Robert Shapley

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Robert Shapley is an American neurophysiologist,the Natalie Clews Spencer Professor of the Sciences at New York University, a professor in the Center for Neural Science and an associate member of the Courant Institute of Mathematical Sciences. [1]

Shapley received an A.B. Degree from Harvard College (1965) and a Ph.D. from Rockefeller University (1970). With a Helen Hay Whitney Postdoctoral Fellowship, he went to Northwestern University and the University of Cambridge. He served on the US National Research Council’s Committee on Vision.He graduated from Harvard University, and from Rockefeller University with a PhD in neurophysiology and biophysics. In 1986 he received a MacArthur Foundation Prize Fellowship [2] from the MacArthur Fellows Program

Academic Work[edit]

Among Shapley’s findings were his discoveries about the X and Y retinal ganglion cells in the cat retina. He discovered that the Y cell collected excitatory signals from many small spatial mechanisms called “nonlinear subunits”[3] and that there was a contrast gain control, a nonlinear feedback within the retina that adjusted the signal-transfer properties of the retina contingent on the space-averaged stimulus contrast.[4]

He also worked with the visual system of macaque monkeys, and found: its parallel processing of visual signals[5]; the nature of retinal computation of color[6][7]; and that the orientation-selectivity of neurons in the primary visual cortex, or V1, of evolves with time.[8] Other findings that have elucidated the workings of V1 include the following: V1 cells are tuned for color and for spatial pattern[9][10][11]; fluctuations in the local field potential in V1 appear to be caused by noise and have no autocoherence or phase-memory over time[12][13]; and there is not a single fixed cortical receptive field for each neuron.[14]

More recently, he has been studying how color is represented in the visual cortex, as a follow-up to his earlier work on parallel pathways for color and brightness contrast in the retina. He has been examining visual perception and the art of painting--he wrote an editorial in the journal Perception about the work of the American artist Ellsworth Kelly.[15]

Works[edit]

References[edit]

  1. ^ http://www.cns.nyu.edu/corefaculty/Shapley.php
  2. ^ http://www.macfound.org/fellows/class/august-1986/
  3. ^ Hochstein, S. and Shapley, R. (1976) Linear and nonlinear spatial subunits in Y cat retinal ganglion cells. J.Physiol., 262, 265-284.
  4. ^ Shapley, R. and Victor, J.D. (1978) The effect of contrast on the transfer properties of cat retinal ganglion cells, J.Physiol., 285, 275-298.
  5. ^ Shapley R Kaplan E Soodak R. (1981) Spatial summation and contrast sensitivity of X and Y cells in the lateral geniculate nucleus of the macaque Nature 292, 543-545.
  6. ^ Reid, R.C. and Shapley, R. (1992) Spatial structure of cone inputs to receptive fields in primate lateral geniculate nucleus, Nature, 356, 716-718.
  7. ^ Reid RC and Shapley RM (2002) Space and time maps of cone photoreceptor signals in macaque lateral geniculate nucleus. J. Neurosci. 22:6158-6175.
  8. ^ Ringach, D., Hawken, M. and Shapley, R. (1997) The dynamics of orientation tuning in the macaque monkey striate cortex, Nature, 387, 281-284.
  9. ^ Johnson EA Hawken MJ and Shapley RM (2001) The Spatial Transformation of Color in the Primary Visual Cortex of the Macaque Monkey, Nature Neuroscience 4: 409-16.
  10. ^ Johnson EN, Hawken MJ, Shapley R. (2004) Cone Inputs in Macaque Primary Visual Cortex. J Neurophysiol. 91:2501-14.
  11. ^ Johnson EN, Hawken MJ, Shapley R. (2008) The orientation selectivity of color-responsive neurons in macaque V1. J Neurosci. 28:8096-8106.
  12. ^ Burns SP, Xing D, Shelley MJ, Shapley RM (2010) Searching for autocoherence in the cortical network with a time-frequency analysis of the local field potential. J Neurosci. 30:4033-47.
  13. ^ Burns SP, Xing D, Shapley RM. (2011) Is gamma-band activity in the local field potential of V1 cortex a "clock" or filtered noise? J Neurosci. 31:9658-64.
  14. ^ Yeh CI, Xing D, Williams PE, Shapley RM. (2009) Stimulus ensemble and cortical layer determine V1 spatial receptive fields. Proc Natl Acad Sci U S A. 106:14652-7.
  15. ^ Shapley, R. (1996) Guest editorial: Art and the perception of nature: Illusory contours in the paintings of Ellsworth Kelly, Perception, 25, 1259-1261.

External links[edit]