Abstract
A shape can be more difficult to identify when other shapes are near it. For example, when several grating patches are viewed parafoveally, observers are unable to report the orientation of the central patch. This phenomenon, known as 'crowding,' has historically been confused with lateral masking, in which one stimulus attenuates signals generated by another stimulus. Here we show that despite their inability to report the orientation of an individual patch, observers can reliably estimate the average orientation, demonstrating that the local orientation signals are combined rather than lost. Our results imply that crowding is distinct from ordinary masking, and is perhaps related to texture perception. Under crowded conditions, the orientation signals in primary visual cortex are pooled before they reach consciousness.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
$209.00 per year
only $17.42 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Bennett, A. & Rabbetts, R. Clinical Vision Optics (Butterworths, Frome, Somerset, UK, 1989).
Bouma, H. Interaction effects in parafoveal letter recognition. Nature 226, 177–178 (1970).
Westheimer, G. & Hauske, G. Temporal and spatial interference with vernier acuity. Vision Res. 15, 1137–1141 (1975).
Levi, D., Klein, S. & Aitsabaomo, A. P. Vernier acuity, crowding and cortical magnification factor. Vision Res. 25, 963–967 (1985).
Westheimer, G., Shimamura, K. & McKee, S. P. Interference with line-orientation sensitivity. J. Opt. Soc. Am. 66, 332–338 (1976).
Andriessen, J. J. & Bouma, H. Eccentric vision: adverse interactions between line segments. Vision Res. 16, 71–78 (1976).
Dakin, S. C. & Watt, R. J. The computation of orientation statistics from visual texture. Vision Res. 37, 3181–3192 (1997).
Green, D. M. & Swets, J. A. Signal Detection Theory and Psychophysics (Wiley, New York, 1966).
Palmer, J., Verghese, P. & Pavel, M. The psychophysics of visual search. Vision Res. 40, 1227–1268 (2000).
Morgan, M., Castet, E. & Ward, R. Visual search for a tilted target: tests of the spatial uncertainty model. Q. J. Exp. Psychol. A 51, 347–370 (1998).
Baldassi, S. & Burr, D. C. Feature-based integration of orientation signals in visual search. Vision Res. 40, 1293–1300 (2000).
Hubel, D. H. & Wiesel, T. N. Receptive fields of single neurons in the cat's striate cortex. J. Physiol. (Lond.) 148, 574–591 (1959).
Heeley, D. W. & Buchanan-Smith, H. M. Mechanisms specialized for the perception of image geometry. Vision Res. 36, 3607–3627 (1996).
Morgan, M. J., Hole, G. J. & Ward, R. M. Evidence for positional coding in hyperacuity. J. Opt. Soc. Am. A 7, 297–304 (1990).
He, S., Cavanagh, P. & Intriligator, J. Attentional resolution and the locus of visual awareness. Nature 383, 334–337 (1996).
Wilkinson, F., Wilson, H. R. & Ellemberg, D. Lateral interactions in peripherally viewed texture arrays. J. Opt. Soc. Am. A 14, 2057–2068 (1997).
Levi, D. M. & Klein, S. A. Hyperacuity and amblyopia. Nature 298, 268–270 (1982).
Polat, U. & Sagi, D. The architecture of perceptual spatial interactions. Vision Res. 34, 73–78 (1994).
Usher, M., Bonneh, Y., Sagi, D. & Herrmann, M. Mechanisms for spatial integration in visual detection: a model based on lateral interactions. Spat. Vis. 12, 187–209 (1999).
Morgan, M. J. & Hotopf, N. Perceived diagonals in grids and lattices. Vision Res. 29, 1005–1015 (1989).
Malik, J. & Perona, P. Preattentive texture discrimination with early visual mechanisms. J. Opt. Soc. Am. A 7, 923–932 (1990).
Lin, L.-M. & Wilson, H. R. Fourier and non-Fourier pattern discrimination compared. Vision Res. 36, 1907–1918 (1996).
Dakin, S. C. Orientation variance as a quantifier of structure in texture. Spat. Vis. 12, 1–30 (1999).
Morgan, M. & Baldassi, S. How the human visual system encodes the orientation of a texture and why it makes mistakes. Curr. Biol. 7, 999–1002 (1997).
Solomon, J. A., Watson, A. B. & Morgan, M. J. Transducer model produces facilitation from opposite-sign flanks. Vision Res. 39, 987–992 (1999).
Solomon, J. A. & Morgan, M. J. Facilitation by collinear flanks is abolished by non-collinear flanks. Vision Res. 40, 279–286 (2000).
Sagi, D. & Julesz, B. “Where” and “what” in vision. Science 228, 1217–1219 (1985).
Solomon, J.A. & Morgan, M.J. Odd-men-out are poorly localised in brief exposures. J. Vision, http://journalofvision.org, 1, 9–17 (2001).
Kolb, F. C. & Braun, J. Blindsight in normal observers. Nature 377, 336–338 (1995).
Morgan, M. J., Mason, A. J. S. & Solomon, J. A. “Blindsight” in normal observers. Nature 385, 401–402 (1997).
Crick, F. C. & Koch, C. Nature 375, 121–123 (1995).
Efron, B. Bootstrap methods: another look at the jackknife. Ann. Statistics 7, 1–26 (1979).
Pelli, D. G. & Zhang, L. Accurate control of contrast on microcomputer displays. Vision Res. 31, 1337–1350 (1991).
Watson, A. B. & Solomon, J. A. Psychophysica: mathematica notebooks for psychophysical experiments (cinematica—psychometrica—quest). Spat. Vis. 10, 447–466 (1997).
Acknowledgements
This work was supported by a grant from the Engineering and Physical Sciences Research Council (EPSRC) of Great Britain. The experiments were carried out at the Institute of Cognitive Neuroscience, University College London.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Parkes, L., Lund, J., Angelucci, A. et al. Compulsory averaging of crowded orientation signals in human vision. Nat Neurosci 4, 739–744 (2001). https://doi.org/10.1038/89532
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/89532
This article is cited by
-
People perception and stereotype-based responding: task context matters
Psychological Research (2023)
-
Electrophysiological signatures of temporal context in the bisection task
Experimental Brain Research (2023)
-
Crowding results from optimal integration of visual targets with contextual information
Nature Communications (2022)
-
Mixture-modeling approach reveals global and local processes in visual crowding
Scientific Reports (2022)
-
Ensemble perception without phenomenal awareness of elements
Scientific Reports (2022)