Abstract

Principal-component analysis was used to find an optimum set of orthonormal basis vectors that could span the chromatic space of cone spectra in the human eye. The Smith and Pokorny cone spectra¹ were used, weighted by the percentages of the various cone pigment types in the monkey fovea and raised to the 1/3 power to account for response compression. The eigenvectors of these cone spectra were then orthogonally rotated into the macaque monkey lateral geniculate nucleus (LGN) eigenvectors² using the optimum least-squares rotation matrix. The second (biphasic) vector had to be reflected as well as rotated. The correlations of the rotated human cone vectors with the monkey LGN vectors were 0.98, 0.99, and 0.92, indicating close correspondence between the principal axes of human cones and monkey LGN cells. Indeed, since all relative distances and angles between points in a space are preserved by an orthogonal rotation, it can be concluded that human tricone chromatic space and monkey LGN cell chromatic space are formally congruent.

© 1987 Optical Society of America