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V D Glezer

Publications and source records attributed to V D Glezer.

27 records · Page 2Linked to original sources
PubMed1975

[Types of receptive field in the external geniculate body and its functional model].

The functional differences between receptive fields of types I and II of lateral geniculate nucleus were investigated in cat. Some characteristics of these fields are shown to coincide with transient (Y-type ) and sustanied (X-type) receptive fields. Receptive fields of type I possess a limited range for transmission of information on luminance, those of type II--a normal dynamic range (2 log. unit). The investigation of a dynamic functional model showed that type of the receptive field is determined by the depth of inhibition mediated through an interneuron. The depth of inhibition is larger in type I. Types I and II have different frequency characteristics. It is suggested that receptive fields of type I serve to transmit information on the shape of the image (spatial and time contrasts) and those of type II on luminance.

Animals↗
PubMedDate not supplied

[Adjustment of the cat visual cortex receptive fields to certain spatial frequency bands within definite ranges of movement frequencies of stimulating gratings].

Reactions of simple and composite receptive fields (RF) of the 17th and 18th fields of cat's visual cortex to grating with various spatial frequency moving through the field with different velocities were studied. It has been shown that for each RF the velocity range is revealed within which spatial-frequency selectivity of RF exists. The narrow-band tuning for high frequency RF exists in the range of low velocities, and for low frequency ones in the range of higher velocities.

Animals↗
PubMedDate not supplied

[Model of local spectral description of images in the visual system].

On the basis of experimental evidence presented earlier a model of local spectral analysis of the image performed by the complex receptive fields of the visual cortex has been proposed. An essential feature of the model is that the generalized piece-wise Fourier transform is performed not over the image luminance function but over the logarithm contrast function resulted from analysis of the image by the round receptive fields of the preceding levels. Such an assumption removes a number of experimental objections offered against the hypothesis of two-dimensional Fourier transform in the visual system. The consequencies from the piece-wise expansion in a series of basic functions have been considered and among them: the channel frequency characteristics which can have more than one maximum; the possibility of describing the image by a limited number of channels with overlapping frequency characteristics.

Fourier Analysis↗
PubMedDate not supplied

[Spatial-frequency characteristics of the receptive fields of cat visual cortex with different rates of stimulus movement].

Velocity ranges exist for complex and simple receptive fields of cat's visual cortex. In these ranges there is a narrow band frequency tuning. In these velocity ranges the location of the maximum on frequency characteristics is constant and does not depend on the velocity of stimulating lattice movement. An increase of the movement velocity brings about a reduction of the reaction value of the receptive fields and a disappearance of the narrow band tuning expressed in the optimal velocity range.

Animals↗