Afterimage of Perceptually Filled-in Surface
Shinsuke Shimojo,12*
Yukiyasu Kamitani,1
Shin'ya Nishida2
An afterimage induced by prior adaptation to a visual stimulus is
believed to be due to bleaching of photochemical pigments or neural
adaptation in the retina. We report a type of afterimage that appears
to require cortical adaptation. Fixating a neon-color spreading
configuration led not only to negative afterimages corresponding to the
inducers (local afterimages), but also to one corresponding to the
perceptually filled-in surface during adaptation (global afterimage).
These afterimages were mutually exclusive, undergoing monocular
rivalry. The strength of the global afterimage correlated to a greater
extent with perceptual filling-in during adaptation than with the
strength of the local afterimages. Thus, global afterimages are not
merely by-products of local afterimages, but involve adaptation at a
cortical representation of surface.
1 California Institute of Technology, Division
of Biology, Computation and Neural Systems, Pasadena, CA, 91125, USA.
2 NTT Corporation, NTT Communication
Science Laboratories, Human and Information Science Laboratory, Atsugi,
Kanagawa, 243-0198, Japan.
*
To whom correspondence should be addressed. E-mail:
sshimojo{at}its.caltech.edu
