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  • 1
    Electronic Resource
    Electronic Resource
    Structure of the simple receptive field of the cat visual cortex (1981)
    Springer
    Neurophysiology 13 (1981), S. 251-255 
    Details
    ISSN: 1573-9007
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Comparison of unit responses of simple receptive fields of the cat visual cortex (area 17) to presentation of sinusoidal gratings and thin light and dark bars showed that excitatory and inhibitory on- and off-zones of the field are composed of on- and off-subfields of the lateral geniculate body converging on the cortical neuron. Each zone is formed by a pair of opposing subfields, activation of one of which gives an excitatory, and the other, an inhibitory effect. This organization is evidence that the simple field has linear properties. However, a real simple field is not a linear system because of deviations from the ideal organization described above, namely displacement of the subfields relative to each other, nonhomogeneity of the properties of the subfields, and absence of an antagonistic subfield in one of the zones. Even within the same field phasic and tonic subfields may be present.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01058658
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  • 2
    Electronic Resource
    Electronic Resource
    Types of receptive fields of the lateral geniculate body and their functional model (1975)
    Springer
    Neurophysiology 7 (1975), S. 21-26 
    Details
    ISSN: 1573-9007
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Functional differences between the type I and II receptive fields of the lateral geniculate body were studied in the cat. Some properties of these fields were shown to coincide with properties of "phasic" (Y type) and "tonic" (X type) of receptive fields. The type I fields have a limited range for transmission of information about the intensity of illumination; the type II fields, on the other hand, have a normal dynamic range of 2 log units. Using the number of spikes in groups as a measure of nervous activity, a neurophysiological scale of brightness corresponding to the psychological scale can be constructed on the basis of responses of the type II receptive field. It is postulated that type I receptive fields serve to transmit information on the shape of the image (spatial and temporal contrasts) and the type II fields transmit information on intensity of illumination. Investigation of the dynamic functional model showed that the type of receptive field is determined by the depth of inhibition through the interneuron. The depth of inhibition is much greater for type I than for type II.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01063020
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  • 3
    Electronic Resource
    Electronic Resource
    Relationship between spatial and spatial-frequency characteristics of receptive fields of cat visual cortex (1985)
    Springer
    Neuroscience and behavioral physiology 15 (1985), S. 511-519 
    Details
    ISSN: 1573-899X
    Keywords: visual cortex ; receptive field ; cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The spatial (magnitude and eccentricity) and spatial-frequency (optimum frequency and width of pass band) characteristics of the receptive fields of the cat visual cortex were investigated. It was shown that in accordance with the predictions of the theory of piecewise Fourier analysis, linear and quasilinear receptive fields of a single size comprise a modulus in each of the fields of which the index of complexity (ratio of size of field to number of periods of its optimum frequency) equals the optimum frequency multiplied by a coefficient that is constant for the given modulus. Five moduli were found with field sizes of 2.6, 3.8, 5.2, 6.2, and 7.0°, shifting with increase in the size of the modulus towards the periphery of the field of view. In accordance with predictions, when the index of complexity is fixed the width of the pass band declines inversely proportionately to the size of the fields. The obtained data directly support the hypothesis according to which the receptive fields effect a piecewise quasi-Fourier expansion of the image.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01184262
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  • 4
    Electronic Resource
    Electronic Resource
    Asymmetry of the internal connections of the striate cortex of the cat in the projection zone of the center of the field of vision (1998)
    Springer
    Neuroscience and behavioral physiology 28 (1998), S. 211-217 
    Details
    ISSN: 1573-899X
    Keywords: Cat ; striate cortex ; internal connections ; horseradish peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Studies were carried out on the organization of the internal connections of the striate cortex in cats in the projection zone of the center (0–5°) of the field of vision by microintophoretic application of horseradish peroxidase to electrophysiologically identified orientational columns. The area containing neurons showing retrograde labeling in most cases extended in the mediolateral direction. Labeled cells were located in the upper (II, III) and lower (V, VI) layers of the cortex, and the shapes and orientations of the areas containing labeled neurons in these layers coincided. Spatial asymmetry was detected in the distribution of labeled neurons relative to the orientational column studied. Labeled cells were located predominantly medial to the columns, regardless of the distance from the projection of the area centralis. Considering the visuotopical map of field 17, the asymmetry detected here provides evidence that neurons in orientational columns have more extensive connections with neurons of the peripheral part of the cortex. An asymmetrical distribution of “silent” zones around the receptive fields of neurons in orientational columns is suggested, and that these appear to receive influences from the periphery of the visual field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02461970
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  • 5
    Electronic Resource
    Electronic Resource
    Mechanism of directional sensitivity of receptive fields in the cat visual cortex (1983)
    Springer
    Neurophysiology 15 (1983), S. 178-185 
    Details
    ISSN: 1573-9007
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Responses of directional-sensitive neurons in area 17 of the cat's cortex were studied to presentation of two flashing bars of light, one located in the center of the field, the other in the inhibitory zone relative to the center. The order of activation of the stimuli and the time interval between them could be varied; presentation of two bars was thus the analog of a moving stimulus. The inhibitory off-zone located at the entrance to the field from the side of the optimal direction of movement was found to have an initial inhibitory phase, followed by a phase of disinhibition, and again by a second inhibitory phase. Presentation of the bars with different time intervals in cases when stimulation of the center of the field coincided in time with one of the inhibitory phases, led to inhibition of the response, but if stimulation coincided with the phase of disinhibition, it led to facilitation. Phases of disinhibition were not found in the inhibitory zone located at the entrance to the field along the course of a nonoptimal direction of movement. The importance of the temporal characteristics of inhibitory zones for the appearance of directional sensitivity of visual courtical neurons is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01058853
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    The uncertainty principal in vision (1986)
    Springer
    Neurophysiology 18 (1986), S. 222-226 
    Details
    ISSN: 1573-9007
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract During research into the relationship between the bandpass width of the spatial frequency characteristic (ΔF) and the size (D) of the receptive field of the cat striate cortex it was found that ΔF·D=1.2. Inaccuracy in spatial signal representation is thus related by an uncertainty principle to inaccuracy of frequency representation within the system of elements involved in information processing in the cat association cortex. The magnitude of the constant shows that the distribution functions of elements are sinusoids or cosinusoids modulated by square-wave impulses rather than Gabor elements. The magnitude of the constant and the fact that an uncertainty principle operates would support the hypothesis that the receptive fields of the visual cortex constitute a quasilinear basis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01052539
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  • 7
    Electronic Resource
    Electronic Resource
    Are receptive fields of the visual cortex detectors or spatial frequency filters? (1979)
    Springer
    Neurophysiology 11 (1979), S. 295-302 
    Details
    ISSN: 1573-9007
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Besides its principal maximum, the spatial frequency characteristic curve of the complex visual cortical receptive field of curarized cats also has additional maxima and also negative regions, as predicted by the theory of piecewise Fourier analysis. Comparison of responses of the complex receptive field to sinusoidal gratings completely and incompletely contained in the field and comparison of responses to sinusoidal and square-wave gratings indicate that the receptive field, as a spatial frequency filter, has linear properties. The response of the complex receptive field rises with an increase in the number of periods of the sinusoidal grating. Several periods of optimal frequency match the complex field. Receptive fields tuned to a broad band of spatial frequencies were found in neuron columns. The results confirm the view that complex receptive fields are spatial frequency filters and not detectors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01062990
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    Paper (German National Licenses)
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  • 8
    Electronic Resource
    Electronic Resource
    Structure of a complex receptive field in the cat visual cortex (1982)
    Springer
    Neurophysiology 14 (1982), S. 14-19 
    Details
    ISSN: 1573-9007
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The most common type of complex receptive field, whose response to the passage of sinusoidal gratings across it consisted of modulated and unmodulated components, was analyzed. The use of a mask to cover half the field, according to the filter theory, led to widening of the transmission band of the field as a spatial frequency filter, due to the appearance or enhancement of the response at lateral low and high frequencies. Modulated components of responses from the left and right halves of the field were out of phase. Analysis of this fact, and also of responses of the field to thin light and dark bars enabled the field structure to be described. It consists of linear and nonlinear subsystems, converging on the output neuron of the complex field. The former is composed of several pairs of on- and off-subfields of the lateral geniculate body. The on- and off-subfields in the pair overlap spatially and converge on the output neuron of the linear subsystem with opposite signs. The nonlinear subsystem is composed of either on- or off-subfields. Other types of complex fields may include different combinations of subsystems. The results indicate that complex fields are spatiotemporal grating filters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01058814
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    Paper (German National Licenses)
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