Discrimination of orientation and position disparities by binocularly activated neurons in cat straite cortex

1977 ◽  
Vol 40 (2) ◽  
pp. 260-283 ◽  
Author(s):  
J. I. Nelson ◽  
H. Kato ◽  
P. O. Bishop
Keyword(s):  
Ocular Dominance ◽  
Stimulus Orientation ◽  
Orientation Tuning ◽  
Simple Cells ◽  
Tuning Curves ◽  
Complex Cells ◽  
Eye Rotation ◽  
Striate Neurons ◽  
The Mean ◽  
Orientation Disparity

1. We have examined and compared the ability of binocularly activated striate neurons to make both position disparity and orientation disparity discrimination in the anesthetized (N2O/O2) and paralyzed cat preparation. 2. Accurate knowledge of eye position is essential for disparity studies. Using a retinal projection technique able to detect eye drifts of less than 3' arc per retinal landmark and less than 18' arc cyclorotation disparity, we determined eye drift during the course of 2- to 4-day experiments. After the initial eye rotation due to the anesthesia and the onset of paralysis (see below), rotational drift thereafter was mainly excyclorotatory and, from all causes, rarely totaled more than 4 degrees disparity. All our data have been corrected for this residual cyclorotatory drift. 3. Optimal stimulus orientation disparities were determined from quantitative monocular orientation tuning curves for 74 binocularly activated striate cells (37 simple, 3 hypercomplex I, 31 complex, 3 hypercomplex II) from nine cats. Without exception, the mean optimal stimulus orientation disparity in each of our animals showed a departure from zero disparity equivalent to an incyclorotation of the eyes (mean, 9.2 degrees; range, 2.7 degrees-15.9 degrees). 4. We attribute this mean optimal stimulus orientation disparity shift to ocular cyclorotation as a result of the initial anesthesia and paralysis. Assuming equal intortion, incyclorotation for each eye averages 4.6 degrees. On the assumption that the mean optimal stimulus orientation disparity is zero in normal life, we pooled results from the nine animals about their individual means. For the 74 cells the resulting distribution of the optimal stimulus orientation disparities had a range of about +/-15 degrees (simple cells: SD 4.9 degrees; complex cells: SD 7.4 degrees). 5. We examined the relationship of the sharpness of the orientation tuning curves to ocular dominance, to absolute orientation preference, and to other unit properties. The striking observation was the high correlation between the sharpness of orientation tuning curves for the two eyes of a binocular neuron. For simple cells the mean difference for the half-widths of half-height was only 2.54 degrees, with sharpness showing a high correlation between the two eyes (r=0.915) over half-width at half-heights ranging from 8.5 degrees to 41.8 degrees. Complex cells showed a similar, albeit weaker, correlation. 6. Having shown that, assessed monocularly binocular units show different orientation tunings in the two eyes, we undertook binocular experiments to ascertain if these differences were the optimal disparities of sharply tuned stimulus orientation disparity channels. Using a matrix stimulation paradigm to minimize the effects of spontaneous changes in responsiveness, we have simultaneously extracted bionocular stimulus orientation disparity and position disparity tuning curves from single striate neurons...

Oblique Effect: A Neural Basis in the Visual Cortex

2003 ◽  
Vol 90 (1) ◽  
pp. 204-217 ◽  
Author(s):  
Baowang Li ◽  
Matthew R. Peterson ◽  
Ralph D. Freeman
Keyword(s):  
Striate Cortex ◽  
Oblique Effect ◽  
Orientation Tuning ◽  
Neural Basis ◽  
Linear Filters ◽  
Simple Cells ◽  
Tuning Curves ◽  
Complex Cells ◽  
Behavioral Studies ◽  
Spatial Frequencies

The details of oriented visual stimuli are better resolved when they are horizontal or vertical rather than oblique. This “oblique effect” has been confirmed in numerous behavioral studies in humans and to some extent in animals. However, investigations of its neural basis have produced mixed and inconclusive results, presumably due in part to limited sample sizes. We have used a database to analyze a population of 4,418 cells in the cat's striate cortex to determine possible differences as a function of orientation. We find that both the numbers of cells and the widths of orientation tuning vary as a function of preferred orientation. Specifically, more cells prefer horizontal and vertical orientations compared with oblique angles. The largest population of cells is activated by orientations close to horizontal. In addition, orientation tuning widths are most narrow for cells preferring horizontal orientations. These findings are most prominent for simple cells tuned to high spatial frequencies. Complex cells and simple cells tuned to low spatial frequencies do not exhibit these anisotropies. For a subset of simple cells from our population ( n = 104), we examined the relative contributions of linear and nonlinear mechanisms in shaping orientation tuning curves. We find that linear contributions alone do not account for the narrower tuning widths at horizontal orientations. By modeling simple cells as linear filters followed by static expansive nonlinearities, our analysis indicates that horizontally tuned cells have a greater nonlinear component than those tuned to other orientations. This suggests that intracortical mechanisms play a major role in shaping the oblique effect.

Responses of neurons in cat striate cortex to vernier offsets in reverse contrast stimuli

1995 ◽  
Vol 12 (5) ◽  
pp. 805-817 ◽  
Author(s):  
N.v. Swindale
Keyword(s):  
Striate Cortex ◽  
Tuning Curve ◽  
High Sensitivity ◽  
Orientation Tuning ◽  
Vernier Acuity ◽  
Simple Cells ◽  
Tuning Curves ◽  
Complex Cells ◽  
Simple And Complex Cells ◽  
Opposite Contrast

AbstractThis paper examines how the responses of cells in area 17 of the cat vary as a function of the vernier offset between a bright and a dark bar. The study was prompted by the finding that human vernier acuity is reduced for bars or edges of opposite contrast sign (Mather & Morgan, 1986; O'Shea & Mitchell, 1990). Both simple and complex cells showed V-shaped tuning curves for reverse contrast stimuli: i.e. response was minimum at alignment, and increased with increasing vernier offset. For vernier bars with the same contrast sign, γ-shaped tuning curves were found, as reported earlier (Swindale & Cynader, 1986). Sensitivity to offset was inversely correlated in the two paradigms. However, complex cells with high sensitivity to offsets in a normal vernier stimulus were significantly less sensitive to offsets in reverse contrast stimuli. A cell's response to a vernier stimulus in which both bars are bright can be predicted by the shape of its orientation tuning curve, if the vernier stimulus is approximated by a single bar with an orientation equal to that of a line joining the midpoints of the two component bars (Swindale & Cynader, 1986). This approximation did not hold for the reverse contrast condition: orientation tuning curves for compound barswere broad and shallow, rather than bimodal, with peaks up to 40 deg from the preferred orientation. Results from simple cells were compared with predictions made by a linear model of the receptive field. The model predicted the V-shaped tuning curves found for reverse contrast stimuli. It also predicted that absolute values of tuning slopes for vernier offsets in reverse contrast stimuli might sometimes be higher than with normal stimuli. This was observed in some simple cells. The model was unable to explain the shape of orientation tuning curves for compound bars, nor could it explain the breakdown of the equivalent orientation approximation.

scholarly journals V1 orientation plasticity is explained by broadly tuned feedforward inputs and intracortical sharpening

2010 ◽  
Vol 27 (1-2) ◽  
pp. 57-73 ◽  
Author(s):  
ANDREW F. TEICH ◽  
NING QIAN
Keyword(s):  
Tuning Curve ◽  
Orientation Discrimination ◽  
Orientation Tuning ◽  
Plastic Properties ◽  
Simple Cells ◽  
Tuning Curves ◽  
Complex Cells ◽  
Learning And Adaptation ◽  
Mere Presence ◽  
Simple And Complex Cells

AbstractOrientation adaptation and perceptual learning change orientation tuning curves of V1 cells. Adaptation shifts tuning curve peaks away from the adapted orientation, reduces tuning curve slopes near the adapted orientation, and increases the responses on the far flank of tuning curves. Learning an orientation discrimination task increases tuning curve slopes near the trained orientation. These changes have been explained previously in a recurrent model (RM) of orientation selectivity. However, the RM generates only complex cells when they are well tuned, so that there is currently no model of orientation plasticity for simple cells. In addition, some feedforward models, such as the modified feedforward model (MFM), also contain recurrent cortical excitation, and it is unknown whether they can explain plasticity. Here, we compare plasticity in the MFM, which simulates simple cells, and a recent modification of the RM (MRM), which displays a continuum of simple-to-complex characteristics. Both pre- and postsynaptic-based modifications of the recurrent and feedforward connections in the models are investigated. The MRM can account for all the learning- and adaptation-induced plasticity, for both simple and complex cells, while the MFM cannot. The key features from the MRM required for explaining plasticity are broadly tuned feedforward inputs and sharpening by a Mexican hat intracortical interaction profile. The mere presence of recurrent cortical interactions in feedforward models like the MFM is insufficient; such models have more rigid tuning curves. We predict that the plastic properties must be absent for cells whose orientation tuning arises from a feedforward mechanism.

Processing of form and motion in area 21a of cat visual cortex

1993 ◽  
Vol 10 (1) ◽  
pp. 93-115 ◽  
Author(s):  
B. Dreher ◽  
A. Michalski ◽  
R. H. T. Ho ◽  
C. W. F. Lee ◽  
W. Burke
Keyword(s):  
Spatial Organization ◽  
Receptive Fields ◽  
Direction Selectivity ◽  
Orientation Tuning ◽  
Area 17 ◽  
Horizontal Strip ◽  
Tuning Curves ◽  
Mean Width ◽  
Area 21A ◽  
The Mean

AbstractExtracellular recordings from single neurons have been made from presumed area 21a of the cerebral cortex of the cat, anesthetized with N2O/O2/sodium pentobarbitone mixture. Area 21a contains mainly a representation of a central horizontal strip of contralateral visual field about 5 deg above and below the horizontal meridian.Excitatory discharge fields of area 21a neurons were substantially (or slightly but significantly) larger than those of neurons at corresponding eccentricities in areas 17, 19, or 18, respectively. About 95% of area 21a neurons could be activated through either eye and the input from the ipsilateral eye was commonly dominant. Over 90% and less than 10% of neurons had, respectively, C-type and S-type receptive-field organization. Virtually all neurons were orientation-selective and the mean width at half-height of the orientation tuning curves at 52.9 deg was not significantly different from that of neurons in areas 17 and 18. About 30% of area 21a neurons had preferred orientations within 15 deg of the vertical.The mean direction-selectivity index (32.8%) of area 21a neurons was substantially lower than the indices for neurons in areas 17 or 18. Only a few neurons exhibited moderately strong end-zone inhibition. Area 21a neurons responded poorly to fast-moving stimuli and the mean preferred velocity at about 12.5 deg/s was not significantly different from that for area 17 neurons.Selective pressure block of Y fibers in contralateral optic nerve resulted in a small but significant reduction in the preferred velocities of neurons activated via the Y-blocked eye. By contrast, removal of the Y input did not produce significant changes in the spatial organization of receptive fields (S or C type), the size of the discharge fields, the width of orientation tuning curves, or direction-selectivity indices.Our results are consistent with the idea that area 21a receives its principal excitatory input from area 17 and is involved mainly in form rather than motion analysis.

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

1976 ◽  
Vol 39 (3) ◽  
pp. 512-533 ◽  
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.

Space-time spectra of complex cell filters in the macaque monkey: A comparison of results obtained with pseudowhite noise and grating stimuli

1994 ◽  
Vol 11 (4) ◽  
pp. 805-821 ◽  
Author(s):  
James P. Gaska ◽  
Lowell D. Jacobson ◽  
Hai-Wen Chen ◽  
Daniel A. Pollen
Keyword(s):  
Spatial Frequency ◽  
Macaque Monkey ◽  
Spike Rate ◽  
Second Order ◽  
Orientation Tuning ◽  
Complex Cell ◽  
Interaction Function ◽  
Tuning Curves ◽  
Complex Cells ◽  
Order Kernel

AbstractWhite noise stimuli were used to estimate second-order kernels for complex cells in cortical area VI of the macaque monkey, and drifting grating stimuli were presented to the same sample of neurons to obtain orientation and spatial-frequency tuning curves. Using these data, we quantified how well second-order kernels predict the normalized tuning of the average response of complex cells to drifting gratings.The estimated second-order kernel of each complex cell was transformed into an interaction function defined over all spatial and temporal lags without regard to absolute position or delay. The Fourier transform of each interaction function was then computed to obtain an interaction spectrum. For a cell that is well modeled by a second-order system, the cell’s interaction spectrum is proportional to the tuning of its average spike rate to drifting gratings. This result was used to obtain spatial-frequency and orientation tuning predictions for each cell based on its second-order kernel. From the spatial-frequency and orientation tuning curves, we computed peaks and bandwidths, and an index for directional selectivity.We found that the predictions derived from second-order kernels provide an accurate description of the change in the average spike rate of complex cells to single drifting sine–wave gratings. These findings are consistent with a model for complex cells that has a quadratic spectral energy operator at its core but are inconsistent with a spectral amplitude model.

Discrimination of orientation and position disparities by binocularly activated neurons in cat striate cortex

1977 ◽  
Vol 40 (6) ◽  
pp. 1443-1443 ◽  
Author(s):  
J. I. Nelson ◽  
H. Kato ◽  
P. O. Bishop
Keyword(s):  
Striate Cortex ◽  
Tuning Curve ◽  
Stimulus Orientation ◽  
Complex Cell ◽  
Tuning Curves ◽  
The Right ◽  
Cat Striate Cortex ◽  
Orientation Disparity

Page 275: J. I. Nelson, H. Kato, and P. O. Bishop, “Discrimination of orientation and position disparities by binocularly activated neurons in cat striate cortex.” The legend to the figure at the bottom of page 325 should read: fig 9. Matrix stimulation experiment for a complex cell. The 17 position disparity tuning curves, separated from each other by orientation disparity increments of 7°, span an orientation range of 112°. Each position disparity tuning curve has six increments of 24' arc disparity spanning 2.4°. The stimulus orientation disparities were obtained by keeping the stimulus orientation for the left eye fixed at 112° and varying the orientation for the right eye. Monocular controls (open circles, filled triangles, and short continuous lines) same as for Fig. 8.

scholarly journals Comparison Among Some Models of Orientation Selectivity

2006 ◽  
Vol 96 (1) ◽  
pp. 404-419 ◽  
Author(s):  
Andrew F. Teich ◽  
Ning Qian
Keyword(s):  
Peak Shift ◽  
Orientation Tuning ◽  
Complex Spectrum ◽  
Complex Cell ◽  
Phase Information ◽  
Simple Complex ◽  
Simple Cells ◽  
Complex Cells ◽  
Spatial Phase ◽  
Opposite Contrast

Several models exist for explaining primary visual cortex (V1) orientation tuning. The modified feedforward model (MFM) and the recurrent model (RM) are major examples. We have implemented these two models, at the same level of detail, alongside a few newer variations, and thoroughly compared their receptive-field structures. We found that antiphase inhibition in the MFM enhances both spatial phase information and orientation tuning, producing well-tuned simple cells. This remains true for a newer version of the MFM that incorporates untuned complex-cell inhibition. In contrast, when the recurrent connections in the RM are strong enough to produce typical V1 orientation tuning, they also eliminate spatial phase information, making the cells complex. Introducing phase specificity into the connections of the RM (as done in an original version of the RM) can make the cells phase sensitive, but the cells show an incorrect 90° peak shift of orientation tuning under opposite contrast signs. An inhibition-dominant version of the RM can generate well-tuned cells across the simple–complex spectrum, but it predicts that the net effect of cortical interactions is to suppress feedforward excitation across all orientations in simple cells. Finally, adding antiphase inhibition used in the MFM into the RM produces a most general model. We call this new model the modified recurrent model (MRM) and show that this model can also produce well-tuned cells throughout the simple–complex spectrum. Unlike the inhibition-dominant RM, the MRM is consistent with data from cat V1, suggesting that the net effect of cortical interactions is to boost simple cell responses at the preferred orientation. These results suggest that the MFM is well suited for explaining orientation tuning in simple cells, whereas the standard RM is for complex cells. The assignment of the RM to complex cells also avoids conflicts between the RM and the experiments of cortical inactivation (done on simple cells) and the spatial-frequency dependency of orientation tuning (found in simple cells). Because orientation-tuned V1 cells show a continuum of simple- to complex-cell behavior, the MRM provides the best description of V1 data.

scholarly journals Local Signals From Beyond the Receptive Fields of Striate Cortical Neurons

2003 ◽  
Vol 90 (2) ◽  
pp. 822-831 ◽  
Author(s):  
James R. Müller ◽  
Andrew B. Metha ◽  
John Krauskopf ◽  
Peter Lennie
Keyword(s):  
Receptive Field ◽  
Cortical Neurons ◽  
Striate Cortex ◽  
Image Representation ◽  
Receptive Fields ◽  
Preferred Orientation ◽  
Orientation Tuning ◽  
Stimulus Space ◽  
Tuning Curves ◽  
Complex Cells

We examined in anesthetized macaque how the responses of a striate cortical neuron to patterns inside the receptive field were altered by surrounding patterns outside it. The changes in a neuron's response brought about by a surround are immediate and transient: they arise with the same latency as the response to a stimulus within the receptive field (this argues for a source locally in striate cortex) and become less effective as soon as 27 ms later. Surround signals appeared to exert their influence through divisive interaction (normalization) with those arising in the receptive field. Surrounding patterns presented at orientations slightly oblique to the preferred orientation consistently deformed orientation tuning curves of complex (but not simple) cells, repelling the preferred orientation but without decreasing the discriminability of the preferred grating and ones at slightly oblique orientations. By reducing responsivity and changing the tuning of complex cells locally in stimulus space, surrounding patterns reduce the correlations among responses of neurons to a particular stimulus, thus reducing the redundancy of image representation.

Functional organization of neurons in cat striate cortex: variations in ocular dominance and receptive-field type with cortical laminae and location in visual field

1982 ◽  
Vol 48 (6) ◽  
pp. 1362-1377 ◽  
Author(s):  
N. Berman ◽  
B. R. Payne ◽  
D. R. Labar ◽  
E. H. Murphy
Keyword(s):  
Visual Field ◽  
Receptive Field ◽  
Functional Organization ◽  
Visual Stimulation ◽  
Ocular Dominance ◽  
Cortical Layers ◽  
Vertical Meridian ◽  
Simple Cells ◽  
Complex Cells ◽  
Field Type

1. Binocularity and receptive-field type of cortical neurons were assessed relative to the cortical layer in which the neurons were recorded and to receptive-field position in the visual field. 2. Receptive fields were observed up to 2 degrees into the ipsilateral half of the visual field. In the region up to 2 degrees on either side of the vertical meridian, the relative contribution of the ipsilateral eye was reduced. This progression in ocular dominance from ipsilateral to contralateral visual field agrees well with the distribution of X-cells about the nasotemporal division. 3. The region of maximum binocularity in each hemifield was found to be a 12 degree wide vertical strip extending from the vertical meridian to 12 degrees contralateral. In the representation of the central 12 degree strip, most units in all cortical layers were binocular. 4. Low levels of binocularity were observed at a considerable distance before the monocular portion of the visual field was reached. 5. The decrease in binocularity for simple cells occurred closer to the vertical meridian than for complex cells. 6. The proportions of cells classified as simple or complex did not change with position in the visual field. 7. At all locations in the visual field, complex cells showed a higher percentage of binocularity than simple cells. 8. The proportions of two types of simple cells, I and II, and complex cells were variable between cortical layers. Layer IV contained predominantly simple II cells, whereas layer V contained predominantly complex cells. 9. The results are discussed in terms of visual perception and the dynamic pattern of visual stimulation around a moving animal, the optic flow field.

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