RT Journal Article
SR Electronic
T1 Opposing Effects of Contextual Surround in Human Early Visual Cortex Revealed by Functional Magnetic Resonance Imaging with Continuously Modulated Visual Stimuli
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 3264
OP 3270
DO 10.1523/JNEUROSCI.4473-09.2010
VO 30
IS 9
A1 Tajima, Satohiro
A1 Watanabe, Masataka
A1 Imai, Chihiro
A1 Ueno, Kenichi
A1 Asamizuya, Takeshi
A1 Sun, Pei
A1 Tanaka, Keiji
A1 Cheng, Kang
YR 2010
UL http://www.jneurosci.org/content/30/9/3264.abstract
AB Spatial context in vision has profound effects on neural responses and perception. Recent animal studies suggest that the effect of surround on a central stimulus can dramatically change its character depending on the contrast of the center stimulus, but such a drastic change has not been demonstrated in the human visual cortex. To examine the dependency of the surround effect on the contrast of the center stimulus, we conducted an functional magnetic resonance imaging experiment by using a low or a high contrast in the center region while the surround contrast was sinusoidally modulated between the two contrasts. We found that the blood oxygen level-dependent response in human V1 corresponding to the center region was differentially modulated by the surround contrast, depending crucially on the center contrast: whereas a suppressive effect was observed in conditions in which the center contrast was high, a facilitative effect was seen in conditions where the center contrast was low.