Papers on pre-attentive vision or visual segmentation.

Note: Publications before late 2002 were published under name "Zhaoping Li (i.e., Li Z.)", and those after were published under name "Li Zhaoping (i.e., Zhaoping L.)". In order to avoid database errors and confusions, please cite each paper with its published author name.

May K. A. & Zhaoping L. A (2009) Effects of surrounding frame on visual search for vertical or tilted bars Journal of Vision, 9(13):20, 1-19,, doi:10.1167/9.13.20.

Zhaoping L., Guyader N., and Lewis A (2009) Relative contributions of 2D and 3D cues in a texture segmentation task, implications for the roles of striate and extrastriate cortex in attentional selection Journal of Vision, 9(11):20, 1-22,, doi:10.1167/9.11.20

Zhaoping L. (2009) Perceptual learning of Pop-out and the primary visual cortex Learning & Perception 1:135-146.

Zhaoping L. (2008) Attention capture by eye of origin singletons even without awareness --- a hallmark of a bottom-up saliency map in the primary visual cortex. Journal of Vision, 8(5):1, 1-18,, doi:10.1167/8.5.1

Jingling L. & Zhaoping L. (2008) Change detection is easier at texture border bars when they are parallel to the border: Evidence for V1 mechanisms of bottom-up salience , Perception 37(2): 197-206

Koene AR and Zhaoping L. Salience from combined feature contrasts, evidence for feature specific salience interaction , in press for Journal of Vision (2007).

Zhaoping L. and May K.A. (2007) Psychophysical tests of the hypothesis of a bottom-up saliency map in primary visual cortex , Public Library of Science, Computational Biology 3(4):e62. doi:10.1371/journal.pcbi.0030062.

Zhaoping L. and Dayan P. (2006) Pre-attentive visual selection Published in Neural Networks 19(9):1437-1439.

Zhaoping L. Theoretical Understanding of the early visual processes by data compression and data selection in Network: Computation in neural systems 17(4):301-334 (2006).

Zhaoping L. and Snowden RJ (2006) A theory of a saliency map in primary visual cortex (V1) tested by psychophysics of color-orientation interference in texture segmentation. , Visual Cognition 14(4/5/6/7/8):911-933

Zhaoping L. (2005) Border Ownership from Intracortical Interactions in Visual Area V2 , in NEURON, Vol. 47, 143-153 (Note that the version downloaded here has better fonts, and fewer typo errors, in math expressions for those interested in technical details. [ The version in Journal is here ] ) [ A Preview on this article by K. Nakayama]

Zhaoping L. The primary visual cortex creates a bottom-up saliency map. In ``Neurobiology of Attention" Eds L. Itti, G. Rees and J.K. Tsotsos, Elsevier, 2005, Chapter 93, page 570-575

Zhaoping L. and May K. IRRELEVANCE OF FEATURE MAPS FOR BOTTOM UP VISUAL SALIENCY IN SEGMENTATION AND SEARCH TASKS (click here for the word file containing stimulus patterns) Presented at Annual Meeting of Society for Neuroscience, Oct. 2004, San Diego, USA.

Zhaoping L. V1 mechanisms and some figure-ground and border effects. In Journal of Physiology, Paris 97 (4-6) 503-515 (2003) Abstract

Freeman E., Driver J., Sagi D, and Zhaoping L. Top-Down Modulation of Lateral Interactions in Early Vision: Does Attention Affect Integration of the Whole or Just Perception of the Parts? , Current Biology Volume 13, Issue 11 , 27 May 2003, Pages 985-989 [abstract]

Zhaoping L. (2002) Pre-attentive segmentation and correspondence in stereo, published at Philosophical Transactions of The Royal Society, Biological Sciences, Vol. 357, Number 1428, page 1877-1883 [abstract]

Li Z. (2002) Understand conjuction and double feature searches by a saliency map in primary visual cortex
Presentation at Second annual meeting of Vision Science Society, May 10-15th, 2002, Sarasota, Florida, USA.

Li Z. (2002) A saliency map in primary visual cortex
Published in Trends in Cognitive Sciences Vol 6. No.1. Jan. 2002, page 9-16 [abstract]

Li Z. (2001)
Modeling pre-attentive stereo grouping by intracortical interactions in early visual cortex (postscript) or PDF version
Presented at 1st Annual Meeting of Vision Sciences Society, Sarasota, Florida, May 4-8th, 2001.
Published in Journal of Vision, 1(3), Abstract 168. [abstract]

Li Z. and Hertz J. (2000)
Multiple zones of contextual surround for V1 receptive fields (postscript) Or PDF version
Presented at Annual Meetings of Society for Neuroscience, 2000. Abstract # 211.10 [abstract]

Li Z. (2001)
Computational design and nonlinear dynamics of a recurrent network model of the primary visual cortex or PDF version
Neural Computation 13/8, p.1749-1780, 2001 [abstract]
(Please note that before Nov. 1st 2000, a wrong version of the manuscript was mistakenly posted. The current version is the correct one.)

Li Z. (1999)
Can V1 mechanisms account for figure-ground and medial axis effects? or PDF version
In Advances in Neural Information Processing Systems 12. MIT Press, Cambridge, MA, Editors: SA Solla, TK Leen \& K-R Muller P. 136-142. [abstract]

Li Z. (1999)
Contextual influences in V1 as a basis for pop out and asymmetry in visual search
In Proceedings of National Academy of Science, USA Volume 96, 1999. Page 10530-10535 [abstract]

Li Z. (1999)
Visual segmentation by contextual influences via intracortical interactions in primary visual cortex (Postscript) Or PDF version
In Network: Computation in Neural Systems Volume 10, Number 2, May 1999. Page 187-212 [abstract]
For readers more interested in relations of this work with physiological/psychophysical data and experiments, (and less mathematical analysis), see the article below.
Correction: In Oct. 2000, a typo was discovered on page 209 (page 23 of the manuscript), 9th line from the bottom of the page. "d >= 10" printed in the published version should be "d/cos( beta/4) >= 10" instead. This is an error in a model parameter, and this error should lead to quantitative (but not much qualitative) changes in model performance compared to those presented in this paper. Also, Delta (theta) in the expression for W means |Delta (theta)|. The same typo was also in the published version of Li Z. 1998 Neural Computation, but is corrected in the version below posted on this webpage (below). Hence, for all correct parameters of the model, download this paper.


Li Z. (2000)
Pre-attentive segmentation in the primary visual cortex (postscript) Or PDF version
Published in Spatial Vision , Volume 13, Number 1, p. 25-50, (2000). [abstract]
For readers more interested in analytical and mathematical details, and the relations of this work with other modeling and computer vision literature, see the article above.

Li Z. (1998) Visual segmentation without classification: A proposed function for primary visual cortex
in Perception Vol. 27, supplement, p 45. (ECVP, 1998, Oxford, England).

Li Z. (1998)
A neural model of contour integration in the primary visual cortex (postscript) Or PDF version
In Neural Computation. 10. 903-940, 1998 [abstract]


The following are the earlier publications, or, the pre-print/technical report/shorter versions, of this line of work.

Li Z. (1999)
Primary visual cortex as a saliency network for pre-attentive segmentation
Presented as Poster number 10 (page 104 in the abstract book) at 3rd Annual Vision Research Conference -- ``Pre-attentive and Attentive Mechanisms in Vision", May 7-8, 1999, a two day satellite symposium prior to the 1999 meeting of ARVO. Fort Lauderdale, Florida, USA.
  • Li Z. (1999)
    A V1 model of pop out and asymmetry in visual search
    In Advances in Neural Information Processing Systems 11 M. S. Kearns, S. A. Solla, and D. A. Cohn, editors, page, 796-802, MIT Press, Cambridge, MA, June 1999. [abstract]
  • Li Z. (1998)

  • Visual segmentation without classification in a model of the primary visual cortex.
    MIT, AI Memo #1613, 1997 [abstract]
  • Li Z. (1998)

  • Pre-attentive segmentation in the primary visual cortex.
    MIT, AI Memo #1640, 1998 [abstract]
  • Li Z. (1997)

  • Primary cortical dynamics for visual grouping
    Published in Theoretical aspects of neural computation K.M. Wong, I. King, and D.Y. Yeung (eds) page 155-164. Springer-verlag January 1998 [abstract]