scholarly journals Topographic organization of the “third tier” dorsomedial visual cortex in the macaque

2019 ◽  
Author(s):  
Kostas Hadjidimitrakis ◽  
Sophia Bakola ◽  
Tristan A. Chaplin ◽  
Hsin-Hao Yu ◽  
Omar Alanazi ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Visual Processing ◽  
Large Scale ◽  
Receptive Fields ◽  
Topographic Map ◽  
Lower Quadrant ◽  
Functional Studies ◽  
The Third ◽  
Upper Visual Field

AbstractThe boundaries of the visual areas located anterior to V2 in the dorsomedial region of the macaque cortex remain contentious. This region is usually conceptualized as including two functional subdivisions: the dorsal component of area V3 (V3d), laterally, and another area, named the parietooccipital area (PO) or V6, medially. However, the nature of the putative border between V3d and PO/V6 has remained undefined. We recorded the receptive fields of multiunit clusters in adult male macaques, and reconstructed the locations of recording sites using histological sections and “unfolded” cortical maps. Immediately adjacent to dorsomedial V2 we observed a representation of the lower contralateral quadrant, which represented the vertical meridian at its rostral border. This region, corresponding to V3d of previous studies, formed a simple eccentricity gradient, from approximately <5° in the annectant gyrus, to >60° in the parietooccipital sulcus. However, there was no topographic reversal where one would expect to find the border between V3d and PO/V6. Rather, near the midline, this lower quadrant map continued directly into a representation of the peripheral upper visual field, without an intervening lower quadrant representation that could be unambiguously assigned to PO/V6. Thus, V3d and PO/V6 form a continuous topographic map, which includes parts of both quadrants. Together with previous observations that V3d and PO/V6 are both densely myelinated relative to adjacent cortex, and share similar input from V1, these results suggest that they are parts of a single area, which is distinct from the one forming the ventral component of the third tier complex.Significance statementThe primate visual cortex has a large number of areas. Knowing the extent of each visual area, and how they can be distinguished from each other, are essential for the interpretation of experiments aimed at understanding visual processing. Currently, there are conflicting models of the organization of the dorsomedial visual cortex rostral to area V2 (one of the earliest stages of cortical processing of vision). By conducting large-scale electrophysiological recordings, we found that what were originally thought to be distinct areas in this region (dorsal V3, and the parietooccipital area [PO/V6]), together form a single map the visual field. These results will help guide future functional studies, and the interpretation of the outcomes of lesions involving the dorsal visual cortex.

Comparison of Human Occipital Cortical Activation to Lower and Upper Visual Field Stimuli

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 319-319
Author(s):  
K Portin ◽  
S Vanni ◽  
R Hari
Keyword(s):  
Visual Field ◽  
Visual Processing ◽  
Cortical Activation ◽  
Field Stimulation ◽  
Evoked Responses ◽  
Black Dot ◽  
Lower Field ◽  
Lower Quadrant ◽  
Upper Visual Field ◽  
Source Current

We compared cortical responses to lower and upper quadrant and full hemifield stimuli (90° and 180° sectors of circular checkerboards) measured from 15 healthy subjects with a Neuromag-122™ whole-scalp neuromagnetometer. The 0.2 s stimuli were presented once every second, while the subjects fixated a black dot in the centre of the screen. The first evoked responses, peaking at 70 ms in the contralateral hemisphere, were stronger for lower than for upper field stimulation (13/15 subjects, LVF; 11/15 RVF). The sources of the evoked responses, modelled as equivalent current dipoles, clustered around the calcarine fissure, with a trend for stronger sources after lower than after upper field stimulation (on average 12% LVF; 40% RVF; ns). Attention-related visual processing may be enhanced in the lower compared with the upper visual field (Rubin et al, 1996 Science271 651 – 653). Although our data showed a strong tendency to larger responses for lower than for upper visual field stimuli, this difference was not significant for source strengths, mainly because of different source depths for upper and lower field stimuli. However, the marked similarity of source current directions for full hemifield and lower quadrant stimuli (15° - 35° upwards from the horizontal axis, viewed from back, compared with directions 15° - 25° downwards for upper field stimuli) suggest that visual input from the lower field is preferred already at early stages of the human visual system.

Ferrier lecture - Functional architecture of macaque monkey visual cortex

1977 ◽  
Vol 198 (1130) ◽  
pp. 1-59 ◽  
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Receptive Field ◽  
Striate Cortex ◽  
Single Cells ◽  
Ocular Dominance ◽  
Receptive Fields ◽  
Macaque Monkey ◽  
Area 17 ◽  
Orientation Specificity

Of the many possible functions of the macaque monkey primary visual cortex (striate cortex, area 17) two are now fairly well understood. First, the incoming information from the lateral geniculate bodies is rearranged so that most cells in the striate cortex respond to specifically oriented line segments, and, second, information originating from the two eyes converges upon single cells. The rearrangement and convergence do not take place immediately, however: in layer IVc, where the bulk of the afferents terminate, virtually all cells have fields with circular symmetry and are strictly monocular, driven from the left eye or from the right, but not both; at subsequent stages, in layers above and below IVc, most cells show orientation specificity, and about half are binocular. In a binocular cell the receptive fields in the two eyes are on corresponding regions in the two retinas and are identical in structure, but one eye is usually more effective than the other in influencing the cell; all shades of ocular dominance are seen. These two functions are strongly reflected in the architecture of the cortex, in that cells with common physiological properties are grouped together in vertically organized systems of columns. In an ocular dominance column all cells respond preferentially to the same eye. By four independent anatomical methods it has been shown that these columns have the form of vertically disposed alternating left-eye and right-eye slabs, which in horizontal section form alternating stripes about 400 μm thick, with occasional bifurcations and blind endings. Cells of like orientation specificity are known from physiological recordings to be similarly grouped in much narrower vertical sheeet-like aggregations, stacked in orderly sequences so that on traversing the cortex tangentially one normally encounters a succession of small shifts in orientation, clockwise or counterclockwise; a 1 mm traverse is usually accompanied by one or several full rotations through 180°, broken at times by reversals in direction of rotation and occasionally by large abrupt shifts. A full complement of columns, of either type, left-plus-right eye or a complete 180° sequence, is termed a hypercolumn. Columns (and hence hypercolumns) have roughly the same width throughout the binocular part of the cortex. The two independent systems of hypercolumns are engrafted upon the well known topographic representation of the visual field. The receptive fields mapped in a vertical penetration through cortex show a scatter in position roughly equal to the average size of the fields themselves, and the area thus covered, the aggregate receptive field, increases with distance from the fovea. A parallel increase is seen in reciprocal magnification (the number of degrees of visual field corresponding to 1 mm of cortex). Over most or all of the striate cortex a movement of 1-2 mm, traversing several hypercolumns, is accompanied by a movement through the visual field about equal in size to the local aggregate receptive field. Thus any 1-2 mm block of cortex contains roughly the machinery needed to subserve an aggregate receptive field. In the cortex the fall-off in detail with which the visual field is analysed, as one moves out from the foveal area, is accompanied not by a reduction in thickness of layers, as is found in the retina, but by a reduction in the area of cortex (and hence the number of columnar units) devoted to a given amount of visual field: unlike the retina, the striate cortex is virtually uniform morphologically but varies in magnification. In most respects the above description fits the newborn monkey just as well as the adult, suggesting that area 17 is largely genetically programmed. The ocular dominance columns, however, are not fully developed at birth, since the geniculate terminals belonging to one eye occupy layer IVc throughout its length, segregating out into separate columns only after about the first 6 weeks, whether or not the animal has visual experience. If one eye is sutured closed during this early period the columns belonging to that eye become shrunken and their companions correspondingly expanded. This would seem to be at least in part the result of interference with normal maturation, though sprouting and retraction of axon terminals are not excluded.

scholarly journals Variations in photoreceptor throughput to mouse visual cortex and the unique effects on tuning

2020 ◽  
Author(s):  
I. Rhim ◽  
G. Coello-Reyes ◽  
I. Nauhaus
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Adaptive Filtering ◽  
Frequency Tuning ◽  
Cortical Circuits ◽  
Spatial Frequency Tuning ◽  
Upper Visual Field ◽  
Spatio Temporal ◽  
Mouse Visual Cortex ◽  
Common Laboratory

ABSTRACTVisual input to primary visual cortex (V1) depends on highly adaptive filtering in the retina. In turn, isolation of V1 computations to study cortical circuits requires control over retinal adaption and its corresponding spatio-temporal-chromatic output. Here, we first measure the balance of input to V1 from the three main photoreceptor opsins – M-opsin, S-opsin, and rhodopsin – as a function of light adaption and retinotopy. Results show that V1 is rod-mediated in common laboratory settings, yet cone-mediated in natural daylight, as evidenced by exclusive sensitivity to UV wavelengths via cone S-opsin in the upper visual field. Next, we show that cone-mediated V1 responds to 2.5-fold higher temporal frequencies than rod-mediated V1. Furthermore, cone-mediated V1 has smaller RFs, yet similar spatial frequency tuning. V1 responses in rod-deficient (Gnat1−/−) mice confirm that the effects are due to differences in photoreceptor contribution. This study provides foundation for using mouse V1 to study cortical circuits.

Interocular torsional disparity and visual cortical development in the cat

1990 ◽  
Vol 64 (4) ◽  
pp. 1352-1360 ◽  
Author(s):  
M. R. Isley ◽  
D. C. Rogers-Ramachandran ◽  
P. G. Shinkman
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Ocular Dominance ◽  
Visual Fields ◽  
Receptive Fields ◽  
Right Visual Field ◽  
Orientation Columns ◽  
Areas 17 And 18 ◽  
The Right ◽  
Visual Cortical

1. The present experiments were designed to assess the effects of relatively large optically induced interocular torsional disparities on the developing kitten visual cortex. Kittens were reared with restricted visual experience. Three groups viewed a normal visual environment through goggles fitted with small prisms that introduced torsional disparities between the left and right eyes' visual fields, equal but opposite in the two eyes. Kittens in the +32 degrees goggle rearing condition experienced a 16 degrees counterclockwise rotation of the left visual field and a 16 degrees clockwise rotation of the right visual field; in the -32 degrees goggle condition the rotations were clockwise in the left eye and counterclockwise in the right. In the control (0 degree) goggle condition, the prisms did not rotate the visual fields. Three additional groups viewed high-contrast square-wave gratings through Polaroid filters arranged to provide a constant 32 degrees of interocular orientation disparity. 2. Recordings were made from neurons in visual cortex around the border of areas 17 and 18 in all kittens. Development of cortical ocular dominance columns was severely disrupted in all the experimental (rotated) rearing conditions. Most cells were classified in the extreme ocular dominance categories 1, 2, 6, and 7. Development of the system of orientation columns was also affected: among the relatively few cells with oriented receptive fields in both eyes, the distributions of interocular disparities in preferred stimulus orientation were centered near 0 degree but showed significantly larger variances than in the control condition.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Spatiotemporal adaptation through corticothalamic loops: A hypothesis

2000 ◽  
Vol 17 (1) ◽  
pp. 107-118 ◽  
Author(s):  
ULRICH HILLENBRAND ◽  
J. LEO van HEMMEN
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Lateral Geniculate Nucleus ◽  
Sensory Processing ◽  
Object Segmentation ◽  
Receptive Fields ◽  
The Novel ◽  
Spatiotemporal Structure ◽  
Cortical Responses ◽  
Cortical Receptive Fields

The thalamus is the major gate to the cortex and its control over cortical responses is well established. Cortical feedback to the thalamus is, in turn, the anatomically dominant input to relay cells, yet its influence on thalamic processing has been difficult to interpret. For an understanding of complex sensory processing, detailed concepts of the corticothalamic interplay need yet to be established. Drawing on various physiological and anatomical data, we elaborate the novel hypothesis that the visual cortex controls the spatiotemporal structure of cortical receptive fields via feedback to the lateral geniculate nucleus. Furthermore, we present and analyze a model of corticogeniculate loops that implements this control, and exhibit its ability of object segmentation by statistical motion analysis in the visual field.

scholarly journals Mouse retinal specializations reflect knowledge of natural environment statistics

2020 ◽  
Author(s):  
Yongrong Qiu ◽  
Zhijian Zhao ◽  
David Klindt ◽  
Magdalena Kautzky ◽  
Klaudia P. Szatko ◽  
...  
Keyword(s):  
Visual Field ◽  
Visual Processing ◽  
Natural Scenes ◽  
Lower Visual Field ◽  
Natural Scene Statistics ◽  
Predator Detection ◽  
Chromatic Contrast ◽  
Enhanced Sensitivity ◽  
Upper Visual Field ◽  
Environmental Difference

SummaryPressures for survival drive sensory circuit adaption to a species’ habitat, making it essential to statistically characterise natural scenes. Mice, a prominent visual system model, are dichromatic with enhanced sensitivity to green and UV. Their visual environment, however, is rarely considered. Here, we built a UV-green camera to record footage from mouse habitats. We found chromatic contrast to greatly diverge in the upper but not the lower visual field, an environmental difference that may underlie the species’ superior colour discrimination in the upper visual field. Moreover, training an autoencoder on upper but not lower visual field scenes was sufficient for the emergence of colour-opponent filters. Furthermore, the upper visual field was biased towards dark UV contrasts, paralleled by more light-offset-sensitive cells in the ventral retina. Finally, footage recorded at twilight suggests that UV promotes aerial predator detection. Our findings support that natural scene statistics shaped early visual processing in evolution.Lead contactFurther information and requests for resources and reagents should be directed to and will be fulfilled by the Lead Contact, Thomas Euler ([email protected])

scholarly journals Typical visual-field locations enhance processing in object-selective channels of human occipital cortex

2018 ◽  
Vol 120 (2) ◽  
pp. 848-853 ◽  
Author(s):  
Daniel Kaiser ◽  
Radoslaw M. Cichy
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Functional Mri ◽  
Object Perception ◽  
Occipital Cortex ◽  
Natural Environments ◽  
Lower Visual Field ◽  
Cortical Processing ◽  
Upper Visual Field ◽  
Early Visual Cortex

Natural environments consist of multiple objects, many of which repeatedly occupy similar locations within a scene. For example, hats are seen on people’s heads, while shoes are most often seen close to the ground. Such positional regularities bias the distribution of objects across the visual field: hats are more often encountered in the upper visual field, while shoes are more often encountered in the lower visual field. Here we tested the hypothesis that typical visual field locations of objects facilitate cortical processing. We recorded functional MRI while participants viewed images of objects that were associated with upper or lower visual field locations. Using multivariate classification, we show that object information can be more successfully decoded from response patterns in object-selective lateral occipital cortex (LO) when the objects are presented in their typical location (e.g., shoe in the lower visual field) than when they are presented in an atypical location (e.g., shoe in the upper visual field). In a functional connectivity analysis, we relate this benefit to increased coupling between LO and early visual cortex, suggesting that typical object positioning facilitates information propagation across the visual hierarchy. Together these results suggest that object representations in occipital visual cortex are tuned to the structure of natural environments. This tuning may support object perception in spatially structured environments. NEW & NOTEWORTHY In the real world, objects appear in predictable spatial locations. Hats, commonly appearing on people’s heads, often fall into the upper visual field. Shoes, mostly appearing on people’s feet, often fall into the lower visual field. Here we used functional MRI to demonstrate that such regularities facilitate cortical processing: Objects encountered in their typical locations are coded more efficiently, which may allow us to effortlessly recognize objects in natural environments.

scholarly journals Resolving the organization of the third tier visual cortex in primates: A hypothesis-based approach

2015 ◽  
Vol 32 ◽  
Author(s):  
ALESSANDRA ANGELUCCI ◽  
MARCELLO G.P. ROSA
Keyword(s):  
Visual Cortex ◽  
Experimental Evidence ◽  
Visual Processing ◽  
New World ◽  
Dorsal Stream ◽  
Macaque Monkey ◽  
New World Monkeys ◽  
New World Primates ◽  
Developmental Context ◽  
The Third

AbstractAs highlighted by several contributions to this special issue, there is still ongoing debate about the number, exact location, and boundaries of the visual areas located in cortex immediately rostral to the second visual area (V2), i.e., the “third tier” visual cortex, in primates. In this review, we provide a historical overview of the main ideas that have led to four models of third tier cortex organization, which are at the center of today's debate. We formulate specific predictions of these models, and compare these predictions with experimental evidence obtained primarily in New World primates. From this analysis, we conclude that only one of these models (the “multiple-areas” model) can accommodate the breadth of available experimental evidence. According to this model, most of the third tier cortex in New World primates is occupied by two distinct areas, both representing the full contralateral visual quadrant: the dorsomedial area (DM), restricted to the dorsal half of the third visual complex, and the ventrolateral posterior area (VLP), occupying its ventral half and a substantial fraction of its dorsal half. DM belongs to the dorsal stream of visual processing, and overlaps with macaque parietooccipital (PO) area (or V6), whereas VLP belongs to the ventral stream and overlaps considerably with area V3 proposed by others. In contrast, there is substantial evidence that is inconsistent with the concept of a single elongated area V3 lining much of V2. We also review the experimental evidence from macaque monkey and humans, and propose that, once the data are interpreted within an evolutionary-developmental context, these species share a homologous (but not necessarily identical) organization of the third tier cortex as that observed in New World monkeys. Finally, we identify outstanding issues, and propose experiments to resolve them, highlighting in particular the need for more extensive, hypothesis-driven investigations in macaque and humans.

Topographic map reorganization in cat area 17 after early monocular retinal lesions

2002 ◽  
Vol 19 (1) ◽  
pp. 85-96 ◽  
Author(s):  
KAZUKI MATSUURA ◽  
BIN ZHANG ◽  
TAKAFUMI MORI ◽  
EARL L. SMITH ◽  
JON H. KAAS ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Receptive Fields ◽  
Optic Disk ◽  
Area 17 ◽  
Topographic Map ◽  
Retinal Lesions ◽  
The World ◽  
Blind Spots ◽  
Made In

Neither discrete peripheral retinal lesions nor the normal optic disk produces obvious holes in one's percept of the world because the visual brain appears to perceptually “fill in” these blind spots. Where in the visual brain or how this filling in occurs is not well understood. A prevailing hypothesis states that topographic map of visual cortex reorganizes after retinal lesions, which “sews up” the hole in the topographic map representing the deprived area of cortex (cortical scotoma) and may lead to perceptual filling in. Since the map reorganization does not typically occur unless retinotopically matched lesions are made in both eyes, we investigated the conditions in which monocular retinal lesions can induce comparable map reorganization. We found that following monocular retinal lesions, deprived neurons in cat area 17 can acquire new receptive fields if the lesion occurred relatively early in life (8 weeks of age) and the lesioned cats experienced a substantial period of recovery (>3 years). Quantitative determination of the monocular and binocular response properties of reactivated units indicated that responses to the lesioned eye for such neurons were remarkably robust, and that the receptive-field properties for the two eyes were generally similar. Moreover, excitatory or inhibitory binocular interactions were found in the majority of experimental units when the two eyes were activated together. These results are consistent with the hypothesis that map reorganization after monocular retinal lesions require experience-dependent plasticity and may be involved in the perceptual filling in of blind spots due to retinal lesions early in life.

scholarly journals Mouse visual cortex contains a region of enhanced spatial resolution

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Enny H. van Beest ◽  
Sreedeep Mukherjee ◽  
Lisa Kirchberger ◽  
Ulf H. Schnabel ◽  
Chris van der Togt ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Eye Movements ◽  
Visual Processing ◽  
Receptive Fields ◽  
Single Neurons ◽  
Two Photon ◽  
Representation Of Space ◽  
Freely Moving ◽  
Mapping Techniques ◽  
Mouse Visual Cortex

AbstractThe representation of space in mouse visual cortex was thought to be relatively uniform. Here we reveal, using population receptive-field (pRF) mapping techniques, that mouse visual cortex contains a region in which pRFs are considerably smaller. This region, the “focea,” represents a location in space in front of, and slightly above, the mouse. Using two-photon imaging we show that the smaller pRFs are due to lower scatter of receptive-fields at the focea and an over-representation of binocular regions of space. We show that receptive-fields of single-neurons in areas LM and AL are smaller at the focea and that mice have improved visual resolution in this region of space. Furthermore, freely moving mice make compensatory eye-movements to hold this region in front of them. Our results indicate that mice have spatial biases in their visual processing, a finding that has important implications for the use of the mouse model of vision.

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