The Challenges Natural Images Pose for Visual Adaptation

Rieke, Fred; Rudd, Michael E.

doi:10.1016/j.neuron.2009.11.028

Cited by 217 publications

(232 citation statements)

References 75 publications

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“…In the visual system, gain modulation adjusts neural responsiveness without impairing selectivity and is used to scale cortical network function in a contrast-dependent manner (33). Changes in input-output functions adjust firing rates to enhance coding of dynamic visual scenes where luminance, spatial frequency, and contrast often change over many orders of magnitude.…”

Section: Discussionmentioning

confidence: 99%

Overexpression of calcium-activated potassium channels underlies cortical dysfunction in a model of PTEN -associated autism

García-Junco-Clemente¹,

Chow²,

Tring³

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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De novo phosphatase and tensin homolog on chromosome ten (PTEN) mutations are a cause of sporadic autism. How single-copy loss of PTEN alters neural function is not understood. Here we report that Pten haploinsufficiency increases the expression of smallconductance calcium-activated potassium channels. The resultant augmentation of this conductance increases the amplitude of the afterspike hyperpolarization, causing a decrease in intrinsic excitability. In vivo, this change in intrinsic excitability reduces evoked firing rates of cortical pyramidal neurons but does not alter receptive field tuning. The decreased in vivo firing rate is not associated with deficits in the dendritic integration of synaptic input or with changes in dendritic complexity. These findings identify calcium-activated potassium channelopathy as a cause of cortical dysfunction in the PTEN model of autism and provide potential molecular therapeutic targets.gain | visual cortex | SK | mTOR | sensory processing

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Section: Discussionmentioning

confidence: 99%

Overexpression of calcium-activated potassium channels underlies cortical dysfunction in a model of PTEN -associated autism

García-Junco-Clemente¹,

Chow²,

Tring³

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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“…The visual system shows exact adaptation, as evidenced by experiments that track the eyes and accordingly move the visual field to cancel out these rapid eye movements, rendering the viewer unable to discern contrast within seconds (25)(26)(27). Vision also shows Weber's law to a good approximation across three decades of stimuli (28,29). Because vision exhibits both exact adaptation and Weber's law, it might also show FCD, a hypothesis that is experimentally testable.…”

Section: Fcd Entails Exact Adaptation and Weber's Law But Is Not Guarmentioning

confidence: 99%

Fold-change detection and scalar symmetry of sensory input fields

Shoval

Goentoro

Hart

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Recent studies suggest that certain cellular sensory systems display fold-change detection (FCD): a response whose entire shape, including amplitude and duration, depends only on fold changes in input and not on absolute levels. Thus, a step change in input from, for example, level 1 to 2 gives precisely the same dynamical output as a step from level 2 to 4, because the steps have the same fold change. We ask what the benefit of FCD is and show that FCD is necessary and sufficient for sensory search to be independent of multiplying the input field by a scalar. Thus, the FCD search pattern depends only on the spatial profile of the input and not on its amplitude. Such scalar symmetry occurs in a wide range of sensory inputs, such as source strength multiplying diffusing/convecting chemical fields sensed in chemotaxis, ambient light multiplying the contrast field in vision, and protein concentrations multiplying the output in cellular signaling systems. Furthermore, we show that FCD entails two features found across sensory systems, exact adaptation and Weber's law, but that these two features are not sufficient for FCD. Finally, we present a wide class of mechanisms that have FCD, including certain nonlinear feedback and feed-forward loops. We find that bacterial chemotaxis displays feedback within the present class and hence, is expected to show FCD. This can explain experiments in which chemotaxis searches are insensitive to attractant source levels. This study, thus, suggests a connection between properties of biological sensory systems and scalar symmetry stemming from physical properties of their input fields.adaptation | sensory response | spatial search O rganisms and cells sense their environment using sensory systems. Certain sensory systems have been extensively studied, and their input-output relations are well-characterized, including human senses, such as vision (1, 2), touch, and hearing, and unicellular senses, such as bacterial chemotaxis (3). Many sensory systems have common features. One such feature is exact adaptation in which the output to a change in input to a new constant level gradually returns to a level independent of the input. A second common feature, called Weber's law, states that the maximal response to a change in signal is inversely proportional to the background signal (4): Δy = kΔu/u 0 , where k is a constant, y is the output, and Δu is the signal change over the background u 0 . Weber's law in vision, chemotaxis, and other sensory systems applies over a range of several orders of magnitude of background input levels. Note that this definition stems from current practice that generalizes Weber's original measurements on psychophysical threshold sensitivity (4-7).Recent studies of the input-output properties of certain cellular signaling systems (8, 9) suggest that these systems show a feature called fold-change detection (FCD): a response whose entire shape, including its amplitude and duration, depends only on fold changes in input and not on absolute levels (10) (Fig. 1 A and...

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“…Regarding mechanisms, the spatiotemporal linear filter of the LN model is typically interpreted as mapping onto the aggregate sequential mechanisms of phototransduction, signal filtering and transmission through bipolar and amacrine cell pathways, and summation at the ganglion cell, while the nonlinearity is mapped onto the spiking threshold of ganglion cells. Regarding accuracy, while previous studies have found that these simple models can, for some neurons, capture most of the variance of the responses to low-resolution spatiotemporal white noise [9, 12, 20], they do not describe responses to stimuli with more structure such as natural scenes [13, 30–33]. …”

Section: Introductionmentioning

confidence: 99%

Inferring hidden structure in multilayered neural circuits

et al. 2018

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A central challenge in sensory neuroscience involves understanding how neural circuits shape computations across cascaded cell layers. Here we attempt to reconstruct the response properties of experimentally unobserved neurons in the interior of a multilayered neural circuit, using cascaded linear-nonlinear (LN-LN) models. We combine non-smooth regularization with proximal consensus algorithms to overcome difficulties in fitting such models that arise from the high dimensionality of their parameter space. We apply this framework to retinal ganglion cell processing, learning LN-LN models of retinal circuitry consisting of thousands of parameters, using 40 minutes of responses to white noise. Our models demonstrate a 53% improvement in predicting ganglion cell spikes over classical linear-nonlinear (LN) models. Internal nonlinear subunits of the model match properties of retinal bipolar cells in both receptive field structure and number. Subunits have consistently high thresholds, supressing all but a small fraction of inputs, leading to sparse activity patterns in which only one subunit drives ganglion cell spiking at any time. From the model’s parameters, we predict that the removal of visual redundancies through stimulus decorrelation across space, a central tenet of efficient coding theory, originates primarily from bipolar cell synapses. Furthermore, the composite nonlinear computation performed by retinal circuitry corresponds to a boolean OR function applied to bipolar cell feature detectors. Our methods are statistically and computationally efficient, enabling us to rapidly learn hierarchical non-linear models as well as efficiently compute widely used descriptive statistics such as the spike triggered average (STA) and covariance (STC) for high dimensional stimuli. This general computational framework may aid in extracting principles of nonlinear hierarchical sensory processing across diverse modalities from limited data.

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The Challenges Natural Images Pose for Visual Adaptation

Cited by 217 publications

References 75 publications

Overexpression of calcium-activated potassium channels underlies cortical dysfunction in a model of PTEN -associated autism

Overexpression of calcium-activated potassium channels underlies cortical dysfunction in a model of PTEN -associated autism

Fold-change detection and scalar symmetry of sensory input fields

Inferring hidden structure in multilayered neural circuits

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