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Billy Wooten Lab

Billy R. Wooten


Office: Hunter Lab room 302
Phone: (401) 863-3973
Related Links: Directory of Researchers at Brown 		wooten picture

Color Vision

Besides wavelength, many factors determine a stimulus' color. We have explored how color appearance is affected by luminance level, chromatic adaptation, spatial contrast, and temporal factors. We have also conducted experiments in the areas of color blindness, peripheral vision, and the relation between language and hue.

Achromatic Perception

The lightness, or gray tone of an achromatic stimulus, is influenced by many factors in addition to simple reflectance. My research group has studied a number of factors in order to assess how they affect lightness: illumination level, adaptation state, retinal disparity, and contour complexity.

wooten research figure

Percentage of blackness as a function of disparity. Two regression lines intersect the data points of each contrast condition, one for positive disparities and the other for negative disparities. All functions approximate zero slope. The date are averages for all subjects. This figure shows that lightness is independent of stereoscopic depth. From Dalby, T.A., Saillant, M.L., and Wooten, B.R. (1995)

Physiological Optics

The retinal image is determined not only by the physical stimulus, but also by the properties of the eye. Research in my laboratory, using psychophysical techniques, has examined such optical properties of the eye as intra-ocular scatter, lens absorption, and macular pigmentation.

The lab has developed an instrument to measure the density and distribution of the macular pigment in the human eye.We have provided an mp4 version and a wmv version of the of the procedure.
Note: right-clicking on either of these links will give you an option to Save As for later viewing . . .

Selected Publications

  • Hammond, B.R.and Wooten, B.R. (2004). Validity issues with the in vivo measurement of skin carotenoids using Raman spectroscopy. Investigative Dermatology, 122, 544-546.
  • Hammond, B.R.,and Wooten, B.R. (2003). Noninvasive assessment of the macular carotenoids. In Ciulla, T.A., Regillo, C.D. and Harris A. (Eds.). Retina and Optic Nerve Imaging. Lippincott, Williams & Wilkins, Delaware, 231-43.
  • Wooten, B.R.and Hammond, B.R. (2002). Macular Pigment: Influences on visual acuity and visibility. Progress in Retinal and Eye Research, 21, 225-240.
  • Hammond, B.R., Wooten, B.R.and Curran-Celentano. (2001). Carotenoids in the retina and lens: Possible acute and chronic effects on human visual performance. Archives of Biochemistry and Biophysics, 385, 41-46.
  • Wooten,B.R., Hammond, B.R., Land, R.L.,and Snodderly, D.M. (1999). A Practical Method for Measuring Macular Pigment Optical Density. Invest. Ophthalmol. Vis. Sci., 40, 2481-2489.
  • Hammond, B.R., Wooten, B.R. and Snodderly, D.M. (1998). Preservation of visual sensitivity of older subjects: association with macular pigment density Invest. Ophthalmol. Vis. Sci., 39, 397-406.
  • Hammond, B.R., Wooten, B.R.and Snodderly, D.M. (1997). Density of the human crystalline lens is related to the macular pigment carotenoids, lutein and zeaxanthin. Optometry and Vision Science, 74(7), 1-6.
  • Hammond, B.R., Wooten, B.R.and Snodderly, D.M. (1997). Individual variations in the spatial profile of human macular pigment. Journal of the Optical Society of America, 14(6), 1187-1196.
  • Hammond, B.R., Curran-Celentano, J., Judd, S., Fuld, K., Krinsky, N.I., Wooten, B.R. and Snodderly, D.M. (1996). Sex differences in macular pigment optical density: relation to plasma carotenoid concentrations and dietary patterns. Vision Research, 36(13), 2001-2012.
  • Dalby, T.A., Saillant, M.L.,and Wooten, B.R. (1995). The relation of lightness and stereoscopic depth in a simple viewing situation. Perception and Psychophysics, 57, 318-332.