Orientation selectivity of single cells in striate cortex of cat: The shape of orientation tuning curves

1978 ◽  
Vol 18 (8) ◽  
pp. 1067-1071 ◽  
Author(s):  
P. Heggelund ◽  
K. Albus
1985 ◽  
Vol 53 (5) ◽  
pp. 1158-1178 ◽  
Author(s):  
B. O. Braastad ◽  
P. Heggelund

The functional organization of the receptive field of neurons in striate cortex of kittens from 8 days to 3 mo of age was studied by extracellular recordings. A quantitative dual-stimulus technique was used, which allowed for analysis of both enhancement and suppression zones in the receptive field. Furthermore the development of orientation selectivity was studied quantitatively in the same cells. Already in the youngest kittens the receptive fields were spatially organized like adult fields, with a central zone and adjacent flanks that responded in opposite manner to the light stimulus. The relative suppression in the subzones was as strong as in adult cells. Both simple and complex cells were found from 8 days. The receptive fields were like magnified adult fields. The width of the dominant discharge-field zone and the distance between the positions giving maximum discharge and maximum suppression decreased with age in the same proportions. The decrease could be explained by a corresponding decrease of the receptive-field-center size of retinal ganglion cells. Forty percent of the cells were orientation selective before 2 wk, and the fraction increased to 94% at 4 wk. Cells whose responses could be attenuated to at least half of the maximal response by changes of slit orientation were termed orientation selective. The half-width of the orientation-tuning curves narrowed during the first 5 wk, and this change was most marked in simple cells. The ability of the cells to discriminate between orientations in statistical terms was weak in the youngest kittens due to a large response variability, and showed a more pronounced development than the half-width did. The orientation-tuning curves were fitted by an exponential function, which showed the shape to be adultlike in all age groups. Two kittens were dark reared until recording at 1 mo of age. The spatial receptive-field organization and the orientation selectivity in these kittens were similar to normal-reared kittens at 1 mo. The responsivity of the cells of the dark-reared kittens was lower, and the latency before firing was longer than in the normal-reared kittens of the same age, and these response properties were more similar to those in 1- to 2-wk-old normal kittens. Our results indicate that the spatial organization of the receptive field is innate in most cells and that visual experience is unnecessary for the organization to be maintained and for the receptive-field width to mature during the first month postnatally.(ABSTRACT TRUNCATED AT 400 WORDS)


1989 ◽  
Vol 2 (1) ◽  
pp. 41-55 ◽  
Author(s):  
A. B. Bonds

AbstractMechanisms supporting orientation selectivity of cat striate cortical cells were studied by stimulation with two superimposed sine-wave gratings of different orientations. One grating (base) generated a discharge of known amplitude which could be modified by the second grating (mask). Masks presented at nonoptimal orientations usually reduced the base-generated response, but the degree of reduction varied widely between cells. Cells with narrow orientation tuning tended to be more susceptible to mask presence than broadly tuned cells; similarly, simple cells generally showed more response reduction than did complex cells.The base and mask stimuli were drifted at different temporal frequencies which, in simple cells, permitted the identification of individual response components from each stimulus. This revealed that the reduction of the base response by the mask usually did not vary regularly with mask orientation, although response facilitation from the mask was orientation selective. In some sharply tuned simple cells, response reduction had clear local maxima near the limits of the cell's orientation-tuning function.Response reduction resulted from a nearly pure rightward shift of the response versus log contrast function. The lowest mask contrast yielding reduction was within 0.1–0.3 log unit of the lowest contrast effective for excitation.The temporal-frequency bandpass of the response-reduction mechanism resembled that of most cortical cells. The spatial-frequency bandpass was much broader than is typical for single cortical cells, spanning essentially the entire visual range of the cat.These findings are compatible with a model in which weak intrinsic orientation-selective excitation is enhanced in two stages: (1) control of threshold by nonorientation-selective inhibition that is continuously dependent on stimulus contrast; and (2) in the more narrowly tuned cells, orientation-selective inhibition that has local maxima serving to increase the slope of the orientation-tuning function.


1998 ◽  
Vol 15 (1) ◽  
pp. 177-196 ◽  
Author(s):  
J. MCLEAN ◽  
L.A. PALMER

We have utilized an associative conditioning paradigm to induce changes in the receptive field (RF) properties of neurons in the adult cat striate cortex. During conditioning, the presentation of particular visual stimuli were repeatedly paired with the iontophoretic application of either GABA or glutamate to control postsynaptic firing rates. Similar paradigms have been used in kitten visual cortex to alter RF properties (Fregnac et al., 1988, 1992; Greuel et al., 1988; Shulz & Fregnac, 1992). Roughly half of the cells that were subjected to conditioning with stimuli differing in orientation were found to have orientation tuning curves that were significantly altered. In general, the modification in orientation tuning was not accompanied by a shift in preferred orientation, but rather, responsiveness to stimuli at or near the positively reinforced orientation was increased relative to controls, and responsiveness to stimuli at or near the negatively reinforced orientation was decreased relative to controls. A similar proportion of cells that were subjected to conditioning with stimuli differing in spatial phase were found to have spatial-phase tuning curves that were significantly modified. Conditioning stimuli typically differed by 90 deg in spatial phase, but modifications in spatial-phase angle were generally 30–40 deg. An interesting phenomenon we encountered was that during conditioning, cells often developed a modulated response to counterphased grating stimuli presented at the null spatial phase. We present an example of a simple cell for which the shift in preferred spatial phase measured with counterphased grating stimuli was comparable to the shift in spatial phase computed from a one-dimensional Gabor fit of the space-time RF profile. One of ten cells tested had a significant change in direction selectivity following associative conditioning. The specific and predictable modifications of RF properties induced by our associative conditioning procedure demonstrate the ability of mature visual cortical neurons to alter their integrative properties. Our results lend further support to models of synaptic plasticity where temporal correlations between presynaptic and postsynaptic activity levels control the efficiency of transmission at existing synapses, and to the idea that the mature visual cortex is, in some sense, dynamically organized.


1976 ◽  
Vol 39 (6) ◽  
pp. 1320-1333 ◽  
Author(s):  
P. H. Schiller ◽  
B. L. Finlay ◽  
S. F. Volman

1. Quantitative analyses of orientation specificity and ocular dominance were carried out in striate cortex of the rhesus monkey. 2. Sharpness of orientation selectivity was greater for simple (S type) than for complex (CX type) cells. CX-type cells became more broadly tuned in the deeper cortical layers: S-type cells were equally well tuned throughout the cortex. 3. Sharpness of orientation selectivity for S-type cells was similar at all retinal eccentricities studied (0 degrees - 20 degrees from the fovea):in CX-type cells orientation selectivity decreased slightly with increasing eccentricity. 4. The orientation tuning of binocular cells was similar when mapped separately through each eye. 5. Orientation selectivity and direction selectivity are independent of each other, suggesting that separate neural mechanisms give rise to them. 6. More CX-type cells can be binocularly activated than S-type cells (88% versus 49%). The ocular dominance of S-type cells is similar in all cortical layers: for CX-type cells there is an increase in the number of cells in ocular-dominance category 4 in layers 5 and 6.


2003 ◽  
Vol 90 (1) ◽  
pp. 204-217 ◽  
Author(s):  
Baowang Li ◽  
Matthew R. Peterson ◽  
Ralph D. Freeman

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.


1997 ◽  
Vol 14 (1) ◽  
pp. 141-158 ◽  
Author(s):  
John M. Crook ◽  
Zoltan F. Kisvárday ◽  
Ulf T. Eysel

AbstractMicroiontophoresis of γ-aminobutyric acid (GABA) was used to reversibly inactivate small sites of defined orientation/direction specificity in layers II-IV of cat area 17 while single cells were recorded in the same area at a horizontal distance of ~350–700 jam. We compared the effect of inactivating iso-orientation sites (where orientation preference was within 22.5 deg) and cross-orientation sites (where it differed by 45–90 deg) on orientation tuning and directionality. The influence of iso-orientation inactivation was tested in 33 cells, seven of which were subjected to alternate inactivation of two iso-orientation sites with opposite direction preference. Of the resulting 40 inactivations, only two (5%) caused significant changes in orientation tuning, whereas 26 (65%) elicited effects on directionality: namely, an increase or a decrease in response to a cell's preferred direction when its direction preference was the same as that at an inactivation site, and an increase in response to a cell's nonpreferred direction when its direction preference was opposite that at an inactivation site. It is argued that the decreases in response to the preferred direction reflected a reduction in the strength of intracortical iso-orientation excitatory connections, while the increases in response were due to the loss of iso-orientation inhibition. Of 35 cells subjected to cross-orientation inactivation, only six (17%) showed an effect on directionality, whereas 21 (60%) showed significant broadening of orientation tuning, with an increase in mean tuning width at half-height of 126%. The effects on orientation tuning were due to increases in response to nonoptimal orientations. Changes in directionality also resulted from increased responses (to preferred or nonpreferred directions) and were always accompanied by broadening of tuning. Thus, the effects of cross-orientation inactivation were presumably due to the loss of a cross-orientation inhibitory input that contributes mainly to orientation tuning by suppressing responses to nonoptimal orientations. Differential effects of iso-orientation and cross-orientation inactivation could be elicited in the same cell or in different cells from the same inactivation site. The results suggest the involvement of three different intracortical processes in the generation of orientation tuning and direction selectivity in area 17: (1) suppression of responses to nonoptimal orientations and directions as a result of cross-orientation inhibition and iso-orientation inhibition between cells with opposite direction preferences; (2) amplification of responses to optimal stimuli via iso-orientation excitatory connections; and (3) regulation of cortical amplification via iso-orientation inhibition.


1990 ◽  
Vol 2 (2) ◽  
pp. 152-161 ◽  
Author(s):  
M. Devos ◽  
G. A. Orban

We trained a multilayer perceptron with backpropagation to perform stimulus orientation discrimination at multiple references using biologically plausible values as input and output. Hidden units are necessary for good performance only when the network must operate at multiple reference orientations. The orientation tuning curves of the hidden units change with reference. Our results suggest that at least for simple parameter discriminations such as orientation discrimination, one of the main functions of further processing in the visual system beyond striate cortex is to combine signals representing stimulus and reference.


1995 ◽  
Vol 12 (5) ◽  
pp. 805-817 ◽  
Author(s):  
N.v. Swindale

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.


2003 ◽  
Vol 90 (2) ◽  
pp. 822-831 ◽  
Author(s):  
James R. Müller ◽  
Andrew B. Metha ◽  
John Krauskopf ◽  
Peter Lennie

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.


2003 ◽  
Vol 89 (4) ◽  
pp. 2086-2100 ◽  
Author(s):  
Andrew F. Teich ◽  
Ning Qian

Learning and adaptation in the domain of orientation processing are among the most studied topics in the literature. However, little effort has been devoted to explaining the diverse array of experimental findings via a physiologically based model. We have started to address this issue in the framework of the recurrent model of V1 orientation selectivity and found that reported changes in V1 orientation tuning curves after learning and adaptation can both be explained with the model. Specifically, the sharpening of orientation tuning curves near the trained orientation after learning can be accounted for by slightly reducing net excitatory connections to cells around the trained orientation, while the broadening and peak shift of the tuning curves after adaptation can be reproduced by appropriately scaling down both excitation and inhibition around the adapted orientation. In addition, we investigated the perceptual consequences of the tuning curve changes induced by learning and adaptation using signal detection theory. We found that in the case of learning, the physiological changes can account for the psychophysical data well. In the case of adaptation, however, there is a clear discrepancy between the psychophysical data from alert human subjects and the physiological data from anesthetized animals. Instead, human adaptation studies can be better accounted for by the learning data from behaving animals. Our work suggests that adaptation in behaving subjects may be viewed as a short-term form of learning.


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