Connections and visual-field mapping in cat's tectoparabigeminal circuit

1979 ◽  
Vol 42 (6) ◽  
pp. 1656-1668 ◽  
Author(s):  
H. Sherk

1. The aim of these experiments was to analyze the organization of the reciprocal connections between the cat's superior colliculus and parabigeminal nucleus. Both physiological and anatomical techniques were employed. 2. A population of cells in the superficial gray and upper optic layers of the colliculus was labeled retrogradely by horseradish peroxidase injections into the parabigeminal nucleus. No other sources of input to the nucleus were found in the brain stem or diencephalon. 3. A map of the visual field within the parabigeminal nucleus was reconstructed by plotting visual receptive fields at 350 parabigeminal sites with microelectrodes. The map resembled that found in the colliculus, although it was considerably less orderly. The entire contralateral visual field was represented and, in addition, roughly the central 40 degrees of the ipsilateral hemifield was included; futhermore, the expansion of the central visual field was similar to that of the tectal map. 4. The return parabigeminal projections to the caudal parts of the two colliculi, representing the contralateral hemifields, were in register with the tectal visual-field maps. In contrast, the parabigeminal pathways to the anterior segments of the two colliculi, representing part of the ipsilateral visual fields, were not clearly topographic. The projection to this part of the contralateral colliculus showed little order, while that to the ipsilateral colliculus was extremely sparse. 5. A single site in the colliculus can be the target of axons from nonhomologous locations in the two parabigeminal nuclei; so that both parabigeminal inputs are in register with the tectal map.

2013 ◽  
Vol 31 (1) ◽  
pp. 85-98 ◽  
Author(s):  
HSIN-HAO YU ◽  
MARCELLO G.P. ROSA

AbstractAlthough the primary visual cortex (V1) is one of the most extensively studied areas of the primate brain, very little is known about how the far periphery of visual space is represented in this area. We characterized the physiological response properties of V1 neurons in anaesthetized marmoset monkeys, using high-contrast drifting gratings. Comparisons were made between cells with receptive fields located in three regions of V1, defined by eccentricity: central (3–5°), near peripheral (5–15°), and far peripheral (>50°). We found that orientation selectivity of individual cells was similar from the center to the far periphery. Nonetheless, the proportion of orientation-selective neurons was higher in central visual field representation than in the peripheral representations. In addition, there were similar proportions of cells representing all orientations, with the exception of the representation of the far periphery, where we detected a bias favoring near-horizontal orientations. The proportions of direction-selective cells were similar throughout V1. When the center/surround organization of the receptive fields was tested with gratings with varying diameters, we found that the population of neurons that was suppressed by large gratings was smaller in the far periphery, although the strength of suppression in these cells tended to be stronger. In addition, the ratio between the diameters of the excitatory centers and suppressive surrounds was similar across the entire visual field. These results suggest that, superimposed on the broad uniformity of V1, there are subtle physiological differences, which indicate that spatial information is processed differently in the central versus far peripheral visual fields.


1993 ◽  
Vol 10 (1) ◽  
pp. 159-171 ◽  
Author(s):  
Robert Desimone ◽  
Jeffrey Moran ◽  
Stanley J. Schein ◽  
Mortimer Mishkin

AbstractThe classically defined receptive fields of V4 cells are confined almost entirely to the contralateral visual field. However, these receptive fields are often surrounded by large, silent suppressive regions, and stimulating the surrounds can cause a complete suppression of response to a simultaneously presented stimulus within the receptive field. We investigated whether the suppressive surrounds might extend across the midline into the ipsilateral visual field and, if so, whether the surrounds were dependent on the corpus callosum, which has a widespread distribution in V4. We found that the surrounds of more than half of the cells tested in the central visual field representation of V4 crossed into the ipsilateral visual field, with some extending up to at least 16 deg from the vertical meridian. Much of this suppression from the ipsilateral field was mediated by the corpus callosum, as section of the callosum dramatically reduced both the strength and extent of the surrounds. There remained, however, some residual suppression that was not further reduced by addition of an anterior commissure lesion. Because the residual ipsilateral suppression was similar in magnitude and extent to that found following section of the optic tract contralateral to the V4 recording, we concluded that it was retinal in origin. Using the same techniques employed in V4, we also mapped the ipsilateral extent of surrounds in the foveal representation of VI in an intact monkey. Results were very similar to those in V4 following commissural or contralateral tract sections. The findings suggest that V4 is a central site for long-range interactions both within and across the two visual hemifields. Taken with previous work, the results are consistent with the notion that the large suppressive surrounds of V4 neurons contribute to the neural mechanisms of color constancy and figure-ground separation.


2007 ◽  
Vol 17 (4) ◽  
pp. 534-537 ◽  
Author(s):  
A. Perdicchi ◽  
M. Iester ◽  
G. Scuderi ◽  
S. Amodeo ◽  
E.M. Medori ◽  
...  

Purpose To make a visual field retrospective analysis on a group of patients with primary open angle glaucoma (POAG) and to evaluate whether different refractive errors could have different progression of the 30° central sensitivity. Methods A total of 110 patients with POAG (52 men and 58 women) were included in the study. All the patients were divided into four subgroups based on the refractive error. The visual field of all the included patients was assessed by an Octopus 30° central visual field every 6 months, for a total of 837 visual fields examined. The resulting data were analyzed by PERIDATA for Windows 1.7 TREND function. Mean defect (MD) and loss variance (LV) were considered for the analysis. Results At the first examination, 82% of eyes showed a global decrease of differential light sensitivity (MD >2 dB) and in 67% the distribution of the defect was nonhomogeneous (LV >6 dB). The analysis of variance for subgroups showed a more significant decrease of MD in highly myopic patients. A linear regression analysis highlighted a statistically significant change in time of MD in 36% and of LV in 34% of the eyes studied. Highly myopic patients had the highest (p<0.01) percentage of change of MD and LV (46% and 42%, respectively). Among the four subgroups, there was no difference in progression of MD decrease in time. Conclusions These results showed that after 5 years of glaucoma, the visual field was altered in most of the eyes examined (82%) and that in 67% of cases, its defect was nonhomogeneous and worsened with the increase of myopia. The regression linear analysis of visual field changes in time showed a progressive increase of MD and LV in approximately one third of all the eyes examined.


1990 ◽  
Vol 64 (4) ◽  
pp. 1352-1360 ◽  
Author(s):  
M. R. Isley ◽  
D. C. Rogers-Ramachandran ◽  
P. G. Shinkman

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)


i-Perception ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 204166952093840
Author(s):  
Li Zhaoping

Consider a gray field comprising pairs of vertically aligned dots; in each pair, one dot is white the other black. When viewed in a peripheral visual field, these pairs appear horizontally aligned. By the Central-Peripheral Dichotomy, this flip tilt illusion arises because top-down feedback from higher to lower visual cortical areas is too weak or absent in the periphery to veto confounded feedforward signals from the primary visual cortex (V1). The white and black dots in each pair activate, respectively, on and off subfields of V1 neural receptive fields. However, the sub-fields’ orientations, and the preferred orientations, of the most activated neurons are orthogonal to the dot alignment. Hence, V1 reports the flip tilt to higher visual areas. Top-down feedback vetoes such misleading reports, but only in the central visual field.


2001 ◽  
Vol 86 (4) ◽  
pp. 1991-2000 ◽  
Author(s):  
Sean P. Dukelow ◽  
Joseph F. X. DeSouza ◽  
Jody C. Culham ◽  
Albert V. van den Berg ◽  
Ravi S. Menon ◽  
...  

In humans, functional imaging studies have demonstrated a homologue of the macaque motion complex, MT+ [suggested to contain both middle temporal (MT) and medial superior temporal (MST)], in the ascending limb of the inferior temporal sulcus. In the macaque monkey, motion-sensitive areas MT and MST are adjacent in the superior temporal sulcus. Electrophysiological research has demonstrated that while MT receptive fields primarily encode the contralateral visual field, MST dorsal (MSTd) receptive fields extend well into the ipsilateral visual field. Additionally, macaque MST has been shown to receive extraretinal smooth-pursuit eye-movement signals, whereas MT does not. We used functional magnetic resonance imaging (fMRI) and the neural properties that had been observed in monkeys to distinguish putative human areas MT from MST. Optic flow stimuli placed in the full field, or contralateral field only, produced a large cluster of functional activation in our subjects consistent with previous reports of human area MT+. Ipsilateral optic flow stimuli limited to the peripheral retina produced activation only in an anterior subsection of the MT+ complex, likely corresponding to putative MSTd. During visual pursuit of a single target, a large portion of the MT+ complex was activated. However, during nonvisual pursuit, only the anterolateral portion of the MT+ complex was activated. This subsection of the MT+ cluster could correspond to putative MSTl (lateral). In summary, we observed three distinct subregions of the human MT+ complex that were arranged in a manner similar to that seen in the monkey.


2014 ◽  
Vol 27 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Ryota Miyauchi ◽  
Dea-Gee Kang ◽  
Yukio Iwaya ◽  
Yôiti Suzuki

The brain apparently remaps the perceived locations of simultaneous auditory and visual events into a unified audio-visual space to integrate and/or compare multisensory inputs. However, there is little qualitative or quantitative data on how simultaneous auditory and visual events are located in the peripheral visual field (i.e., outside a few degrees of the fovea). We presented a sound burst and a flashing light simultaneously not only in the central visual field but also in the peripheral visual field and measured the relative perceived locations of the sound and flash. The results revealed that the sound and flash were perceptually located at the same location when the sound was presented at a 5° periphery of the flash, even when the participants’ eyes were fixed. Measurements of the unisensory locations of each sound and flash in a pointing task demonstrated that the perceived location of the sound shifted toward the front, while the perceived location of the flash shifted toward the periphery. As a result, the discrepancy between the perceptual location of the sound and the flash was around 4°. This suggests that the brain maps the unisensory locations of auditory and visual events into a unified audio-visual space, enabling it to generate unisensory spatial information about the events.


2017 ◽  
Author(s):  
Jesse Gomez ◽  
Vaidehi Natu ◽  
Brianna Jeska ◽  
Michael Barnett ◽  
Kalanit Grill-Spector

ABSTRACTReceptive fields (RFs) processing information in restricted parts of the visual field are a key property of neurons in the visual system. However, how RFs develop in humans is unknown. Using fMRI and population receptive field (pRF) modeling in children and adults, we determined where and how pRFs develop across the ventral visual stream. We find that pRF properties in visual field maps, V1 through VO1, are adult-like by age 5. However, pRF properties in face- and word-selective regions develop into adulthood, increasing the foveal representation and the visual field coverage for faces in the right hemisphere and words in the left hemisphere. Eye-tracking indicates that pRF changes are related to changing fixation patterns on words and faces across development. These findings suggest a link between viewing behavior of faces and words and the differential development of pRFs across visual cortex, potentially due to competition on foveal coverage.


1990 ◽  
Vol 5 (5) ◽  
pp. 489-495 ◽  
Author(s):  
Douglas R. Wylie ◽  
Barrie J. Frost

AbstractPrevious electrophysiological studies have shown that neurons in the nucleus of the basal optic root (nBOR) of the pigeon respond best to wholefield stimuli moving slowly in a particular direction in the contralateral visual field. In this study, we have found that some nBOR neurons respond to wholefield stimulation of both eyes. These binocular neurons have spatially separate receptive fields in both visual fields. Some binocular neurons prefer the same direction of wholefield motion in both eyes, and thus respond best to wholefield visual motion which would result from translation movements of the bird, either ascent, descent, or forward and backward motion. Other neurons prefer opposite directions of wholefield motion in each eye and therefore respond optimally to wholefield visual motion simulating rotational movements of the bird, either roll or yaw. These binocular neurons may play a crucial part in the locomotor behavior of the pigeon by providing visual information distinguishing translational and rotational movements.


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