Areal influences on complex cells in cat striate cortex: stimulus-specificity of width and length summation

1990 ◽  
Vol 80 (1) ◽  
Author(s):  
P. Hammond ◽  
I.M.E. Munden
1976 ◽  
Vol 39 (3) ◽  
pp. 512-533 ◽  
Author(s):  
J. R. Wilson ◽  
S. M. Sherman

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.


1998 ◽  
Vol 18 (19) ◽  
pp. 8086-8094 ◽  
Author(s):  
Judith A. Hirsch ◽  
Christine A. Gallagher ◽  
José-Manuel Alonso ◽  
Luis M. Martinez

1993 ◽  
Vol 69 (6) ◽  
pp. 2209-2221 ◽  
Author(s):  
S. Marlin ◽  
R. Douglas ◽  
M. Cynader

1. Responses of complex cells in cat striate cortex were studied with flashed light slit stimuli. The responses to slits flashed in different positions in the receptive field were assessed quantitatively before and after periods of prolonged stimulation of one small region of the receptive field. This type of prolonged stimulation resulted in reduced responsivity over a limited zone within the complex cell receptive field. 2. The adaptation-induced responsivity decrement was generally observed in both the ON and OFF response profiles but could also be restricted to one or the other. In general, the magnitude of the response decrements was greatest in the ON response profiles. The adaptation-induced response decrement did not necessarily spread throughout the receptive field but was restricted to a small region surrounding the adapted receptive field position (RFP). Adaptation spread equally widely across the ON and OFF response profiles despite the smaller adaptation effects in the OFF profile. 3. The adaptation effects from repeated stimulation at a single RFP did not spread symmetrically across the receptive field, and a given cell's preferred direction of motion indicated the direction of the asymmetric spread of the adaptation. RFPs that would be stimulated by a light slit originating at the point of adaptation and moving in the preferred direction (preferred side) showed greater adaptation-induced response decrements than did RFPs that would be stimulated by a light slit moving in the opposite direction from the point of adaptation (nonpreferred side). There was significant enhancement of responses at some RFPs on the non-preferred side of the point of adaptation. This asymmetric spread of adaptation could be caused by adaptation of inhibitory connections that contribute to complex cell direction selectivity. 4. The asymmetry of adaptation was significantly different for the ON and OFF response profiles. The asymmetric spread of adaptation for the ON response profile was similar to that observed previously in simple cells with greater decrements in the preferred direction side of the point of adaptation. However, the OFF response profiles showed less directional asymmetry in the spread of adaptation and showed greater decrements at RFPs in the nonpreferred direction side of the point of adaptation. 5. The similarity between the spread of adaptation in simple and complex cells suggests that the adaptation in these cells is occurring through a common mechanism. The directional asymmetry of the spread of adaptation is likely due to a local postsynaptic mechanism of adaptation rather than presynaptic transmitter depletion.


1984 ◽  
Vol 52 (3) ◽  
pp. 570-594 ◽  
Author(s):  
B. R. Payne ◽  
H. E. Pearson ◽  
N. Berman

The short-term (3-51 days) and long-term (31-42 wk) effects of corpus callosum transection on the receptive-field properties of neurons were assessed at the single-cell, architectural, and topographical levels of organization in the cat striate cortex. Corpus callosum transection decreased the proportion of neurons that could be activated from both eyes. In short-term animals, the reduction in binocularity was restricted to the representation of a vertical strip of visual space extending from the vertical meridian to at least 12 degrees lateral. In the long-term animals, the reduction in binocularity was restricted to the representation of visual space 4 degrees lateral to the vertical meridian. Therefore, the reduction in the representation of 4-12 degrees was only temporary. In both groups, the reduction in binocularity was less in the representation of area centralis than at other retinal locations in the same vertical strip. The region of area 17 affected permanently by the transection receives fibers from the contralateral hemisphere in normal animals. The region affected temporarily by the transection contains callosal cells but does not contain callosal terminals. Binocularity was assessed separately for simple I, simple II, and complex receptive-field types. The reduction in binocularity in the 12 degrees strip in short-term animals and in the 4 degrees strip in long-term animals was accounted for mainly by a reduction in binocularity of simple I and complex cells. As in normal animals, complex cells in callosum-transected cats were always more binocular than the other cell types. An analysis of the effects of corpus callosum transection on different cortical layers showed that a greater proportion of cells in the supragranular layers II and III showed a reduction in binocularity than in the infragranular layers V and VI. The proportion of binocular neurons in layer IV was not significantly different from normal. The major decreases in binocularity occurred in layers II, III, and VI for simple I and simple II cells and in layers II, III, and V for complex cells. The binocularity of simple II cells in layer IV and complex cells in layer VI was not affected. The effects of the transection on the columnar organization of the cortex were assessed by making electrode tracks that passed in the radial or laminar dimensions of the cortex. Reconstructions of the radial tracks showed that cells within one radial column tended to be dominated by the same eye. In adjacent columns, cells tended to be dominated by different eyes.(ABSTRACT TRUNCATED AT 400 WORDS)


Sign in / Sign up

Export Citation Format

Share Document