Contextual effects by short range connections in a mean-field model of Vi

摘要

In this paper, we derive a model for analyzing the influence of local cortical connectios on the activities of neurons in vl. A set of orientation columns is arranged according to a mea- sured orientation map. Orientation columns are connected by local excitatory and slightly more distributed inhibitory fibers. Based on this geometrical model we demonstrate that (i) sharp and contrast-invariant orientation tuning curves are combined with contrast satura tion, (ii) the strength of cortical amplification can be localized in orientation space and (iii)anisotropic contextual suppression by iso-oriented flanking stimuli arises as an emergent property and can be mediated by local connection.