
Wiesel, T. N., & Hubel, D. H. (1966). Spatial and chromatic interactions in the lateral geniculate body of the rhesus monkey. Journal of Neurophysiology. 29, 1115–1156.
Zeki, S. M. (1978). Functional specialization in the visual cortex of the rhesus monkey. Nature, 274, 423–428.
Author information
Authors and Affiliations
Additional information
V.S.R. was supported by grants from the Air Force Office of Scientific Research (No. 89-0414) and the academic senate of the University of California. We thank Jennifer Luckrits for assistance with these experiments and Chandramani Ramachandran, John Allman, Pamela Sample, and Robert Weinreb for stimulating discussions.
Rights and permissions
About this article
Cite this article
Ramachandran, V.S., Rogers-Ramachandran, D.C. Phantom contours: A new class of visual patterns that selectively activates the magnocellular pathway in man. Bull. Psychon. Soc. 29, 391–394 (1991). https://doi.org/10.3758/BF03333951
Received:
Published:
Issue Date:
DOI: https://doi.org/10.3758/BF03333951