The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex.

The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex. Abstract Text:

Simple cells in primary visual cortex exhibit contrast-invariant orientation tuning, in seeming contradiction to feed-forward models that rely on lateral geniculate nucleus (LGN) input alone. Contrast invariance has therefore been thought to depend on the presence of intracortical lateral inhibition. In vivo intracellular recordings instead suggest that contrast invariance can be explained by three properties of the excitatory pathway. (1) Depolarizations evoked by orthogonal stimuli are determined by the amount of excitation a cell receives from the LGN, relative to the excitation it receives from other cortical cells. (2) Depolarizations evoked by preferred stimuli saturate at lower contrasts than the spike output of LGN relay cells. (3) Visual stimuli evoke contrast-dependent changes in trial-to-trial variability, which lead to contrast-dependent changes in the relationship between membrane potential and spike rate. Thus, high-contrast, orthogonally oriented stimuli that evoke significant depolarizations evoke few spikes. Together these mechanisms, without lateral inhibition, can account for contrast-invariant stimulus selectivity.

The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex. Publishing Authors By Initials

For similar nervous system: neural pathways: afferent pathways: visual pathways research abstracts see: nervous system: neural pathways: afferent pathways: visual pathways research

PUBMED ID PMID:

MEDLINE DATE:

The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex. Journal Published:

PUBLICATION TYPE: Research Support, N.I.H., Extr

Journal: Neuron

VOLUME: 54

Page Numbers: 137-52

Journal Abbreviation:

ISSN: 0896-6273

DAY: 5

MONTH: Apr

YEAR: 2007

The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 8809320

The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex. Keywords Mesh Terms:

KEYWORDS: Visual Pathways

MESH TERMS: physiology

Chemical & Substance for Abstract: The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex. Information

Substance Name:

Registry Number:

Grant and Affiliation Information for The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex.

AFFILIATION: Department of Neurobiology and Physiology, Northwestern University, 2205 Tech Drive, Evanston, IL 60208, USA.

Country: United States

AGENCY: United States NEI

GRANT: R01 EY04726

ACRONYM: EY

MEDLINETA: Neuron

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex Related Publications

• Computational diversity in complex cells of cat primary visual cortex.
• Inhibition, spike threshold, and stimulus selectivity in primary visual cortex.
• Magnetic resonance imaging and angiography in cerebral fungal vasculitis.
• Matched-related donor transplantation for sickle cell disease: report from the Center for International Blood and Transplant Research.
• The emergence of contrast-invariant orientation tuning in simple cells of cat visual cortex.
• Use of hydroxyurea in prevention of stroke in children with sickle cell disease.