Harvey Smallman, Ph.D. - Home Page

Contact Details

Dr. Harvey S. Smallman
Department of Psychology
University of California at San Diego
9500 Gilman Drive
La Jolla, CA 92093-0109
USA
+1-619-534-3924 +1-619-534-7190 e-mail me atSmallman@psy.ucsd.edu

Last updated27th Feb 1997

Current research interests and collaborators

I am interested in revealing the mechanisms of human vision using non-invasive psychophysical techniques. I am fascinated by how we can gain insight into the physiology of our own visual nervous systems through perceptual observations. In particular, I s tudy human binocular stereopsis (the reconstruction of relative visual depth from binocular disparities), and also the sequence of processing stages that underly spatial vision. Computational models of these processes are multiplying rapidly and I want to critically distinguish between them. Psychophysics is particularly powerful in that it is often the only way to test these models.

Recent work includes,

* Using laser interferometry to by-pass the eye's optics to demonstrate that there are adaptable neural mechanisms that detect extremely fine detail. There can be much less cortical neural spatial integration than was previously thought.

* Testing whether the neural code binocular disparity is like colour vision (three mechanisms broadly-tuned to walevlength) or audition (many mechanisms narrowly-tuned for frequency).

* Testing which matching constraints are actually employed by the human visual system to solve the correspondence problem (that's the problem of what in one eye matches what in the other eye).

I am currently working on dissecting the order of linear and non-linear stages of information processing in early vision. My work shows that an early retinal non-linearity may precede a bank of linear spatial filters (receptive fields). This is interesting because others are trying to overhaul notions of the linearity of disparity detectors (for instance) but they may be mistaking their late nonlinearity for this early one.

Collaborations are ongoing with workers at the Centre for Neuroscience at the University of Edinburgh , and the Smith-Kettlewell Eye Research Institute in San Francisco

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Research Publications

Popple,A.V., Smallman, H.S., & Findlay,J.M (1997) The area of spatial integration for initial horizontal disparity vergence. Vision Reseach (submitted).

Harris,J.M., McKee,S.P., and Smallman,H.S. (1997) Fine-scale processing of human binocular stereopsis. Journal of the Optical Society of America A, (submitted).

Smallman, H.S., & MacLeod, D.I.A. (1997) Spatial scale interactions in stereo sensitivity and the neural representation of binocular disparity. Perception,(in press).click for abstract

McKee,S.P., Watamaniuk,S.N.J., Harris,J.M., Smallman,H.S., and Taylor,D.G. (1997) Is stereopsis effective in breaking camouflage for moving targets? Vision Reseach , 37, 2047-2055..click for abstract

McKee, S.P. & Smallman, H.S. (1997) Size and Speed Constancy, in Perceptual Constancies: Why things look as they do. Walsh, V., & Kulikowski, J.J. (Eds.) Cambridge University Press: New York, (in press).click for abstract

Smallman,H.S., MacLeod, D.I.A., He,S., & Kentridge,R.K. (1996) Fine grain of the neural representation of human spatial vision. Journal of Neuroscience , 16, 1852-1859.click for abstract

Smallman,H.S., & McKee,S.P. (1995) A contrast ratio constraint on stereo matching. Proceedings of the Royal Society of London, Series B,260, 265-271.click for abstract

McKee,S.P., Bravo,M.J., Smallman,H.S., & Legge,G.E. (1995) The `uniqueness constraint' and binocular masking. Perception, 24, 49-65.click for abstract

Smallman, H.S. (1995) Fine-to-Coarse scale disambiguation in stereopsis.Vision Research, 35 (8), 1047-1060.click for abstract

Smallman, H.S., & MacLeod, D.I.A. (1994) Size-disparity correlation in stereopsis at contrast threshold. Journal of the Optical Society of America A,11 (8), 2169-2183. click for abstract

Smallman, H.S., & Boynton, R.M. (1993) On the usefulness of basic colour coding in an information display. Displays, 14 (3), 158-165.click for abstract

Smallman, H.S., & Boynton, R.M. (1990) Segregation of basic colors in an information display. Journal of the Optical Society of America A, 7,1985-1994.click for abstract

Boynton, R.M., Fargo, L., Olson, C.X., & Smallman, H.S. (1989) Category effects in color memory. Color Research and Application, 14,229-234.click for abstract

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Books reviews

Smallman,H.S. (1996) Review of Wandell's "Foundations of Vision". Perception, 25, 751-752.

Conference presentations and conference abstracts

Popple,A.V., Smallman, H.S., & Findlay,J.M. (1997) Spatial integration for initial horizontal disparity vergence Investigative Ophthalmology and Visual Science (Suppl.) 37/4, (accepted for presentation).

Smallman,H.S., MacLeod, D.I.A. (1996) Spatial scale interactions in stereo sensitivity. Paper presented at U. DurhamWorkshop on Spatial Scale interactions in Vision and Visual Perception, Durham, UK, 16-18th September, 1996.click for abstract

Harris,J.M., Smallman,H.S., & McKee,S.P. (1996) The finest spatial scale for human binocular stereopsis.Paper presented at U. DurhamWorkshop on Spatial Scale interactions in Vision and Visual Perception, Durham, UK, 16-18th September, 1996.click for abstract

Smallman,H.S., MacLeod, D.I.A., He,S., & Kentridge,R.K. (1996) Fine grain of the neural representation of human spatial vision. Brain Res. Assoc. Abstr., 13, p 59.

Harris,J.M., Smallman,H.S., & McKee,S.P. (1996) Fine-scale human disparity processing. Brain Res. Assoc. Abstr., 13, p 59.

Smallman, H.S., & Harris, J.M. (1996) Nonlinear visual distortion: an effective expansive nonlinearity from asymmetry in ON and OFF pathways. Investigative Ophthalmology and Visual Science (Suppl.) 37/4, S232.click for abstract

Smallman, H.S., & Harris, J.M. (1995) Spatial frequency-selectivity of contrast-modulated masking. Perception(Suppl.),, 24, 127.click for abstract

Harris, J.M., & Smallman, H.S. (1995) Distortion products from an expansive visual nonlinearity. Perception(Suppl.),, 24, 126.click for abstract

Smallman, H.S., & McKee, S.P. (1995) A contrast ratio constraint on stereo matching. Investigative Ophthalmology and Visual Science (Suppl.), 36/4, 230.click for abstract

He, S., Smallman, H.S., & MacLeod, D.I.A. (1995) Neural and cortical limits on visual resolution. Investigative Ophthalmology and Visual Science (Suppl.), 36/4, 438.click for abstract

McKee, S.P., Harris, J.M., & Smallman, H.S. (1995) Minimum size for human disparity correlation. Investigative Ophthalmology and Visual Science (Suppl.), 36/4, 365.click for abstract

Smallman, H.S., & MacLeod, D.I.A. (1994) Paradoxical effects of adapting to large disparities: Constraining population code models of disparity. Investigative Ophthalmology and Visual Science (Suppl.), 35/4, 1917.click for abstract

Smallman, H.S., & MacLeod, D.I.A. (1993) Interactions across spatial scales and the size-disparity correlation in stereopsis. In OSA Meeting Technical Digest, 1993. (Optical Society of America, Washington, D.C., 1993), Vol, 16, p. 186.click for abstract

Smallman, H.S., & MacLeod, D.I.A. (1993) A size-disparity correlation in stereopsis at contrast threshold. Poster presented at NATO Advanced Workshop on Binocular Stereopsis and Optic Flow, Toronto 22nd-26th June 1993.

Smallman, H.S. (1993) Disparity-selective effects in contrast detection of 2D noise patterns in high contrast surrounds. Investigative Ophthalmology and Visual Science (Suppl.), 34/4, 1187.click for abstract

McKee, S.P., Bravo, M.J., Smallman, H.S., and Legge, G.E. (1993) "Uniqueness" is not a constraint on human stereo matching. Investigative Ophthalmology and Visual Science (Suppl.), 34/4, 1437.click for abstr act

Welch, L., & Smallman, H.S. (1992) Is there motion mislocation in depth? Investigative Ophthalmology and Visual Science (Suppl.), 33, 1333.

Smallman, H.S., & MacLeod, D.I.A. (1992) Fine-to-coarse scale disambiguation in stereopsis. Investigative Ophthalmology and Visual Science (Suppl.), 33, 1369.click for abstract

Smallman, H.S., & MacLeod, D.I.A. (1991) Disparity averaging across spatial scales. In OSA Meeting Technical Digest, 1991. (Optical Society of America, Washington, D.C., 1991), Vol, 17, pp. 194-195.click fo r abstract

Boynton, R.M., & Smallman, H.S. (1990) Visual search for basic versus nonbasic chromatic targets. Proceedings of the SPIE Conference on Human Vision, Visual Processing and Digital Display, Brill, M.H. (Ed.), Proc. Soc. Photo-Opt. Instrum. Eng., 1250, 9-18.

Boynton, R.M., & Smallman, H.S. (1989) Segregation of basic colors in an information display. Topical Meeting on Applied Vision, OSA Technical Digest series, 16, 164-167.

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