Yeshurun, Y. & Carrasco, M.
(2000) The locus of attentional effects in texture segmentation. Nature
Neuroscience, 3 (6): 622-627.
Cuing covert spatial attention can increase spatial resolution. Here we
pinpointed the specific locus of this effect using texture segmentation.
At the level of visual cortex, texture segmentation theoretically involves
passage of visual input through two layers of spatial linear filters separated
by a pointwise non-linearity. By manipulating the textures to differentially
stimulate first- or second-order filters of various scales, we showed
that the attentional effect consistently varied with the latter. These
psychophysical results further support the hypothesis that attention increases
resolution at the attended location and are consistent with an effect
of attention at stages as early as the primary visual cortex.