Two experiments examined interocular transfer for simple and dynamic aftere
ffects of density and contrast. Simple aftereffects of texture contrast wer
e shown to be primarily monocular. Texture density aftereffects were shown
to be primarily binocular. Similarly, dynamic aftereffects to repeated chan
ges in contrast were found to be completely monocular; those to repeated ch
anges in density were found to be entirely binocular. Since contrast and de
nsity aftereffects differ in their sensitivity to eye-of-origin, they likel
y depend on different neural loci, and are not manifestations of the same u
nderlying adaptation. Consistent with this conclusion, it is proposed that.
whereas contrast normalization (and perhaps contrast aftereffects) may be
localized to simple cells in Vl, density coding and normalization require c
omputations only available in complex cells and beyond. (C) 2001 Elsevier S
cience Ltd. All rights reserved.