Showing papers on "Receptive field published in 1974"

Functional organization of a visual area in the posterior bank of the superior temporal sulcus of the rhesus monkey

Abstract: 1. Anatomical studies have shown the cortex of the posterior bank of the superior temporal sulcus to receive a projection from visual cortical areas, including areas 17, 18 and 19. In this paper the response of single neurones in this area to simple visual stimulation is reported. Ten monkeys were studied. 2. A clear but relatively crude topographic representation of the visual field was found. There was a large variation in the size of the receptive fields of individual cells, even in a single penetration. Some cells, with the central parts of their receptive fields located from between 1 and 5° from the centre of gaze had receptive fields averaging about 10° × 10° or even larger. Other cells with central receptive fields had much smaller field sizes. 3. Two main types of neurones were encountered, with subdivisions within each type. The first type responded to movement irrespective of form. These could be subdivided into neurones which responded to movement in any direction within the receptive field and neurones which responded to movement in one direction only (directionally selective neurones). Another type of cell was responsive to both contour and movement, much like the complex and lower order hypercomplex cells. Almost all such neurones were directionally selective. 4. In oblique penetrations through this cortical region, there tended frequently to be an orderly shift in preferred directions of motion, thus suggesting the possibility of a columnar organization for movement. 5. Combined anatomical (degeneration) and electrophysiological experiments showed that these types of neurones are found in those regions of the posterior bank of the superior temporal sulcus receiving a direct projection from area 17.

Uniformity of monkey striate cortex: a parallel relationship between field size, scatter, and magnification factor.

Abstract: This paper is concerned with the relationship between orientation columns, ocular-dominance columns, the topographic mapping of visual fields onto cortex, and receptive-field size and scatter. Although the orientation columns are an order of magnitude smaller than the ocular-dominance columns, the horizontal distance corresponding to a complete cycle of orientation columns, representing a rotation through 180°, seems to be roughly the same size as a left-plus-right ocular dominance set, with a thickness of about 0.5–1 mm, independent of eccentricity at least out to 15°. We use the term hypercolumn to refer to a complete set of either type (180°, or left-plus-right eyes). In the macaque monkey several penetrations were made at various eccentricities in various parts of the striate cortex subserving the fovea, parafovea and midperiphery. As observed many times previously, in any vertical penetration there was an apparently random scatter in receptive-field positions, which was of the same order of magnitude as the individual receptive fields in that part of the cortex; the field size and the scatter increased in parallel fashion with eccentricity. The movement through the visual field corresponding to a 1 mm horizontal movement along the cortex (the reciprocal of the magnification factor) also increased with eccentricity, in a manner that was strikingly parallel with the increase in receptive field size and scatter. In parts of the cortex representing retina, at least out to about 22° from the fovea, a movement along the cortical surface of about 1 mm was enough to displace the fields so that the new position they collectively occupied half overlapped the old. Such an overlap was thus produced by moving along the cortex a distance about equal to the thickness of a left-plus-right set of ocular-dominance columns, or a complete 180° array of orientation columns. It therefore seems that, independent of eccentricity, a 2 mm × 2 mm block of cortex contains by a comfortable margin the machinery needed to analyze a region of visual field roughly equal to the local field size plus scatter. A movement of 2–3 mm corresponds to a new visual field region and to several new sets of hypercolumns. The cortex thus seems remarkably uniform physiologically, just as it is anatomically.

Properties of rarely encountered types of ganglion cells in the cat's retina and on overall classification

Abstract: 1. In a reference sample of 960 cat retinal ganglion cells, seventy-three had receptive fields departing from the concentric centre—surround pattern. 2. Five classes were distinguished among the subset: local edge detectors, direction-selective cells, colour-coded cells, uniformity detectors, edge inhibitory off-centre cells. 3. Local edge detectors (forty-five) possessed a radially symmetrical pattern of responses to both centrifugal and centripetal movements of both black and white small targets, an on—off receptive field with a silent inhibitory surround and a low or zero maintained discharge. Their operation could be interpreted as the detection of a contrasting border confined to a small region of the visual field. 4. With direction-selective units (eleven) it was possible to find an axis through the receptive field along which sharply different responses could be obtained for opposite directions of movement of small black or white targets. 5. Colour units (six) were mostly of the single opponent type having excitatory input from blue-sensitive cones and inhibitory input from long wave-length cones. Both inputs coexisted at the centre of the field and either could be spatially more extensive than the other. One example changed over to rod input under scotopic conditions, another did not. 6. Uniformity detectors (five) had a brisk maintained discharge which was reduced or abolished temporarily by all forms of visual stimulation. 7. Edge inhibitory off-centre units (three) behaved like uniformity detectors for small targets and fine gratings but like off-centre on-surround units for large targets. Their receptive fields consisted of three concentric regions: a small sized, central edge inhibitory region; a larger zone of off-responsiveness; and an outlying annulus of on-responsiveness. 8. It is argued that the above physiological types belong to the morphologically heterogeneous class of cells called γ cells. The argument is based on similarity in the sizes of receptive fields and dendritic trees and on evidence that the axons are thinner than those of the brisk-sustained and brisk-transient ganglion cells. 9. The physiological classification of cat retinal ganglion cells developed in this paper and the preceding one is summarized in a Table. 10. It now appears that cat and rabbit possess a qualitatively similar complement of receptive field types among their ganglion cells; the differences reside in the quantitative expression of the various classes.

The effect of visual experience on the development of stimulus specificity by kitten cortical neurones.

Abstract: 1. 284 single cortical neurones were studied in area seventeen of twenty-five normal kittens and of fifteen kittens, binocularly deprived, whose first visual experience had been delayed until the experiment by bilateral lid-suture. Both normal and binocularly deprived kittens ranged in age from 1 to 6 weeks. 2. The optimal, binocularly presented, visual stimulus and receptive fields were determined for each neurone by varying target configuration, speed and direction of movement and the prism-induced alignment of both eyes. Repetitive, controlled stimulation in eighty-four cases allowed quantitative estimates to be made of the response selectivity for the target configuration (spot vs. line), the direction of target motion and the prism-induced disparity between the retinal images of the binocular target. 3. Before the fourth post-natal week neurones from both normal and binocularly deprived cortex showed similar properties: selectivity for direction of target motion was present in both preparations but both lacked binocular specificity and dependence on target configuration. 4. After the fourth week, normal kittens had increasing numbers of neurones with selective responses which were dependent upon target configuration and the degree of binocular misalignment. The proportion of selective neurones approached the adult value after the fifth week. 5. The cortex of binocularly deprived kittens failed to show an increase of selectivity with age, and of 150 neurones, sixty-two were visually unresponsive, two showed selectivity which was dependent upon target configuration and none showed selectivity for prism-induced retinal disparity. 6. The data are not consistent with the hypothesis that the highly specific response properties of visual cortical neurones can develop without appropriate visual experience. Innate mechanisms appear to be sufficient for the development of the excitatory connexions producing motion sensitivity and receptive field location on both retinas, but patterned visual experience is necessary for the ‘fine-tuning’ which vetoes responses to stimuli with non-optimal configuration or binocular disparity.

Cell structure and function in the visual cortex of the cat

Abstract: 1 The organization of the visual cortex was studied with a technique that allows one to determine the physiology and morphology of individual cells Micro-electrodes filled with the fluorescent dye Procion yellow were used to record intracellularly from cells in area 17 of the cat The visual receptive field of each neurone was classified as simple, complex, or hypercomplex, and the cell was then stained by the iontophoretic injection of dye 2 Fifty neurones were successfully examined in this way, and their structural features were compared to the varieties of cell types seen in Golgi preparations of area 17 The majority of simple units were stellate cells, whereas the majority of complex and hypercomplex units were pyramidal cells Several neurones belonged to less common morphological types, such as double bouquet cells Simple cells were concentrated in layer IV, hypercomplex cells in layer II + III, and complex cells in layers II + III, V and VI 3 Electrically inexcitable cells that had high resting potentials but no impulse activity were stained and identified as glial cells Glial cells responded to visual stimuli with slow graded depolarizations, and many of them showed a preference for a stimulus orientation similar to the optimal orientation for adjacent neurones 4 The results show that there is a clear, but not absolute correlation between the major structural and functional classes of cells in the visual cortex This approach, linking the physiological properties of a single cell to a given morphological type, will help in furthering our understanding of the cerebral cortex

Neural Basis of Orientation Perception in Primate Vision

Abstract: Orientational differences in human visual acuity can be related parametrically to the distribution of optimal orientations for the receptive fields of neurons in the striate cortex of the rhesus monkey. Both behavioral measures of acuity and the distribution of receptive fields exhibit maximums for stimuli horizontal or vertical relative to the retina; the effect diminishes with distance from the fovea. The anisotropy in the neuronal population and in visual acuity appear to be determined by postnatal visual experience.

The Evolution of the Retinotectal Map during Development in Xenopus

Abstract: The retinotectal projection was mapped electrophysiologically in tadpoles of Xenopus laevis. Recording was performed with the animals immersed in saline inside a transparent hemisphere. Visual responses could be recorded from the optic tectum from about stage 43 onwards. The visual map on the tectum of the tadpole was found to differ in several respects from that in the adult. The earliest responses recorded showed very large multi-unit receptive fields and no discernible retinotopic organization. From about stage 47 the map showed the adult type of order; nasal field projected rostrally, temporal field caudally, superior field medially and inferior field laterally. However, in tadpoles up to stage 63/64 the projection was markedly distorted in that nasal field was confined to the most rostral region of the tectum and there was an expanded representation of the temporal pole of the field. In tadpoles the entire visual projection covers only the rostral one-half to two-thirds of the tectum. These results, in conjunction with the results of previous studies on the mode of growth of the retina and tectum, indicate a progressive shift of the retinotectal projection with development which may involve changing synaptic relations between retinal fibres and tectal cells.

Control of Retinal Sensitivity : II. Lateral Interactions at the Outer Plexiform Layer

Abstract: Test stimuli, presented at the center of the bipolar cell receptive field, spanning less than 2 log units of intensity, elicit the full range of graded response. The intensity range of test stimuli that elicits the graded response depends upon the background conditions. A higher range of log test intensities is required to elicit the graded bipolar response in the presence of surround backgrounds. But surround backgrounds can also serve to unsaturate the bipolar response and thereby increase sensitivity under certain conditions. The results suggest that a second stage of sensitivity-control is mediated by the horizontal cell system at the outer plexiform layer, concatenated with the effects of adaptation in the photoreceptors.

Cells responding to changing image size and disparity in the cortex of the rhesus monkey

Abstract: 1. The cells of the cortex of the posterior bank of the superior temporal sulcus of the monkey appear to be specialized to signal motion in the visual field. In this paper, cells in this cortical area capable of signalling motion towards or away from the animal are described. 2. Two such types of cell were encountered. One type, the opposed movement complex and opposed movement hypercomplex cells, responded to two edges at a given orientation moving towards or away from each other within the receptive fields. These cells were driven either monocularly or binocularly, but when binocularly driven the cells responded in an identical manner to stimulation of each eye, thus suggesting that such cells must receive a double, and opposed, input from each eye. The other type of cell, always binocularly driven, responded to movement in opposite directions on the two retinas, thus suggesting that such cells must receive diametrically opposite connexions from the two eyes. 3. Long penetrations made to study the manner in which such cells were grouped together in the cortex revealed that they were arranged in small groups or clusters, separated from each other by the common directionally selective cells so prominently present in this area. Thus, cells with one type of wiring mechanism were separated from each other by cells receiving another, and more common, type of anatomical wiring.

Cat retinal ganglion cells: size and shape of receptive field centres.

Abstract: 1. Receptive field centres of 144 sustained and transient retinal ganglion cells were mapped in cats under light pentobarbitone anaesthesia.2. Sustained on-centre, sustained off-centre, transient on-centre and transient off-centre cells had different mean sizes of receptive field centre, with some overlap between their distributions.3. For each class of cell, central fields had the smallest field-centres; progressively larger field-centres were encountered more peripherally.4. All classes of ganglion cells tended to have slightly elliptical receptive field centres. Major axes of over half of all receptive fields were oriented within 20 degrees of horizontal. These trends were independent of pupil dimensions, or of receptive field eccentricity or position in the visual field. The results almost certainly reflect asymmetry in retinal wiring.5. Two cells of thirty-nine tested were sensitive to axis of motion; in both cases the preferred and major axis were horizontal. A further cell was orientation specific.

Responses of bipolar cells in the retina of the turtle

Abstract: The responses of bipolar cells in the retina of the turtle have been studied by intracellular recording. Two types of bipolar cell have been identified: one gave graded depolarizing and the other graded hyperpolarizing responses to small circles of light (100 μm diameter). The responses of both types of cell were similar in the following respects. 1. Both were extremely sensitive to dim light; the amplitude of response to a small circle of light increased with light intensity more steeply than the cone response. 2. Enlarging the diameter of a spot added an antagonistic effect which decreased response amplitude. This decrease in response amplitude was more apparent at dim than at bright light. Stimulating only distant areas of retina with an annulus produced a response of polarity opposite to that normally produced by a central spot. However, the responses of bipolar cells did not appear to be due to a simple summation of opposite polarity signals contributed from central and peripheral parts of their receptive fields. 3. When small spots or annuli of light were turned off there frequently occurred an overshooting OFF transient. The occurrence of OFF transients depended on the duration of the stimulus. Cones recorded under similar conditions produced an OFF depolarization. The size of cone OFF depolarizations increased with increasing duration of the preceding light; following approximately 3 sec of illumination their maximum amplitude was roughly 1/10 the amplitude of the preceding hyperpolarization. The size of OFF responses in both cone and bipolar cells was increased when horizontal cells were hyperpolarized by light. It is concluded that bipolar cells produce large responses for very small cone responses, and, as a consequence, a small depolarization in cones following illumination produces large OFF transients in bipolar cells. Furthermore, the responses of bipolar cells do not appear to represent a simple summation of opposite polarity input from receptor and horizontal cells.

The orientation selectivity of single neurons in cat striate cortex

Abstract: The sensitivity to stimulus orientation — orientation selectivity — of simple and complex neurons in cat striate cortex was studied quantitatively. Orientation selectivity was found to be related to receptive field size — neurons with larger receptive fields being less sensitive to stimulus orientation than those with smaller receptive fields. Simple cells were more orientationally selective than complex cells. The orientation selectivity of simple cells was only weakly related to their receptive field geometry (i.e., receptive field width/length ratio), but simple cells with narrow, elongated excitatory receptive fields are more orientationally selective than those with squarer, excitatory receptive fields. These results indicate that orientation selectivity cannot be accounted for solely by the geometry of the excitatory zones and suggest that inhibitory influences sharpen the tuning of simple striate neurons for stimulus orientation.

Vertical organization in the visual cortex (area 17) in the cat.

Abstract: 1. Responses of cortical cells in the cat's area 17 (central and paracentral area), recorded successively during electrode penetrations perpendicular to the surface, were averaged (PSTH). All cells recorded during one penetration were stimulated with the same stimulus, a slowly moving light or dark slit oriented optimally for the first cell recorded. Comparisons between successively recorded cells were completed by simultaneous recordings from two neurones with the same microelectrode tip. Eye movements as an error were excluded by simultaneous recording of a geniculate cell throughout a cortical penetration. 2. The centers of excitatory receptive fields (ERFs) of simultaneously or successively recorded cells during a penetration may be separated by more than 4°. The mean scatter around a column average is 0.81±0.99° in both directions. The scatter is independent of the recording depth. Whereas the optimal orientation of cells recorded during one penetration was generally similar, the optimal direction (forward and backward movement of an optimally oriented stimulus) was variable. 3. The ERF diameters as determined from the PSTH were between 3.0°) ERFs could be discriminated. The inhibitory fields (determined with the conditioning method of Bishop, Coombs and Henry, 1971) were between 2.0 and 8.5° along both the optimal and the non-optimal orientation axis of a cell. The borders of inhibitory fields of cells collected during one penetration were also scattered though overlapping. 4. Response analysis of simultaneously and successively recorded cells with different stimuli indicated that, in spite of considerable ERF-overlap, cells with small ERFs had separate excitatory inputs and that intracortical excitatory connections between cells recorded during one penetration were improbable. 5. The ERFs of cells with large ERFs covered a field approximately corresponding to the fields of cells with small ERFs. But a convergent input from many small ERF cells to single large ERF cells was excluded because of the incompatible functional properties of both types of cells, which correspond to some extent to simple and complex cells respectively. 6. It is concluded that cells within cortical cylinders are not connected through excitatory contacts with each other and that most cells in area 17 are excited by individual excitatory geniculate or cortical inputs. Inhibitory connections seem to be the most important intracortical connections. 7. In an Appendix it is shown that anatomical and physiological data do not support significant excitatory convergence of specific geniculate afferents on cortical neurones.

Patterns of the somesthetic messages transferred through the corpus callosum.

Abstract: 1. In the rostral part of the corpus callosum (somesthetic callosal region, SCR) fibres were identified, through which the callosally-projecting cells of the somatosensory areas transmit to the other hemisphere signals originated in the body surface. 2. With seriate macroelectrode penetrations it was found that, to some extent, the body surface is represented somatotopically in the rostrocaudal extent of the SCR. The strongest mass potentials to trigeminal, fore- and hindlimb stimulation were recorded from the rostral, middle and caudal portions of the SCR. The whisker region and the forelimb (both paws and proximal segments) appeared to have the widest callosal representation. 3. Ablation experiments showed that callosal somesthetic fibres originate in both SI and SII areas and that only impulses set up in the contralateral hemibody are relayed in these areas. Direct stimulation of the latter evoked within the SCR mass potentials whose rostrocaudal distribution parallels that of the peripherally evoked responses. 4. Exploring the SCR with microelectrodes, 43 spontaneously active fibres were isolated, all reactive to electrical and physiological stimulation of the related peripheral receptive fields. These were located in trigeminal (31 fibres), segmental (10 fibres) or both in trigeminal and segmental regions (2 fibres). The extent of the receptive fields and the reactivity characteristics of almost all the fibres sampled were lemniscal in type, and similar to those of the somatotopic neurones of cortical somatosensory areas.

Intraretinal differentiation in the synaptic organization of the inner plexiform layer of the pigeon retina

Abstract: The inner plexiform layer at ten retinal loci in pigeon was examined by electron microscopy. Photomontages of the entire depth of the inner plexiform layer at each locus were analyzed with respect to the number of amacrine and bipolar synapses, their respective ratios, synaptic densities, percent amacrine synapses in serial configuration, synaptic layering patterns, and the effect of staining procedures on these quantities. The results show that the pigeon retina is not homogeneous regarding the structural complexity of the inner plexiform layer, but may be divided into four general areas in decreasing order of complexity: red field, temporal yellow field, nasal yellow field, and the area centralis. Significant differences in the amacrine synapse to bipolar synapse ration and amacrine synaptic density were observed across the retina, while bi-polar synaptic density and the percent of serial synapses were rather constant. Amacrine synapses displayed a layering pattern which was consistent throughout the retina; while bipolar synapses showed two patterns. It was further observed that the density of amacrine and bipolar synapses bears little relationship to the density of amacrine and bipolar cells in the immediately overlying inner nuclear layer. This suggests that the various retinal loci may be characterized by different proportions of the morphological types of amacrine and bipolar cells present in the pigeon retina. Based on recent studies which have shown that a relationship exists between the complexity of ganglion cell receptive fields and the synaptic complexity of the inner plexiform layer, it is suggested that the ganglion cells of pigeon would show a physiological differentiation among retinal loci consistent with the observed differences in the anatomical complexity of the inner plexiform layer.

Effects of glutamate and GABA on specific response properties of neurones in the visual cortex.

Abstract: Changes of specific response properties of single neurones in area 17 of the cat's cortex were studied during electrophoretic administration of glutamate and gamma-aminobutyric acid (GABA). Most cells were excited by glutamate. The diameter of the cells' discharge field (ERF) was enlarged by less than 1° in most cells, and the amplitude of the response within the ERF was increased. There was a weak correlation between the original size of the ERF and its enlargement during glutamate. Stimuli presented in non-optimal orientations and moved in the non-optimal direction became also effective in eliciting an excitatory response. When glutamate “doses” sufficiently high to increase background activity were used, inhibitory regions of the receptive fields could be revealed. GABA decreased the excitability of the cells until the response was totally blocked. In some cases, glutamate also decreased the excitability of cells. Simultaneous recordings from two cells suggested that the inhibitory effect may be indirect through activation of nearby inhibitory neurones. It is pointed out that extracellular recording combined with electrophoretic administration of glutamate can reveal information about a cell's properties which can otherwise only be obtained with intracellular recordings. The functional implications of the results are discussed.

A study of single axons in the cat's medial lemniscus.

Abstract: 1. A method was developed for locating the rostral part of the medial lemniscus in anaesthetized cats and then exploring it with a micro-electrode selective for single axons. Records were made from 165 axons, all shown histologically to lie in the lemniscus. 2. Almost all lemniscal axons responded at short latency to a shock through surface electrodes over the dorsal columns at C2. The great majority probably belonged to the dorsal column-lemniscal system, though some may have belonged to other (e.g. spinocervicothalamic) systems. 3. Resting discharge was seen in almost all axons in the absence of any stimulation, and must have been generated almost entirely in the relevant relay nuclei, particularly since in many axons it was easily depressed or totally inhibited by appropriately placed mechanical stimulation of skin or a shock to the dorsal columns. 4. For each fibre held for an adequate length of time, the receptive field, if accessible, was classified as accurately as possible. Fifty-two axons were precisely categorized in this way: many more were studied for long enough to yield useful information. 5. One half (twenty-six) of the best categorized axons had receptive fields suggesting excitation by only one type of receptor: fifteen by tylotrich hairs, four by rapidly adapting tactile foot pad receptors, two by claw movement, two by cutaneous touch corpuscles and three by Type II cutaneous receptors. Rigidly held probes driven by electromechanical transducers were used to establish stimulus/response relations. Adjacent or surround inhibition was seen in nearly all these fields, except for the Type II category. 6. The other half (twenty-six) of the best categorized axons showed various degrees of inter-receptive excitatory convergence. Five responded to all types of hair, twelve to hair movement and foot-pad displacement, and nine to hair movement combined with inputs from a variety of slowly adapting receptors in skin or deep tissues, thresholds for the latter ranging from light contact to noxious pressure. 7. Forty axons responded with a slowly adapting discharge to joint movement, some with properties suggesting that their receptors did not lie in the joint capsule itself. The high threshold of most of these axons to dorsal column stimulation suggested that the relevant primary axons lay either deep in the dorsal column or in some other tract. 8. Of axons whose receptive fields were accurately located, 88% lay in forelimb or upper trunk — the remainder in lower trunk, hind limb or tail. The forepaw accounted for 41% of the former group. Axons with receptively `pure' properties tended to lie in central or deep parts of the main lemniscal mass at the level studied. Axons responding to joint movement tended to lie deep in the main mass and in the ventromedial lemniscal bundle. There was some clustering of axons with identical receptive properties.

Binocular neurons of the rabbit's visual cortex: receptive field characteristics.

Abstract: Using standard electrophysiological techniques, 130 neurons were recorded from the binocular region of the paralysed, unanesthetised rabbit's visual cortex Their receptive fields were categorised into 5 major classes: stationary, motion sensitive, direction selective, double-direction selective and indefinite The majority of the preferred directions of all direction and double direction selective receptive fields were located within±10° of horizontal or vertical Of the 130 neurons studied, 104 (79%) were binocular and 50% of these binocular neurons had non-identical receptive fields on the two retinae The dominance distribution for these binocular neurons revealed a strong tendency toward contralateral dominance, and no ipsilateral monocular neurons were found The retinal locations of the receptive fields of these binocular neurons extended from 51° to 84° posterior to the optic disc The ranges of relative horizontal and vertical “disparity” were calculated for all well-defined binocular receptive fields and found to be 245° and 21°, respectively No evidence of “columnar organisation” was seen for the visual cortex of the rabbit These data are contrasted to similar data on the binocular visual system of the cat, and are also interpreted as evidence of the need for interactions among large populations of neurons within the visual cortex of the rabbit