Submitted on September 5, 2007
Accepted on May 27, 2008
V1 Response Timing and Surface Filling-In
Xin Huang1 and Michael A Paradiso1*
1 Neuroscience, Brown University, Providence, Rhode Island, United States
* To whom correspondence should be addressed. E-mail: michael_paradiso{at}brown.edu.
There is ample evidence from demonstrations such as color induction and stabilized images that information from surface boundaries plays a special role in determining the perception of surface interiors. Surface interiors appear to "fill-in". Psychophysical experiments also show that surface perception involves a slow scale-dependent process distinct from mechanisms involved in contour perception. The present experiments aimed to test the hypothesis that surface perception is associated with relatively slow scale-dependent neural filling-in. We found that responses in macaque V1 are slower to surface interiors than responses to optimal bar stimuli. Moreover, we found that the response to a surface interior is delayed relative to the response to the surface’s border and the extent of the delay is proportional to the distance between a receptive field and the border. These findings are consistent with neural filling-in and suggest that V1 may provide the neural substrate for perceptual filling-in.
