A model for the intracortical origin of orientation preference and tuning in macaque striate cortex
| Autor: | Jennifer S. Lund, Jonathan B. Levitt, Peter Adorjan, Klaus Obermayer |
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| Rok vydání: | 1999 |
| Předmět: |
Physiology
media_common.quotation_subject Models Neurological Orientation (graph theory) Macaque Orientation biology.animal Geniculate Animals Contrast (vision) Computer Simulation Projection (set theory) Visual Cortex media_common Neurons biology Geniculate Bodies Models Theoretical Sensory Systems Preference Excitatory postsynaptic potential Macaca Nerve Net Striate cortex Psychology Neuroscience |
| Zdroj: | Visual Neuroscience. 16:303-318 |
| ISSN: | 1469-8714 0952-5238 |
| Popis: | We report results of numerical simulations for a model of generation of orientation selectivity in macaque striate cortex. In contrast to previous models, where the initial orientation bias is generated by convergent geniculate input to simple cells and subsequently sharpened by lateral circuits, our approach is based on anisotropic intracortical excitatory connections which provide both the initial orientation bias and its subsequent amplification. Our study shows that the emerging response properties are similar to the response properties that are observed experimentally, hence the hypothesis of an intracortical generation of orientation bias is a sensible alternative to the notion of an afferent bias by convergent geniculocortical projection patterns. In contrast to models based on an afferent orientation bias, however, the “intracortical hypothesis” predicts that orientation tuning gradually evolves from an initially nonoriented response and a complete loss of orientation tuning when the recurrent excitation is blocked, but new experiments must be designed to unambiguously decide between both hypotheses. |
| Databáze: | OpenAIRE |
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