On the anatomical basis of field size, contrast sensitivity, and orientation selectivity in macaque striate cortex: A model study

Rearing cats with esotropia is known to cause a number of deficits in visual behavior tested through the deviated eye. These include a loss of orienting response to stimuli presented in the nasal visual field of the deviated eye, a reduction in visual acuity, and a general reduction in contrast sensitivity at all spatial frequencies. To assess the involvement of the lateral geniculate nucleus (LGN) in these deficits, we measured the following: 1) the visual responsiveness of lamina A1 cells with peripheral (more than 10 degrees from area centralis) receptive fields in three esotropic and three normal cats and 2) the spatial resolution and contrast sensitivity of lamina A X-cells with central (within 5 degrees of the area centralis) receptive fields in six esotropic and six normal cats. For comparison, we also measured LGN X-cell spatial resolutions in four exotropic cats and in two cats raised with an esotropia in one eye and the lids of the other eye sutured shut (MD-estropes). Recordings from the lateral portion of lamina A1 in esotropic cats yielded similar numbers of visually responsive cells with far nasal receptive fields as were seen in normal animals. Peak and mean response rates to a flashing spot also were normal. In addition, no differences were found between esotropes and normals in the percentages of X- and Y-cells encountered. These results suggest that the loss of orienting response to stimuli presented in the nasal field (12, 20) is not due to a loss of neural responses in the LGN of esotropic cats. In addition, they suggest that decreases in cell size in lamina A1 of esotropic cats (13, 36; R. E. Kalil, unpublished observations) are not accompanied by marked functional abnormalities of the cells and that cortical abnormalities ipsilateral to the deviated eye (22) are likely to have their origin within striate cortex itself. Recordings from lamina A cells with receptive fields near area centralis revealed that the average X-cell spatial resolution in esotropes (2.1 cycles/deg) was significantly lower than that in normal cats (3.1 cycles/deg). This reduction was seen in all esotropic cats tested and was due both to an increase in the proportion of X-cells with very low spatial resolution and to a loss of X-cells responding to high spatial frequencies (greater than 3.25 cycles/deg). The average spatial resolution of X-cells driven by the deviated eye in MD-esotropes fell midway between those of esotropes and normals. In exotropes, mean X-cell spatial resolution was normal.(ABSTRACT TRUNCATED AT 400 WORDS)

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Neural motion after-effects in the cat's striate cortex: Orientation selectivity

Vision Research ◽

10.1016/0042-6989(89)90149-1 ◽

1989 ◽

Vol 29 (12) ◽

pp. 1671-1683 ◽

Cited By ~ 18

Author(s):

P. Hammond ◽

C.J.D. Pomfrett ◽

B. Ahmed

Keyword(s):

Striate Cortex ◽

Orientation Selectivity ◽

After Effects

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Spatial receptive-field properties of direction-selective neurons in cat striate cortex

Journal of Neurophysiology ◽

10.1152/jn.1986.55.6.1136 ◽

1986 ◽

Vol 55 (6) ◽

pp. 1136-1152 ◽

Cited By ~ 62

Author(s):

C. L. Baker ◽

M. S. Cynader

Keyword(s):

Receptive Field ◽

Striate Cortex ◽

Weighting Function ◽

Direction Selectivity ◽

Field Size ◽

Spatial Period ◽

Sinusoidal Grating ◽

Subunit Structure ◽

Receptive Field Size ◽

Cat Striate Cortex

Responses of direction-selective neurons in cat striate cortex (area 17) were studied with flashed-bar stimuli. Spatial parameters of interactions within the receptive field giving rise to direction selectivity and of receptive-field subunits were quantitatively determined for the same cells and correlated. A bar stimulus flashed sequentially at two nearby locations in the receptive field produced direction-selective behavior comparable with that elicited by continuously moving stimuli. Each cell exhibited a characteristic optimal spatial displacement, Dopt, for which responses in the presumed preferred and null directions were maximally distinct. In all cases, Dopt was much smaller than the receptive-field size. The spatial structure of receptive fields in simple cells was studied using single narrow-bar stimuli flashed at different locations in the receptive field. The resulting line-weighting function exhibited alternating regions of ON and OFF responses having a characteristic spatial period or wavelength, lambda. Spatial subunit structure in complex cells was determined by flashing two bars simultaneously in the receptive field. The response as a function of bar separation was again a wavelike function having a spatial wavelength, lambda. Values of the optimal displacement for direction selectivity, Dopt, showed a clear relationship with the spatial wavelength, lambda, for a given unit. Dopt was also correlated to a somewhat lesser degree with receptive-field size. Generally, the ratio of Dopt to lambda was approximately 1/10 to 1/4, in agreement with theoretical predictions by Marr and Poggio. Taken together with the findings of Movshon et al., these results indicate a systematic relationship between Dopt and the spatial frequency of a sinusoidal grating, which is optimal for that cell. Such a relationship is consistent with the results of human psychophysical experiments on apparent motion.

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Receptive-field characteristics of neurons in cat striate cortex: Changes with visual field eccentricity

Journal of Neurophysiology ◽

10.1152/jn.1976.39.3.512 ◽

1976 ◽

Vol 39 (3) ◽

pp. 512-533 ◽

Cited By ~ 97

Author(s):

J. R. Wilson ◽

S. M. Sherman

Keyword(s):

Visual Field ◽

Receptive Field ◽

Striate Cortex ◽

Ocular Dominance ◽

Receptive Fields ◽

Direction Selectivity ◽

Orientation Selectivity ◽

Simple Cells ◽

Complex Cells ◽

Cat Striate Cortex

1. Receptive-field properties of 214 neurons from cat striate cortex were studied with particular emphasis on: a) classification, b) field size, c) orientation selectivity, d) direction selectivity, e) speed selectivity, and f) ocular dominance. We studied receptive fields located throughtout the visual field, including the monocular segment, to determine how receptivefield properties changed with eccentricity in the visual field.2. We classified 98 cells as "simple," 80 as "complex," 21 as "hypercomplex," and 15 in other categories. The proportion of complex cells relative to simple cells increased monotonically with receptive-field eccenticity.3. Direction selectivity and preferred orientation did not measurably change with eccentricity. Through most of the binocular segment, this was also true for ocular dominance; however, at the edge of the binocular segment, there were more fields dominated by the contralateral eye.4. Cells had larger receptive fields, less orientation selectivity, and higher preferred speeds with increasing eccentricity. However, these changes were considerably more pronounced for complex than for simple cells.5. These data suggest that simple and complex cells analyze different aspects of a visual stimulus, and we provide a hypothesis which suggests that simple cells analyze input typically from one (or a few) geniculate neurons, while complex cells receive input from a larger region of geniculate neurons. On average, this region is invariant with eccentricity and, due to a changing magnification factor, complex fields increase in size with eccentricity much more than do simple cells. For complex cells, computations of this geniculate region transformed to cortical space provide a cortical extent equal to the spread of pyramidal cell basal dendrites.

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Neuronal basis of perceptual learning in striate cortex

Scientific Reports ◽

10.1038/srep24769 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 6

Author(s):

Zhen Ren ◽

Jiawei Zhou ◽

Zhimo Yao ◽

Zhengchun Wang ◽

Nini Yuan ◽

...

Keyword(s):

Spatial Frequency ◽

Perceptual Learning ◽

Contrast Sensitivity ◽

Striate Cortex ◽

Signal To Noise Ratio ◽

High Spatial Frequency ◽

Sensitivity Training ◽

Spatial Frequencies ◽

Cortex Area ◽

Adult Cats

Abstract It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect). However, the underlying neural mechanisms of this high spatial frequency training improvement remain to be elucidated. In the present study, we examined four properties of neurons in primary visual cortex (area 17) of adult cats that exhibited significantly improved acuity after contrast sensitivity training with a high spatial frequency grating and those of untrained control cats. We found no difference in neuronal contrast sensitivity or tuning width (Width) between the trained and untrained cats. However, the trained cats showed a displacement of the cells’ optimal spatial frequency (OSF) to higher spatial frequencies as well as a larger neuronal signal-to-noise ratio (SNR). Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally. These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR.

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Spatial properties of neurons in the monkey striate cortex

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1987.0044 ◽

1987 ◽

Vol 231 (1263) ◽

pp. 251-288 ◽

Cited By ~ 108

Keyword(s):

Receptive Field ◽

Contrast Sensitivity ◽

Visual Processing ◽

Striate Cortex ◽

Receptive Fields ◽

Spatial Filter ◽

Cortical Cells ◽

Simple Cells ◽

Gabor Function ◽

Difference Of Gaussians

Contrast sensitivity as a function of spatial frequency was determined for 138 neurons in the foveal region of primate striate cortex. The accuracy of three models in describing these functions was assessed by the method of least squares. Models based on difference-of-Gaussians (DOG) functions were shown to be superior to those based on the Gabor function or the second differential of a Gaussian. In the most general case of the DOG models, each subregion of a simple cell’s receptive field was constructed from a single DOG function. All the models are compatible with the classical observation that the receptive fields of simple cells are made up of spatially discrete ‘on’ and ‘off’ regions. Although the DOG-based models have more free parameters, they can account better for the variety of shapes of spatial contrast sensitivity functions observed in cortical cells and, unlike other models, they provide a detailed description of the organization of subregions of the receptive field that is consistent with the physiological constraints imposed by earlier stages in the visual pathway. Despite the fact that the DOG-based models have spatially discrete components, the resulting amplitude spectra in the frequency domain describe complex cells just as well as simple cells. The superiority of the DOG-based models as a primary spatial filter is discussed in relation to popular models of visual processing that use the Gabor function or the second differential of a Gaussian.

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Binocular visual processing in the owl’s telencephalon

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1979.0038 ◽

1979 ◽

Vol 204 (1157) ◽

pp. 435-454 ◽

Cited By ~ 73

Keyword(s):

Visual Processing ◽

Striate Cortex ◽

Functional Organization ◽

Receptive Fields ◽

Field Size ◽

Evolutionary Origins ◽

Structural Differences ◽

Output Neurons ◽

Global Stereopsis ◽

Orientation Movement

Single neurons recorded from the owl’s visual Wulst are surprisingly similar to those found in mammalian striate cortex. The receptive fields of Wulst neurons are elaborated, in an apparently hierarchical fashion,from those of their monocular, concentrically organized inputs to produce binocular interneurons with increasingly sophisticated requirements for stimulus orientation, movement and binocular disparity. Output neurons located in the superficial laminae of the Wulst are the most sophisticated of all, with absolute requirements for a combination of stimuli, which include binocular presentation at a particular horizontal binocular disparity, and with no response unless all of the stimulus conditions are satisfied simultaneously. Such neurons have the properties required for ‘global stereopsis,’ including a receptive field size many times larger than their optimal stimulus, which is more closely matched to the receptive fields of the simpler, disparity-selective interneurons. These marked similarities in functional organization between the avian and mammalian systems exist in spite of a number of structural differences which reflect their separate evolutionary origins. Discussion therefore includes the possibility that there may exist for nervous systems only a very small number of possible solutions, perhaps a unique one, to the problem of stereopsis.

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