English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Spatial distributions of cone inputs to cells of the parvocellular pathway investigated with cone-isolating gratings.

MPS-Authors
/persons/resource/persons36469

Lee,  B. B.
Emeritus Group of Membrane Biophysics, MPI for Biophysical Chemistry, Max Planck Society;

Fulltext (public)

1406656.pdf
(Publisher version), 2MB

Supplementary Material (public)
There is no public supplementary material available
Citation

Lee, B. B., Shapley, R. M., Hawken, M. J., & Sun, H. (2012). Spatial distributions of cone inputs to cells of the parvocellular pathway investigated with cone-isolating gratings. Journal of the Optical Society of America A-Optics Image Science and Vision, 29(2), A223-A232. doi:10.1364/JOSAA.29.00A223.


Cite as: http://hdl.handle.net/11858/00-001M-0000-000F-4FC8-A
Abstract
Receptive fields of midget ganglion cells and parvocellular lateral geniculate nucleus (LGN) neurons show color-opponent responses because they receive antagonistic input from the middle- and long-wavelength sensitive cones. It has been controversial as to whether this opponency can derive from random connectivity; if receptive field centers of cells near the fovea are cone-specific due to midget morphology, this would confer some degree of color opponency even with random cone input to the surround. A simple test of this mixed surround hypothesis is to compare spatial frequency tuning curves for luminance gratings and gratings isolating cone input to the receptive field center. If tuning curves for luminance gratings were bandpass, then with the mixed surround hypothesis tuning curves for gratings isolating the receptive field center cone class should also be bandpass, but to a lesser extent than for luminance. Tuning curves for luminance, chromatic, and cone-isolating gratings were measured in macaque retinal ganglion cells and LGN cells. We defined and measured a bandpass index to compare luminance and center cone-isolating tuning curves. Midget retinal ganglion cells and parvocellular LGN cells had bandpass indices between 0.1 and 1 with luminance gratings, but the index was usually near 1 (meaning low-pass tuning) when the receptive field center cone class alone was modulated. This is strong evidence for a considerable degree of cone-specific input to the surround. A fraction of midget and parvocellular cells showed evidence of incomplete specificity. Fitting the data with receptive field models revealed considerable intercell variability, with indications in some cells of a more complex receptive structure than a simple difference of Gaussians model.