A Retinal Source of Spatial Contrast Gain Control
نویسندگان
چکیده
منابع مشابه
A retinal source of spatial contrast gain control.
Sensory cortex is able to encode a broad range of stimulus features despite a great variation in signal strength. In cat primary visual cortex (V1), for example, neurons are able to extract stimulus features like orientation or spatial configuration over a wide range of stimulus contrasts. The contrast-invariant spatial tuning found in V1 neuron responses has been modeled as a gain control mech...
متن کاملSimulation of Retinal Contrast Gain Control Mechanisms
I present a simulation of contrast gain control mechanisms operating among transient M cells in the monkey s retina in order to investigate the spatial consequences of this interaction The simulation stages include a realistic viewing model non linear receptor model linear spatial ltering and a saturating output function Contrast gain control is introduced by pooling recti ed signals from on an...
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We report psychophysical measurements of spatial pooling functions for contrast gain control. We use a nulling technique to measure the dependence of contrast induction on the spatial frequency of a sinusoidal contrast modulation. This dependence on spatial frequency, when transformed, provides the profile of a spatial pooling function. The measured profiles are fitted well by Gaussians. We con...
متن کاملNonlinear spatial summation and the contrast gain control of cat retinal ganglion cells.
1. We studied how responses to visual stimuli at spatially separated locations were combined by cat retinal ganglion cells. 2. The temporal signal which modulated the stimuli was a sum of sinusoids. Fourier analysis of the ganglion cell impulse train yielded first order responses at the modulation frequencies, and second order responses at sums and differences of the input frequencies. 3. Spati...
متن کاملDistinct expressions of contrast gain control in parallel synaptic pathways converging on a retinal ganglion cell.
Visual neurons adapt to increases in stimulus contrast by reducing their response sensitivity and decreasing their integration time, a collective process known as 'contrast gain control.' In retinal ganglion cells, gain control arises at two stages: an intrinsic mechanism related to spike generation, and a synaptic mechanism in retinal pathways. Here, we tested whether gain control is expressed...
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ژورنال
عنوان ژورنال: Journal of Neuroscience
سال: 2012
ISSN: 0270-6474,1529-2401
DOI: 10.1523/jneurosci.0207-12.2012