Color Vision Sensitivity in Normally Dichromatic Species and Humans

Abstract

Spectral sensitivity functions for large, long-duration spectral stimuli presented on a photopic white background indicate that wavelength opponent mechanisms mediate detection of such stimuli in both normal and dichromatic humans. Normal humans detect the color of spectral flashes at detection threshold intensities, supporting the premise that wavelength opponent processes signal color. However, dichromatic humans do not see some colors at threshold; rather, they require stimuli up to about 0.4 log units above detection intensity. This suggests that dichiomatic humans may have a defect in postre- ceptoral color processing. To test this, we determined color discrimination thresholds in normally occurring dichromats, including the chipmunk, the 13-lined ground squirrel, and the tree shrew.

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Document Details

Document Type
Technical Report
Publication Date
Sep 23, 2002
Accession Number
ADA406727

Entities

People

  • Richard E. Van Arsdel

Organizations

  • Air Force Institute of Technology

Tags

DTIC Thesaurus Topics

  • Air Force
  • Cells
  • Color Vision
  • Detection
  • Institutional Review Board
  • Light Sources
  • Long Wavelengths
  • Medical Personnel
  • Neural Pathways
  • Optics
  • Physiology
  • Psychology
  • Psychophysiology
  • Reaction Time
  • Sensation
  • Sensitivity
  • Visible Spectra

Fields of Study

  • Biology

Readers

  • Aquatic Ecology
  • Vision Science/Vision Psychology/Cognitive Neuroscience.