scholarly journals Model-based characterization of the selectivity of neurons in primary visual cortex

2021 ◽  
Author(s):  
Felix Bartsch ◽  
Bruce G Cumming ◽  
Daniel A Butts
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Primary Visual Cortex ◽  
Visual Processing ◽  
Frequency Tuning ◽  
Nonlinear Models ◽  
Field Size ◽  
V1 Neurons ◽  
Model Based ◽  
Spatial Frequencies

To understand the complexity of stimulus selectivity in primary visual cortex (V1), models constructed to match observed responses to complex time-varying stimuli, instead of to explain responses to simple parametric stimuli, are increasingly used. While such models often can more accurately reflect the computations performed by V1 neurons in more natural visual environments, they do not by themselves provide insight into established measures of V1 neural selectivity such as receptive field size, spatial frequency tuning and phase invariance. Here, we suggest a series of analyses that can be directly applied to encoding models to link complex encoding models to more interpretable aspects of stimulus selectivity, applied to nonlinear models of V1 neurons recorded in awake macaque in response to random bar stimuli. In linking model properties to more classical measurements, we demonstrate several novel aspects of V1 selectivity not available to simpler experimental measurements. For example, we find that individual spatiotemporal elements of the V1 models often have a smaller spatial scale than the overall neuron sensitivity, and that this results in non-trivial tuning to spatial frequencies. Additionally, our proposed measures of nonlinear integration suggest that more classical classifications of V1 neurons into simple versus complex cells are spatial-frequency dependent. In total, rather than obfuscate classical characterizations of V1 neurons, model-based characterizations offer a means to more fully understand their selectivity, and provide a means to link their classical tuning properties to their roles in more complex, natural, visual processing.

Cortical Maps of Separable Tuning Properties Predict Population Responses to Complex Visual Stimuli

2005 ◽  
Vol 94 (1) ◽  
pp. 775-787 ◽  
Author(s):  
Tanya I. Baker ◽  
Naoum P. Issa
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Primary Visual Cortex ◽  
Visual Processing ◽  
Frequency Tuning ◽  
Temporal Frequency ◽  
Sinusoidal Grating ◽  
Cortical Organization ◽  
Moving Images ◽  
Spatial Parameters

In the earliest cortical stages of visual processing, a scene is represented in different functional domains selective for specific features. Maps of orientation and spatial frequency preference have been described in the primary visual cortex using simple sinusoidal grating stimuli. However, recent imaging experiments suggest that the maps of these two spatial parameters are not sufficient to describe patterns of activity in different orientation domains generated in response to complex, moving stimuli. A model of cortical organization is presented in which cortical temporal frequency tuning is superimposed on the maps of orientation and spatial frequency tuning. The maps of these three tuning properties are sufficient to describe the activity in orientation domains that have been measured in response to drifting complex images. The model also makes specific predictions about how moving images are represented in different spatial frequency domains. These results suggest that the tangential organization of primary visual cortex can be described by a set of maps of separable neuronal receptive field features including maps of orientation, spatial frequency, and temporal frequency tuning properties.

scholarly journals Mapping Spatial Frequency Preferences Across Human Primary Visual Cortex

2021 ◽  
Author(s):  
William F. Broderick ◽  
Eero P. Simoncelli ◽  
Jonathan Winawer
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Spatial Frequency ◽  
Primary Visual Cortex ◽  
Frequency Tuning ◽  
Tuning Curve ◽  
Stimulus Orientation ◽  
Polar Coordinates ◽  
Small Constant ◽  
Spatial Frequencies

AbstractNeurons in primate visual cortex (area V1) are tuned for spatial frequency, in a manner that depends on their position in the visual field. Several studies have examined this dependency using fMRI, reporting preferred spatial frequencies (tuning curve peaks) of V1 voxels as a function of eccentricity, but their results differ by as much as two octaves, presumably due to differences in stimuli, measurements, and analysis methodology. Here, we characterize spatial frequency tuning at a millimeter resolution within human primary visual cortex, across stimulus orientation and visual field locations. We measured fMRI responses to a novel set of stimuli, constructed as sinusoidal gratings in log-polar coordinates, which include circular, radial, and spiral geometries. For each individual stimulus, the local spatial frequency varies inversely with eccentricity, and for any given location in the visual field, the full set of stimuli span a broad range of spatial frequencies and orientations. Over the measured range of eccentricities, the preferred spatial frequency is well-fit by a function that varies as the inverse of the eccentricity plus a small constant. We also find small but systematic effects of local stimulus orientation, defined in both absolute coordinates and relative to visual field location. Specifically, peak spatial frequency is higher for tangential than radial orientations and for horizontal than vertical orientations.

scholarly journals Flow stimuli reveal ecologically-appropriate responses in mouse visual cortex

2018 ◽  
Author(s):  
Luciano Dyballa ◽  
Mahmood S. Hoseini ◽  
Maria C. Dadarlat ◽  
Steven W. Zucker ◽  
Michael P. Stryker
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Visual System ◽  
Primary Visual Cortex ◽  
Frequency Analysis ◽  
Visual Processing ◽  
Temporal Frequency ◽  
Natural World ◽  
Spatial Frequencies ◽  
Spatial Frequency Analysis

AbstractAssessments of the mouse visual system based on spatial frequency analysis imply that its visual capacity is low, with few neurons responding to spatial frequencies greater than 0.5 cycles/degree. However, visually-mediated behaviors, such as prey capture, suggest that the mouse visual system is more precise. We introduce a new stimulus class—visual flow patterns—that is more like what the mouse would encounter in the natural world than are sine-wave gratings but is more tractable for analysis than are natural images. We used 128-site silicon microelectrodes to measure the simultaneous responses of single neurons in the primary visual cortex (V1) of alert mice. While holding temporal-frequency content fixed, we explored a class of drifting patterns of black or white dots that have energy only at higher spatial frequencies. These flow stimuli evoke strong visually-mediated responses well beyond those predicted by spatial frequency analysis. Flow responses predominate in higher spatial-frequency ranges (0.15–1.6 cycles/degree); many are orientation- or direction-selective; and flow responses of many neurons depend strongly on sign of contrast. Many cells exhibit distributed responses across our stimulus ensemble. Together, these results challenge conventional linear approaches to visual processing and expand our understanding of the mouse’s visual capacity to behaviorally-relevant ranges.Significance StatementThe visual system of the mouse is now widely studied as a model for development and disease in humans. Studies of its primary visual cortex (V1) using conventional grating stimuli to construct linear-nonlinear receptive fields suggest that the mouse must have very poor vision. Using novel stimuli resembling the flow of images across the retina as the mouse moves through the grass, we find that most V1 neurons respond reliably to very much finer details of the visual scene than previously believed. Our findings suggest that the conventional notion of a unique receptive field does not capture the operation of the neural network in mouse V1.

scholarly journals Dynamics of spatial frequency tuning in mouse visual cortex

2012 ◽  
Vol 107 (11) ◽  
pp. 2937-2949 ◽  
Author(s):  
Samme Vreysen ◽  
Bin Zhang ◽  
Yuzo M. Chino ◽  
Lutgarde Arckens ◽  
Gert Van den Bergh
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Visual Information ◽  
Frequency Tuning ◽  
Neuronal Response ◽  
Correlation Technique ◽  
Low Frequencies ◽  
Temporal Shift ◽  
Spatial Frequency Tuning ◽  
Spatial Frequencies

Neuronal spatial frequency tuning in primary visual cortex (V1) substantially changes over time. In both primates and cats, a shift of the neuron's preferred spatial frequency has been observed from low frequencies early in the response to higher frequencies later in the response. In most cases, this shift is accompanied by a decreased tuning bandwidth. Recently, the mouse has gained attention as a suitable animal model to study the basic mechanisms of visual information processing, demonstrating similarities in basic neuronal response properties between rodents and highly visual mammals. Here we report the results of extracellular single-unit recordings in the anesthetized mouse where we analyzed the dynamics of spatial frequency tuning in V1 and the lateromedial area LM within the lateral extrastriate area V2L. We used a reverse-correlation technique to demonstrate that, as in monkeys and cats, the preferred spatial frequency of mouse V1 neurons shifted from low to higher frequencies later in the response. However, this was not correlated with a clear selectivity increase or enhanced suppression of responses to low spatial frequencies. These results suggest that the neuronal connections responsible for the temporal shift in spatial frequency tuning may considerably differ between mice and monkeys.

Spatial Frequency-Specific Contrast Adaptation Originates in the Primary Visual Cortex

2007 ◽  
Vol 98 (1) ◽  
pp. 187-195 ◽  
Author(s):  
Thang Duong ◽  
Ralph D. Freeman
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Frequency Tuning ◽  
Adaptation Effect ◽  
Tuning Curves ◽  
Contrast Adaptation ◽  
Spatial Frequencies ◽  
Neurophysiological Studies ◽  
High Contrast Grating ◽  
Adaptation Effects

Adaptation to a high-contrast grating stimulus causes reduced sensitivity to subsequent presentation of a visual stimulus with similar spatial characteristics. This behavioral finding has been attributed by neurophysiological studies to processes within the visual cortex. However, some evidence indicates that contrast adaptation phenomena are also found in early visual pathways. Adaptation effects have been reported in retina and lateral geniculation nucleus (LGN). It is possible that these early pathways could be the physiological origin of the cortical adaptation effect. To study this, we recorded from single neurons in the cat's LGN. We find that contrast adaptation in the LGN, unlike that in the visual cortex, is not spatial frequency specific, i.e., adaptation effects apply to a broad range of spatial frequencies. In addition, aside from the amplitude attenuation, the shape of spatial frequency tuning curves of LGN cells is not affected by contrast adaptation. Again, these findings are unlike those found for cells in the visual cortex. Together, these results demonstrate that pattern specific contrast adaptation is a cortical process.

scholarly journals Superior colliculus encodes visual saliency before the primary visual cortex

2017 ◽  
Vol 114 (35) ◽  
pp. 9451-9456 ◽  
Author(s):  
Brian J. White ◽  
Janis Y. Kan ◽  
Ron Levy ◽  
Laurent Itti ◽  
Douglas P. Munoz
Keyword(s):  
Visual Cortex ◽  
Superior Colliculus ◽  
Primary Visual Cortex ◽  
Visual Processing ◽  
Visual Saliency ◽  
Saliency Map ◽  
Stimulus Onset ◽  
Brain Areas ◽  
V1 Neurons ◽  
Processing Stream

Models of visual attention postulate the existence of a bottom-up saliency map that is formed early in the visual processing stream. Although studies have reported evidence of a saliency map in various cortical brain areas, determining the contribution of phylogenetically older pathways is crucial to understanding its origin. Here, we compared saliency coding from neurons in two early gateways into the visual system: the primary visual cortex (V1) and the evolutionarily older superior colliculus (SC). We found that, while the response latency to visual stimulus onset was earlier for V1 neurons than superior colliculus superficial visual-layer neurons (SCs), the saliency representation emerged earlier in SCs than in V1. Because the dominant input to the SCs arises from V1, these relative timings are consistent with the hypothesis that SCs neurons pool the inputs from multiple V1 neurons to form a feature-agnostic saliency map, which may then be relayed to other brain areas.

scholarly journals Dynamic distortion of the orientation representational space after learning in the mouse primary visual cortex

2021 ◽  
Author(s):  
Julien Corbo ◽  
John P McClure ◽  
Orhan Batuhan Erkat ◽  
Pierre-Olivier Polack
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Processing ◽  
Sensory Integration ◽  
Orientation Discrimination ◽  
Stimulus Generalization ◽  
Behavioral Adaptation ◽  
V1 Neurons ◽  
Orientation Space ◽  
Representational Space

Learning is an essential cognitive mechanism that supports behavioral adaptation through neural processing adjustments. Learning was shown to modify sensory integration, yet the nature of those modifications and the computational advantages they confer remain unclear. By comparing the responses of primary visual cortex (V1) neurons evoked by oriented stimuli in naive mice and mice performing an orientation discrimination task, we found that the representations of rewarded and non-rewarded cues were sparser, more accurate and more stable in trained mice. This improved representation was associated with a distortion of the V1 orientation space such that stimuli close to the task cues were represented as the task stimuli themselves. This distortion was context-dependent, as it was absent in trained mice passively viewing the cues. Hence, visual processing in V1 was dynamically adapted to enhance the reliability of the representation of the learned cues and favor stimulus generalization in the task-relevant computational space.

scholarly journals Inseparable color and form in mouse visual cortex described by random pooling from rods and cones

2021 ◽  
Author(s):  
Issac Rhim ◽  
Ian Nauhaus
Keyword(s):  
Visual Cortex ◽  
Frequency Tuning ◽  
Green Light ◽  
Brightness Contrast ◽  
Color Contrast ◽  
V1 Neurons ◽  
Rods And Cones ◽  
Spatial Frequencies ◽  
Mouse Visual Cortex ◽  
Minimal Constraints

An image projected onto the retina is composed of local contrasts in color and brightness, both of which can aid in any visual perception task. Recent investigations of the mouse ventral retina demonstrate that rod and cone responses are combined to detect changes between UV and green light, thus providing a new model for color vision. An important question is how the spatial representations of both color and brightness contrast are transformed by downstream circuits. Its known that SF tuning of brightness contrast is sharpened at the level of mouse primary visual cortex, yet color contrast is untested. Here, we presented sinewave gratings that drive one of four axes of rod and cone contrast space, including brightness contrast (rod+cone) and color contrast (rod-cone). We find that V1 neurons are tuned to higher spatial frequencies of brightness contrast than color contrast, and are most responsive to color at the lowest spatial frequencies. These results are consistent with a model of single-opponency between rods and cones, but do not match its classic description. The data can instead be described by a simple model of convergent ON and OFF inputs to V1, which randomly pool discrete quantities of each photoreceptor class. Unlike classic depictions of single-opponency, this model requires minimal constraints on the circuit, accounts for our observed bandpass spatial frequency tuning of rod and cone isolating contrast, and is consistent with recent studies showing unselective pooling from photoreceptors in the retina.

scholarly journals Flow stimuli reveal ecologically appropriate responses in mouse visual cortex

2018 ◽  
Vol 115 (44) ◽  
pp. 11304-11309 ◽  
Author(s):  
Luciano Dyballa ◽  
Mahmood S. Hoseini ◽  
Maria C. Dadarlat ◽  
Steven W. Zucker ◽  
Michael P. Stryker
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Visual System ◽  
Frequency Analysis ◽  
Visual Processing ◽  
Prey Capture ◽  
Temporal Frequency ◽  
Natural World ◽  
Spatial Frequencies ◽  
Spatial Frequency Analysis

Assessments of the mouse visual system based on spatial-frequency analysis imply that its visual capacity is low, with few neurons responding to spatial frequencies greater than 0.5 cycles per degree. However, visually mediated behaviors, such as prey capture, suggest that the mouse visual system is more precise. We introduce a stimulus class—visual flow patterns—that is more like what the mouse would encounter in the natural world than are sine-wave gratings but is more tractable for analysis than are natural images. We used 128-site silicon microelectrodes to measure the simultaneous responses of single neurons in the primary visual cortex (V1) of alert mice. While holding temporal-frequency content fixed, we explored a class of drifting patterns of black or white dots that have energy only at higher spatial frequencies. These flow stimuli evoke strong visually mediated responses well beyond those predicted by spatial-frequency analysis. Flow responses predominate in higher spatial-frequency ranges (0.15–1.6 cycles per degree), many are orientation or direction selective, and flow responses of many neurons depend strongly on sign of contrast. Many cells exhibit distributed responses across our stimulus ensemble. Together, these results challenge conventional linear approaches to visual processing and expand our understanding of the mouse’s visual capacity to behaviorally relevant ranges.

Stimulus dependence of orientation and direction sensitivity of cat LGNd relay cells without cortical inputs: A comparison with area 17 cells

1994 ◽  
Vol 11 (5) ◽  
pp. 939-951 ◽  
Author(s):  
Kirk G. Thompson ◽  
Audie G. Leventhal ◽  
Yifeng Zhou ◽  
Dan Liu
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Frequency Tuning ◽  
Area 17 ◽  
Cortical Cells ◽  
Spatial Frequency Tuning ◽  
Spatial Frequencies ◽  
Direction Sensitivity ◽  
Cortical Inputs ◽  
Direction Tuning

AbstractThe cortical contribution to the orientation and direction sensitivity of LGNd relay cells was investigated by recording the responses of relay cells to drifting sinusoidal gratings of varying spatial frequencies, moving bars, and moving spots in cats in which the visual cortex (areas 17, 18, 19, and LS) was ablated. For comparison, the spatial-frequency dependence of orientation and direction tuning of striate cortical cells was investigated employing the same quantitative techniques used to test LGNd cells. There are no significant differences in the orientation and direction tuning to relay cells in the LGNd of normal and decorticate cats. The orientation and direction sensitivities of cortical cells are dependent on stimulus parameters in a fashion qualitatively similar to that of LGNd cells. The differences in the spatial-frequency bandwidths of LGNd cells and cortical cells may explain many of their differences in orientation and direction tuning. Although factors beyond narrowness of spatial-frequency tuning must exist to account for the much stronger orientation and direction preferences of cells in area 17 when compared to LGNd cells, the evidence suggests that the orientation and direction biases present in the afferents to the visual cortex may contribute to the orientation and direction selectivities found in cortical cells.

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