Quantitative studies of single-cell properties in monkey striate cortex. I. Spatiotemporal organization of receptive fields.
Schiller PH; Finlay BL; Volman SF
Journal of Neurophysiology, 1976 Nov, 39:6, 1288-319.
Abstract
1. The properties of single cells in striate cortex of the rhesus monkey, representing the visual field 2 degrees -5 degrees from the fovea, were examined quantitatively with stationary and moving stimuli. Three distinct classes of cells were identified: S type, CX type, and T type.
2. S-type cells were defined as those oriented cells which to the optimal direction of movement in their receptive fields exhibited one or more spatially separate subfields within each of which a response was obtained to either a light or dark edge, but not to both. Several different types of S-cells were distinguished: a) S1-type cells for which moving edges revealed a single excitatory area within which a response was elicited by either a light or a dark edge but not by both. Most of these cells were unidirectional. b) S2-type cells for which moving edges revealed two spatially separate response areas, one of which was excited by a light edge and the other by a dark edge. Both regions responded to the same direction of movement. c) S3-type cells which had two response areas, one of which was excited by a stimulus moving in one direction (at right angles to the axis of orientation) and the other, of opposite contrast, which responded in the opposite direction, d) S4-type cells which to one direction of movement showed two spatially separate regions sensitive to a light and dark edge and which in the other direction of movement had only one responsive area (either light or dark). e) Cells which had multiple spatially separate subfields (S5-7 types).
3. CX-type cells were defined as those oriented cells which in their receptive fields exhibited no spatial separation for light- and dark-edge responses; they discharged to both edges in the same direction of movement and in the same spatial area. Flashing stimuli elicited both on and off responses throughout the receptive field. CX-type cells were predominantly of two types: those which were selective for direction of stimulus movement and those which were not.
4. A third class of cells (T-type) were those which were excited by only one sign of contrast change and responded in a sustained fashion even when there was no contour within the receptive field. These cells were poorly or not at all oriented; some of them were selective to wavelength.
5. Quantitative comparisons showed the following differences between S-type and CX-type cells: a) S-type cells had smaller receptive fields than CX-type cells but the populations over-lapped considerably. Receptive-field size was smallest in layer 4c. In all other layers S-type cells had the same size fields. CX-type cells, by contrast, tended to have larger fields in layer 5-6 than 2-3. b) The spatial separation between light and dark response areas was the best criterion for distinguishing S-type and CX-type cells. The distribution of this measure disclosed two populations of cells with relatively limited overlap. c) In layers 2 and 3, both S-type and CX-type cells had low spontaneous activity.
| Unique Identifier | 77053095 |
| Publication Type | JOURNAL ARTICLE |
| ISSN | 0022-3077 |
| Country of Publication | UNITED STATES |
Quantitative studies of single-cell properties in monkey striate cortex. II. Orientation specificity and ocular dominance.
Schiller PH; Finlay BL; Volman SF
Journal of Neurophysiology, 1976 Nov, 39:6, 1320-33.
Abstract
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.
| Unique Identifier | 77053096 |
| Publication Type | JOURNAL ARTICLE |
| ISSN | 0022-3077 |
| Country of Publication | UNITED STATES |
Quantitative studies of single-cell properties in monkey striate cortex. III. Spatial frequency.
Schiller PH; Finlay BL; Volman SF
Journal of Neurophysiology, 1976 Nov, 39:6, 1334-51
Abstract
1. The response properties of single cells in monkey striate cortex were examined using moving bars, square-wave gratings, and sine-wave gratings.
2. The moving of cells studied were not selective for bar width or for the spatial frequency of square-wave gratings.
3. Most cells responded selectively to the spatial frequency of the sine-wave gratings.
4. The spatial frequency of the sine-wave grating eliciting the optimal response could not be predicted from the organization of the receptive field of each cell as determined by stationary or moving stimuli.
5. The sharpness of spatial-frequency selectivity is only slightly more pronounced in S-type cells than in CX-type cells.
6. S-type and CX-type cells differ significantly in the temporal modulation of their discharges to gratings. S-type cells discharge in sharp bursts to each cycle which traverses the receptive field. CX-type cells discharge in a rather continuous fashion. This measure can be used reliably to classify cells as S or CS type.
| Unique Identifier | 77053097 |
| Publication Type | JOURNAL ARTICLE |
| ISSN | 0022-3077 |
| Country of Publication | UNITED STATES |
Quantitative studies of single-cell properties in monkey striate cortex. IV. Corticotectal
cells.
Finlay BL; Schiller PH; Volman SF
Journal of Neurophysiology, 1976 Nov, 39:6, 1352-61.
Abstract
1. The receptive-field properties of corticotectal cells in the monkey's striate cortex were studied using stationary and moving stimuli. These cells were identified by antidromic activation from the superior colliculus.
2. Corticotectal cells form a relatively homogeneous group. They are found primarily in layers 5 and 6. These cells can usually be classified as CX-type cells but show broader orientation tuning, larger receptive fields, higher spontaneous activity, and greater binocular activation than CX-type cells do in general. A third of the corticotectal cells were direction selective.
3. These results suggest that the cortical input to the superior colliculus is not directly responsible for the receptive-field properties of collicular cells. We propose that this input has a gating function in contributing to the control of the downflow of excitation from the superficial to the deep layers of the colliculus.
| Unique Identifier | 77053098 |
| Publication Type | JOURNAL ARTICLE |
| ISSN | 0022-3077 |
| Country of Publication | UNITED STATES |
Quantitative studies of single-cell properties in monkey striate cortex. V. Multivariate Statistical analyses and models.
Schiller PH; Finlay BL; Volman SF
Journal of Neurophysiology, 1976 Nov, 39:6, 1362-74.
Abstract
1. Several statistical analyses were performed on 205 S-type and CX-type cells which had been completely analyzed on 12 response variables: orientation tuning, end stopping, spontaneous activity, response variability, direction selectivity, contrast selectivity for flashed or moving stimuli, selectivity for interaction of contrast and direction of stimulus movement, spatial-frequency selectivity, spatial separation of subfields responding to light increment of light decrement, sustained/transient response to flash, receptive-field size, and ocular dominance.
2. Correlation of these variables showed that within any cell group, these response variables vary independently.
3. A multivariate discriminant analysis showed that orientation specificity, receptive-field size, interaction of direction and contrast specificity ocular dominance, and spontaneous activity, taken together can adequately assign cells into the S-type or CX-type subgroups.
4. Various models of visual cortex are examined in view of the findings reported here and in the previous papers of this series, which suggest that a) orientation and direction selectivities are produced by separate neural mechanisms, b) there may be hierarchy among simple (S type) cells, and c) complex (CX-type) cells appear to receive a prominent S-type cell input.
| Unique Identifier | 77053099 |
| Publication Type | JOURNAL ARTICLE |
| ISSN | 0022-3077 |
| Country of Publication | UNITED STATES |
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