Contextual Influences in V1 as a Basis
for Pop Out and Asymmetry in Visual Search
Zhaoping Li
Gatsby Computational Neuroscience Unit
University College London
Proceedings of National Academy of Science, USA Volumn 96, Number 18, 1999. Page
10530-10535
Abstract
I use a model to show how simple, bottom-up, neural mechanisms in
primary visual cortex can qualitatively explain the preattentive component of complex
psychophysical phenomena of visual search for a target among distracters. Depending on the
image features, the speed of search ranges from fast, when a target pops-out or is
instantaneously detectable, to very slow, and it can be asymmetric with respect to
switches between the target and distracter objects. It has been unclear which neural
mechanisms or even cortical areas control the ease of search, and no physiological
correlate has been found for search asymmetry. My model suggests that contextual
influences in V1 play a significant role.
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