Abstract
When a stimulus oscillates in both colour and direction of motion, changes in colour must lag behind those in direction if they are to be seen as concurrent. It has been argued that this lag is the consequence of asynchronous visual processing, with colour being processed more rapidly than motion. This proposal is contentious: it has been criticized on the basis that the time-course of cortical activity may not correlate directly with that of perceptual experience. Here, we demonstrate that the extent of the apparent asynchrony can vary according to the prevailing stimulus conditions. The apparent asynchrony is greatest if the stimulus is composed of opponent directions of motion and is reduced if the angular difference between the directions is reduced. This pattern of results suggests that asynchronous neural activity arises, in part, as a consequence of differential levels of inhibition within relatively independent cortical structures.
Full Text
The Full Text of this article is available as a PDF (194.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- 21st European Conference on Visual Perception. Oxford, England, 24-28 August 1998. Abstracts. Perception. 1998;27 (Suppl):1–212. [PubMed] [Google Scholar]
- Arnold D. H., Clifford C. W., Wenderoth P. Asynchronous processing in vision: color leads motion. Curr Biol. 2001 Apr 17;11(8):596–600. doi: 10.1016/s0960-9822(01)00156-7. [DOI] [PubMed] [Google Scholar]
- Barlow H. B., Levick W. R. The mechanism of directionally selective units in rabbit's retina. J Physiol. 1965 Jun;178(3):477–504. doi: 10.1113/jphysiol.1965.sp007638. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bartels A., Zeki S. The theory of multistage integration in the visual brain. Proc Biol Sci. 1998 Dec 7;265(1412):2327–2332. doi: 10.1098/rspb.1998.0579. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bolz J., Rosner G., Wässle H. Response latency of brisk-sustained (X) and brisk-transient (Y) cells in the cat retina. J Physiol. 1982 Jul;328:171–190. doi: 10.1113/jphysiol.1982.sp014258. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carandini M., Heeger D. J., Movshon J. A. Linearity and normalization in simple cells of the macaque primary visual cortex. J Neurosci. 1997 Nov 1;17(21):8621–8644. doi: 10.1523/JNEUROSCI.17-21-08621.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Daw N. W. Colour-coded ganglion cells in the goldfish retina: extension of their receptive fields by means of new stimuli. J Physiol. 1968 Aug;197(3):567–592. doi: 10.1113/jphysiol.1968.sp008575. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eagleman D. M., Sejnowski T. J. Motion integration and postdiction in visual awareness. Science. 2000 Mar 17;287(5460):2036–2038. doi: 10.1126/science.287.5460.2036. [DOI] [PubMed] [Google Scholar]
- Favreau O. E., Emerson V. F., Corballis M. C. Motion perception: a color-contingent aftereffect. Science. 1972 Apr 7;176(4030):78–79. doi: 10.1126/science.176.4030.78. [DOI] [PubMed] [Google Scholar]
- Felleman D. J., Van Essen D. C. Distributed hierarchical processing in the primate cerebral cortex. Cereb Cortex. 1991 Jan-Feb;1(1):1–47. doi: 10.1093/cercor/1.1.1-a. [DOI] [PubMed] [Google Scholar]
- Gawne T. J., Kjaer T. W., Richmond B. J. Latency: another potential code for feature binding in striate cortex. J Neurophysiol. 1996 Aug;76(2):1356–1360. doi: 10.1152/jn.1996.76.2.1356. [DOI] [PubMed] [Google Scholar]
- Johnston A., Nishida S. Time perception: brain time or event time? Curr Biol. 2001 Jun 5;11(11):R427–R430. doi: 10.1016/s0960-9822(01)00252-4. [DOI] [PubMed] [Google Scholar]
- Livingstone M., Hubel D. Segregation of form, color, movement, and depth: anatomy, physiology, and perception. Science. 1988 May 6;240(4853):740–749. doi: 10.1126/science.3283936. [DOI] [PubMed] [Google Scholar]
- Maffei L., Fiorentini A., Bisti S. Neural correlate of perceptual adaptation to gratings. Science. 1973 Dec 7;182(4116):1036–1038. doi: 10.1126/science.182.4116.1036. [DOI] [PubMed] [Google Scholar]
- Maunsell J. H., Ghose G. M., Assad J. A., McAdams C. J., Boudreau C. E., Noerager B. D. Visual response latencies of magnocellular and parvocellular LGN neurons in macaque monkeys. Vis Neurosci. 1999 Jan-Feb;16(1):1–14. doi: 10.1017/s0952523899156177. [DOI] [PubMed] [Google Scholar]
- Moutoussis K., Zeki S. A direct demonstration of perceptual asynchrony in vision. Proc Biol Sci. 1997 Mar 22;264(1380):393–399. doi: 10.1098/rspb.1997.0056. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moutoussis K., Zeki S. Functional segregation and temporal hierarchy of the visual perceptive systems. Proc Biol Sci. 1997 Oct 22;264(1387):1407–1414. doi: 10.1098/rspb.1997.0196. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Munk M. H., Nowak L. G., Girard P., Chounlamountri N., Bullier J. Visual latencies in cytochrome oxidase bands of macaque area V2. Proc Natl Acad Sci U S A. 1995 Feb 14;92(4):988–992. doi: 10.1073/pnas.92.4.988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nijhawan R. Motion extrapolation in catching. Nature. 1994 Jul 28;370(6487):256–257. doi: 10.1038/370256b0. [DOI] [PubMed] [Google Scholar]
- Schiller P. H., Malpeli J. G. Functional specificity of lateral geniculate nucleus laminae of the rhesus monkey. J Neurophysiol. 1978 May;41(3):788–797. doi: 10.1152/jn.1978.41.3.788. [DOI] [PubMed] [Google Scholar]
- Snowden R. J., Treue S., Erickson R. G., Andersen R. A. The response of area MT and V1 neurons to transparent motion. J Neurosci. 1991 Sep;11(9):2768–2785. doi: 10.1523/JNEUROSCI.11-09-02768.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Whitney D., Murakami I. Latency difference, not spatial extrapolation. Nat Neurosci. 1998 Dec;1(8):656–657. doi: 10.1038/3659. [DOI] [PubMed] [Google Scholar]
- Zeki S. M. Functional specialisation in the visual cortex of the rhesus monkey. Nature. 1978 Aug 3;274(5670):423–428. doi: 10.1038/274423a0. [DOI] [PubMed] [Google Scholar]
- Zeki S., Bartels A. The asynchrony of consciousness. Proc Biol Sci. 1998 Aug 22;265(1405):1583–1585. doi: 10.1098/rspb.1998.0475. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zeki S., Bartels A. Toward a theory of visual consciousness. Conscious Cogn. 1999 Jun;8(2):225–259. doi: 10.1006/ccog.1999.0390. [DOI] [PubMed] [Google Scholar]
- Zihl J., von Cramon D., Mai N. Selective disturbance of movement vision after bilateral brain damage. Brain. 1983 Jun;106(Pt 2):313–340. doi: 10.1093/brain/106.2.313. [DOI] [PubMed] [Google Scholar]
- ffytche D. H., Guy C. N., Zeki S. The parallel visual motion inputs into areas V1 and V5 of human cerebral cortex. Brain. 1995 Dec;118(Pt 6):1375–1394. doi: 10.1093/brain/118.6.1375. [DOI] [PubMed] [Google Scholar]