Surround Suppression
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Modulação centro-contorno em campos receptivos do wulst visual
Neurons in the primary visual cortex (V1) typically show response suppression when stimulated by oriented stimuli larger than their classical receptive fields (CRF). Here, we investigate the prevalence, strength and feature selectivity of center-surround modulation in the owl visual wulst, an area that presents close hodological and physiological similaritie
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/10/2011
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2. Utilização de equações diferenciais parciais para eliminação de ruídos e detecção de bordas
The edge detection of digital images is a research field that has attracted great interest from the scientific community. Their applications go from the automatic inspection and quality control of industrial piece to the diagnosis of malignancy of cancerous tumors. However, many existing edge detectors have problems related to false edge detection. In this c
Publicado em: 2008
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3. Diminished Orientation-Specific Surround Suppression of Visual Processing in Schizophrenia
Visual perception of a stimulus is a function of the visual context in which it is displayed. Surround suppression is a specific form of contextual modulation whereby the perceived contrast of a center stimulus is decreased by a high-contrast surround. Recent studies have demonstrated that individuals with schizophrenia are less prone to visual contextual ef
Oxford University Press.
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4. Comparison of Spatial Summation Properties of Neurons in Macaque V1 and V2
In visual cortex, responses to stimulation of the receptive field (RF) are modulated by simultaneous stimulation of the RF surround. The mechanisms for surround modulation remain unidentified. We previously proposed that in the primary visual cortex (V1), near surround modulation is mediated by geniculocortical and horizontal connections and far surround mod
American Physiological Society.
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5. Subthreshold facilitation and suppression in primary visual cortex revealed by intrinsic signal imaging.
Neurons in primary visual cortex (area 17) respond vigorously to oriented stimuli within their receptive fields; however, stimuli presented outside the suprathreshold receptive field can also influence their responses. Here we describe a fundamental feature of the spatial interaction between suprathreshold center and subthreshold surround. By optical imaging
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6. Surround Motion Silences Signals From Same-Direction Motion
The response of motion-sensitive neurons to stimuli presented within their receptive field is often affected by stimulation in the surrounding region. These effects have perceptually relevant consequences that can be measured using behavioral techniques. We used psychophysical reverse correlation to characterize directional selectivity in human observers whi
American Physiological Society.
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7. Effects of 2-amino-4-phosphonobutyric acid on responsivity and spatial summation of X cells in the cat retina.
1. We studied the effect of locally applied 2-amino-4-phosphonobutyric acid (APB) on the response of X-type cat retinal ganglion cells to stimulation by sinusoidal gratings of photopic mean luminance. 2. Application of APB produced a decrease in the mean firing rate of on-centre X cells, but an increase in the mean firing rate of off-centre X cells. 3. The r
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8. Effects of picrotoxin and strychnine on non-linear responses of Y-type cat retinal ganglion cells.
1. The effects of neurotransmitter antagonists on spatially linear and non-linear responses of Y cat retinal ganglion cells were studied. 2. The contrast sensitivity of the spatially linear receptive field centre and surround at mesopic and photopic levels of illumination was affected very little by picrotoxin, but the sensitivity of the non-linear subunits
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9. Interactions between the PAS and HAMP Domains of the Escherichia coli Aerotaxis Receptor Aer
The Escherichia coli energy-sensing Aer protein initiates aerotaxis towards environments supporting optimal cellular energy. The Aer sensor is an N-terminal, FAD-binding, PAS domain. The PAS domain is linked by an F1 region to a membrane anchor, and in the C-terminal half of Aer, a HAMP domain links the membrane anchor to the signaling domain. The F1 region,
American Society for Microbiology.
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10. Effects of gamma-aminobutyric acid on isolated cone photoreceptors of the turtle retina.
Isolated cones dissociated from the retina of the freshwater turtle were voltage clamped using a single 'patch' pipette electrode. gamma-Aminobutyric acid (GABA) applied ionophoretically to the axon terminal evoked an inward current in cells held at -66 mV when they were recorded with patch pipettes filled with the 'control' pipette solution containing 120 m
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11. Noradrenergic modulation of retinogeniculate transmission in the cat.
1. Relay neurones were extracellularly recorded from the A-layers of the dorsal lateral geniculate nucleus (dLGN) of the anaesthetized cat. The noradrenergic influence on retinogeniculate transmission was investigated through microiontopheretic techniques in a total of 140 dLGN relay cells using three experimental approaches: (i) the effects of agonists for