A Simple Analogue Teaching Device for Demonstrating Visual-Receptive-Field Properties

Perception ◽  
1988 ◽  
Vol 17 (6) ◽  
pp. 819-825
Author(s):  
Bernard Moulden ◽  
David Martin

A cheap (under £100 at current prices) and simple analogue device is described which permits one to demonstrate, according to an adjustable configuration of the photoreceptive elements, some of the main properties of (i) circularly-symmetrical, (ii) ‘simple’ elongated opponent-flank, and (iii) multiple-discharge-centre visual receptive fields. The design and construction of the device are described, together with some suggested demonstrations.

1997 ◽  
Vol 77 (5) ◽  
pp. 2268-2292 ◽  
Author(s):  
Michael S. A. Graziano ◽  
Xin Tian Hu ◽  
Charles G. Gross

Graziano, Michael S. A., Xin Tian Hu, and Charles G. Gross. Visuospatial properties of ventral premotor cortex. J. Neurophysiol. 77: 2268–2292, 1997. In macaque ventral premotor cortex, we recorded the activity of neurons that responded to both visual and tactile stimuli. For these bimodal cells, the visual receptive field extended from the tactile receptive field into the adjacent space. Their tactile receptive fields were organized topographically, with the arms represented medially, the face represented in the middle, and the inside of the mouth represented laterally. For many neurons, both the visual and tactile responses were directionally selective, although many neurons also responded to stationary stimuli. In the awake monkeys, for 70% of bimodal neurons with a tactile response on the arm, the visual receptive field moved when the arm was moved. In contrast, for 0% the visual receptive field moved when the eye or head moved. Thus the visual receptive fields of most “arm + visual” cells were anchored to the arm, not to the eye or head. In the anesthetized monkey, the effect of arm position was similar. For 95% of bimodal neurons with a tactile response on the face, the visual receptive field moved as the head was rotated. In contrast, for 15% the visual receptive field moved with the eye and for 0% it moved with the arm. Thus the visual receptive fields of most “face + visual” cells were anchored to the head, not to the eye or arm. To construct a visual receptive field anchored to the arm, it is necessary to integrate the position of the arm, head, and eye. For arm + visual cells, the spontaneous activity, the magnitude of the visual response, and sometimes both were modulated by the position of the arm (37%), the head (75%), and the eye (58%). In contrast, to construct a visual receptive field that is anchored to the head, it is necessary to use the position of the eye, but not of the head or the arm. For face + visual cells, the spontaneous activity and/or response magnitude was modulated by the position of the eyes (88%), but not of the head or the arm (0%). Visual receptive fields anchored to the arm can encode stimulus location in “arm-centered” coordinates, and would be useful for guiding arm movements. Visual receptive fields anchored to the head can likewise encode stimuli in “head-centered” coordinates, useful for guiding head movements. Sixty-three percent of face + visual neurons responded during voluntary movements of the head. We suggest that “body-part-centered” coordinates provide a general solution to a problem of sensory-motor integration: sensory stimuli are located in a coordinate system anchored to a particular body part.


1977 ◽  
Vol 40 (2) ◽  
pp. 390-409 ◽  
Author(s):  
P. D. Spear ◽  
D. C. Smith ◽  
L. L. Williams

1. Visual receptive-field characteristics were determined for 154 cells in the ventral lateral geniculate nucleus (VLG) of cats anesthetized with nitrous oxide. All cells were verified histologically to be within the VLG. Responses of 182 cells from laminae A and A1 of the dorsal lateral geniculate nucleus (DLG) were tested for comparison. 2. The VLG cells could be grouped into one of seven classes according to their responses to light stimulation. Twenty-seven percent of the cells had uniform receptive fields. They responded maximally to stationary stimuli flashed on or off anywhere within the receptive field and showed no evidence for antagonistic surround mechanisms. About 19.5% of the VLG cells had concentric receptive fields. They were similar to the uniform type, with the addition of a concentric inhibitory surround. Eight percent of the VLG cells had ambient receptive fields. These cells were characterized by an unusually regular maintained discharge which varied in rate in relation to the level of receptive-field illumination or of full-field ambient illumination. About 4% of the VLG cells were movement sensitive. They gave little or no response to stationary stimuli flashed on or off in the receptive field, and responded best to a contour moving across the receptive field in any direction. An additional 2.5% of the VLG cells were direction sensitive. Their response was dependent on the direction of stimulus movement through the receptive field. Sixteen percent of the VLG cells had indefinite receptive fields. They responded to whole-eye illumination or to localized visual-field stimulation; however, specific receptive-field properties could not be adequately defined. Approximately 23% of the VLG cells studied gave no convincing response to visual stimulation. 3. Responses of DLG cells agreed with those reported in previous studies. Almost all (97%) had concentric receptive fields, and a few (3%) had uniform receptive fields with no apparent antagonistic surround. None of the DLG cells had receptive fields like those in the other classes found for VLG cells. 4. The VLG cells tended to have large receptive fields; mean diameter was 10.6 degrees of visual arc. This was substantially larger than the diameter of receptive fields for DLG cells. In addition, VLG cells generally required larger stimuli than DLG cells to respond. There was no consistent relationship between receptive-field size and visual-field eccentricity for VLG cells, in contrast to the DLG. Most (57%) VLG cells were driven only by the contralateral eye, 30% were binocularly driven, and 13% were driven only by the ipsilateral eye. 5. A systematic visuotopic organization was present in the VLG. The lower visual field was represented anteriorly in the nucleus and the upper visual field posteriorly. The vertical meridian was represented along the dorsomedial border of the VLG where it abuts the DLG, and the temporal periphery was represented ventrolaterally. 6. Responses to electrical stimulation of the optic chiasm were studied for 55 VLG cells...


1976 ◽  
Vol 39 (3) ◽  
pp. 613-630 ◽  
Author(s):  
W. Singer ◽  
F. Tretter

An attempt was made to relate the alterations of cortical receptive fields as they result from binocular visual deprivation to changes in afferent, intrinsic, and efferent connections of the striate and parastriate cortex. The experiments were performed in cats aged at least 1 jr with their eyelids sutured closed from birth.The results of the receptive-field analysis in A17 confirmed the reduction of light-responsive cells, the occasional incongruity of receptive-field properties in the two eyes, and to some extent also the loss of orientation and direction selectivity as reported previously. Other properties common to numerous deprived receptive fields were the lack of sharp inhibitory sidebands and the sometimes exceedingly large size of the receptive fields. Qualitatively as well as quantitatively, similar alterations were observed in area 18. A rather high percentage of cells in both areas had, however, preserved at least some orientation preference, and a few receptive fields had tuning properties comparable to those in normal cats. The ability of area 18 cells in normal cats to respond to much higher stimulus velocities than area 17 cells was not influenced by deprivation.The results obtained with electrical stimulation suggest two main deprivation effects: 1) A marked decrease in the safety factor of retinothalamic and thalamocortical transmission. 2) A clear decrease in efficiency of intracortical inhibition. But the electrical stimulation data also show that none of the basic principles of afferent, intrinsic, and efferent connectivity is lost or changed by deprivation. The conduction velocities in the subcortical afferents and the differentiation of the afferents to areas 17 and 18 into slow- and fast-conducting projection systems remain unaltered. Intrinsic excitatory connections remain functional; this is also true for the disynaptic inhibitory pathways activated preferentially by the fast-conducting thalamocortical projection. The laminar distribution of cells with monosynaptic versus polsynaptic excitatory connections is similar to that in normal cats. Neurons with corticofugal axons remain functionally connected and show the same connectivity pattern as those in normal cats. The nonspecific activation system from the mesencephalic reticular formation also remains functioning both at the thalamic and the cortical level.We conclude from these and several other observations that most, if not all, afferent, intrinsic, and efferent connections of areas 17 and 18 are specified from birth and depend only little on visual experience. This predetermined structural plan, however, allows for some freedom in the domain of orientation tuning, binocular correspondence, and retinotopy which is specified only when visual experience is possible.


1986 ◽  
Vol 55 (1) ◽  
pp. 76-96 ◽  
Author(s):  
R. P. Yezierski ◽  
R. H. Schwartz

Recordings were made from 90 identified spinomesencephalic tract (SMT) cells in the lumbosacral spinal cord of cats anesthetized with alpha-chloralose and pentobarbital sodium. Recording sites were located in laminae I-VIII. Antidromic stimulation sites were located in different regions of the rostral and caudal midbrain including the periaqueductal gray, midbrain reticular formation, and the deep layers of the superior colliculus. Twelve SMT cells were antidromically activated from more than one midbrain level or from sites in the medial thalamus. The mean conduction velocity for the population of cells sampled was 45.2 +/- 21.4 m/s. Cells were categorized based on their responses to graded intensities of mechanical stimuli and the location of excitatory and/or inhibitory receptive fields. Four major categories of cells were encountered: wide dynamic range (WDR); high threshold (HT); deep/tap; and nonresponsive. WDR and HT cells had excitatory and/or inhibitory receptive fields restricted to the ipsilateral hindlimb or extending to other parts of the body including the tail, forelimbs, and face. Some cells had long afterdischarges following noxious stimulation, whereas others had high rates of background activity that was depressed by nonnoxious and noxious stimuli. Deep/tap cells received convergent input from muscle, joint, or visceral primary afferent fibers. The placement of mechanical lesions at different rostrocaudal levels of the cervical spinal cord provided information related to the spinal trajectory of SMT axons. Six axons were located contralateral to the recording electrode in the ventrolateral/medial or lateral funiculi while two were located in the ventrolateral funiculus of the ipsilateral spinal cord. Stimulation at sites used to antidromically activate SMT cells resulted in the inhibition of background and evoked responses for 22 of 25 cells tested. Inhibitory effects were observed on responses evoked by low/high intensity cutaneous stimuli and by the activation of joint or muscle primary afferent fibers. Based on the response and receptive-field properties of SMT cells it is suggested that the SMT may have an important role in somatosensory mechanisms, particularly those related to nociception.


2003 ◽  
Vol 18 (2) ◽  
pp. 449-452 ◽  
Author(s):  
Attila Nagy ◽  
Gabriella Eordegh ◽  
Masao Norita ◽  
Gyorgy Benedek

1975 ◽  
Vol 38 (2) ◽  
pp. 219-230 ◽  
Author(s):  
J. T. McIlwain

1. The receptive fields of collicular neurons in the cat, recorded in a single microelectrode penetration, were not centered on a point in visual space, but nested eccentrically with the smaller fields displaced toward the area centralis. The eccentric nesting was not eliminated by correcting the fields for the tangent screen distortion or by making penetrations normal to the collicular surface in coronal and parasagittal planes. These findings do not support the idea that collicular cells form topographically organized columns oriented normal to the collicular surface. 2. When the receptive fields were plotted in the visual coordinate system of the collicular map, the nesting became much more concentric, suggesting that the eccentric nesting of the receptive fields in visual space was largely a product of the retinotectal coordinate transformation. 3. The profile of a collicular receptive field, plotted in the collicular visual coordinate system is called the receptive-field image. Receptive-field images tended to have oval shapes with the long axis oriented mediolaterally. Clusters of receptive-field images, plotted for single penetrations, appeared similar wherever they occurred in the collicular map, suggesting that a common pattern of neural convergence determines the geometry of the receptive-field images in all parts of the colliculus. 4. The neural substrate of the receptive-field images was examined by tracing the theoretical patterns of neural activity which a point stimulus would produce in the retinotectal system. This analysis suggested that the shape and dimensions of the receptive-field images, and consequently the receptive fields, might be accounted for in large part by the geometry of collicular dendritic fields, the dimensions of the visual receptive fields of afferent fibers, and the retinotectal coordinate transformation. 5. Because it adjusts for the retinotectal distortion of visual space, the receptive-field image may be used to outline the distribution of collicular cells excited by a point stimulus. This makes it possible to show that a point stimulus activates large-field cells in the superficial gray layer over an area of about 2.5 by 1.5 mm in the central parts of the colliculus. It is suggested that such cells may organize the directional signals required by the oculomotor system for visual orienting behavior.


1978 ◽  
Vol 41 (4) ◽  
pp. 948-962 ◽  
Author(s):  
A. G. Leventhal ◽  
H. V. Hirsch

1. Receptive-field properties of neurons in the different layers of the visual cortex of normal adult cats were analyzed quantitatively. Neurons were classified into one of two groups: 1) S-cells, which have discrete on- and/or off-regions in their receptive fields and possess inhibitory side bands; 2) C-cells, which do not have discrete on- and off-regions in their receptive fields but display an on-off response to flashing stimuli. Neurons of this type rarely display side-band inhibition. 2. As a group, S-cells display lower relative degrees of binocularity and are more selective for stimulus orientation than C-cells. In addition, within a given lamina the S-cells have smaller receptive fields, lower cutoff velocities, lower peak responses to visual stimulation, and lower spontaneous activity than do the C-cells. 3. S-cells in all layers of the cortex display similar orientation sensitivities, mean spontaneous discharge rates, peak response to visual stimulation, and degrees of binocularity. 4. Many of the receptive-field properties of cortical cells vary with laminar location. Receptive-field sizes and cutoff velocities of S-cells and of C-cells are greater in layers V and VI than in layers II-IV. For S-cells, preferred velocities are also greater in layers V and VI than in layers II-IV. Furthermore, C-cells in layers V and VI display high mean spontaneous discharge rates, weak orientation preferences, high relative degrees of binocularity, and higher peak responses to visual stimulation when compared to C-cells in layers II and III. 5. The receptive-field properties of cells in layers V-VI of the striate cortex suggest that most neurons that have their somata in these laminae receive afferents from LGNd Y-cells. Hence, our results suggest that afferents from LGNd Y-cells may play a major part in the cortical control of subcortical visual functions.


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