Disparity-Selective Neurons in Area V4 of Macaque Monkeys

2002 ◽  
Vol 87 (4) ◽  
pp. 1960-1973 ◽  
Author(s):  
Masayuki Watanabe ◽  
Hiroki Tanaka ◽  
Takanori Uka ◽  
Ichiro Fujita
Keyword(s):  
Receptive Field ◽  
Binocular Disparity ◽  
Temporal Cortex ◽  
Intermediate Stage ◽  
Visual Pathway ◽  
Inferior Temporal Cortex ◽  
Tuning Curves ◽  
Area V4 ◽  
Ventral Visual Pathway ◽  
V4 Neurons

Area V4 is an intermediate stage of the ventral visual pathway providing major input to the final stages in the inferior temporal cortex (IT). This pathway is involved in the processing of shape, color, and texture. IT neurons are also sensitive to horizontal binocular disparity, suggesting that binocular disparity is processed along the ventral visual pathway. In the present study, we examined the processing of binocular disparity information by V4 neurons. We recorded responses of V4 neurons to binocularly disparate stimuli. A population of V4 neurons modified their responses according to changes of stimulus disparity; neither monocular responses nor eye movements could account for this modulation. Disparity-tuning curves were similar for different locations within a neuron's receptive field. Neighboring neurons recorded using a single electrode displayed similar disparity-tuning properties. These findings indicate that a population of V4 neurons is selective for binocular disparity, invariant for the position of the stimulus within the receptive field. The finding that V4 neurons with similar disparity selectivity are clustered suggests the existence of functional modules for disparity processing in V4.

scholarly journals Pooled, but not single-neuron, responses in macaque V4 represent a solution to the stereo correspondence problem

2016 ◽  
Vol 115 (4) ◽  
pp. 1917-1931 ◽  
Author(s):  
Mohammad Abdolrahmani (ﻣﺤﻤﺪ ﻋﺒﺪاﻟﺮﺣﻤﻨﯽ) ◽  
Takahiro Doi (土井隆弘) ◽  
Hiroshi M. Shiozaki (塩崎博史) ◽  
Ichiro Fujita (藤田一郎)
Keyword(s):  
Single Neuron ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Correspondence Problem ◽  
Tuning Curves ◽  
Area V4 ◽  
Random Dot Stereograms ◽  
Left And Right ◽  
V4 Neurons ◽  
Psychophysical Studies

Binocular disparity is an important cue for depth perception. To correctly represent disparity, neurons must find corresponding visual features between the left- and right-eye images. The visual pathway ascending from V1 to inferior temporal cortex solves the correspondence problem. An intermediate area, V4, has been proposed to be a critical stage in the correspondence process. However, the distinction between V1 and V4 is unclear, because accumulating evidence suggests that the process begins within V1. In this article, we report that the pooled responses in macaque V4, but not responses of individual neurons, represent a solution to the correspondence problem. We recorded single-unit responses of V4 neurons to random-dot stereograms of varying degrees of anticorrelation. To achieve gradual anticorrelation, we reversed the contrast of an increasing proportion of dots as in our previous psychophysical studies, which predicted that the neural correlates of the solution to correspondence problem should gradually eliminate their disparity modulation as the level of anticorrelation increases. Inconsistent with this prediction, the tuning amplitudes of individual V4 neurons quickly decreased to a nonzero baseline with small anticorrelation. By contrast, the shapes of individual tuning curves changed more gradually so that the amplitude of population-pooled responses gradually decreased toward zero over the entire range of graded anticorrelation. We explain these results by combining multiple energy-model subunits. From a comparison with the population-pooled responses in V1, we suggest that disparity representation in V4 is distinctly advanced from that in V1. Population readout of V4 responses provides disparity information consistent with the correspondence solution.

scholarly journals Clustered functional domains for curves and corners in cortical area V4

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Rundong Jiang ◽  
Ian Max Andolina ◽  
Ming Li ◽  
Shiming Tang
Keyword(s):  
Intermediate Stage ◽  
Visual Pathway ◽  
Structural Motif ◽  
Functional Domains ◽  
Complex Object ◽  
Area V4 ◽  
Ventral Visual Pathway ◽  
Ventral Pathway ◽  
Resolution Imaging ◽  
V4 Neurons

The ventral visual pathway is crucially involved in integrating low-level visual features into complex representations for objects and scenes. At an intermediate stage of the ventral visual pathway, V4 plays a crucial role in supporting this transformation. Many V4 neurons are selective for shape segments like curves and corners, however it remains unclear whether these neurons are organized into clustered functional domains, a structural motif common across other visual cortices. Using two-photon calcium imaging in awake macaques, we confirmed and localized cortical domains selective for curves or corners in V4. Single-cell resolution imaging confirmed that curve or corner selective neurons were spatially clustered into such domains. When tested with hexagonal-segment stimuli, we find that stimulus smoothness is the cardinal difference between curve and corner selectivity in V4. Combining cortical population responses with single neuron analysis, our results reveal that curves and corners are encoded by neurons clustered into functional domains in V4. This functionally-specific population architecture bridges the gap between the early and late cortices of the ventral pathway and may serve to facilitate complex object recognition.

scholarly journals Clustered Functional Domains for Curves and Corners in Cortical Area V4

2019 ◽  
Author(s):  
Rundong Jiang ◽  
Ian M. Andolina ◽  
Ming Li ◽  
Shiming Tang
Keyword(s):  
Intermediate Stage ◽  
Visual Pathway ◽  
Structural Motif ◽  
Functional Domains ◽  
Complex Object ◽  
Area V4 ◽  
Ventral Visual Pathway ◽  
Ventral Pathway ◽  
Resolution Imaging ◽  
V4 Neurons

AbstractThe ventral visual pathway is crucially involved in integrating low-level visual features into complex representations for objects and scenes. At an intermediate stage of the ventral visual pathway, V4 plays a crucial role in supporting this transformation. Many V4 neurons are selective for shape segments like curves and corners, however it remains unclear whether these neurons are organized into clustered functional domains, a structural motif common across other visual cortices. Using two-photon calcium imaging in awake macaques, we confirmed and localized cortical domains selective for curves or corners in V4. Single-cell resolution imaging confirmed that curve or corner selective neurons were spatially clustered into such domains. When tested with hexagonal-segment stimuli, we find that stimulus smoothness is the cardinal difference between curve and corner selectivity in V4. Combining cortical population responses with single neuron analysis, our results reveal that curves and corners are encoded by neurons clustered into functional domains in V4. This functionally-specific population architecture bridges the gap between the early and late cortices of the ventral pathway and may serve to facilitate complex object recognition.

Visual properties of neurons in area V4 of the macaque: sensitivity to stimulus form

1987 ◽  
Vol 57 (3) ◽  
pp. 835-868 ◽  
Author(s):  
R. Desimone ◽  
S. J. Schein
Keyword(s):  
Receptive Field ◽  
Temporal Cortex ◽  
Receptive Fields ◽  
Inferior Temporal Cortex ◽  
Field Size ◽  
Lower Visual Field ◽  
Stimulus Form ◽  
Area V4 ◽  
Prestriate Cortex ◽  
Length Width

Area V4, a visuotopically organized area in prestriate cortex of the macaque, is the major source of visual input to the inferior temporal cortex, known to be crucial for object recognition. To examine the selectivity of cells in V4 for stimulus form, we quantitatively measured the responses of 322 cells to bars varying in length, width, orientation, and polarity of contrast, and sinusoidal gratings varying in spatial frequency, phase, orientation, and overall size. All of the cells recorded in V4 were located on the lower portion of the prelunate gyrus. Receptive fields were located almost exclusively within the representation of the central 5 degrees of the lower visual field, and receptive field size, in linear dimension, was 4-7 times greater than that in the corresponding representation of striate cortex (V1). Nearly all receptive fields consisted of overlapping dark and light zones, like “classic” complex fields in V1, but the relative strengths of the dark and light zones often differed. A few cells responded exclusively to light or dark stimuli. Many cells in V4 were selective for stimulus orientation, and a few were selective for direction of motion as well. Although the median orientation bandwidth of the orientation-selective cells (52 degrees) was wider than that reported for oriented cells in V1, approximately 8% of the oriented cells had bandwidths of less than 30 degrees, which is nearly as narrow as the most narrowly tuned cells in V1. The proportion of cells selective for direction of motion (13%) was not markedly different from that reported in V1. The large majority of V4 cells were tuned to the length and width of bars, and the “shape” of the optimal bar varied from cell to cell, as has been reported for cells in the dorsolateral visual area (DL) of the owl monkey, a possible homologue of V4 in the macaque. Preferred lengths and widths varied independently from approximately 0.05 to 6 degrees, with the smallest preferred bars about the size of the smallest receptive fields in V1 and the largest preferred bars larger than any fields in V1. The relationship between the size of the optimal bar and the size of the receptive field varied from cell to cell. Some cells, for example, responded best to bars much narrower or shorter than the field, whereas other cells responded best to bars that filled (but did not extend beyond) the excitatory field in the length, width, or both dimensions.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals A step toward understanding the human ventral visual pathway

2017 ◽  
Vol 117 (3) ◽  
pp. 872-875 ◽  
Author(s):  
Erin Goddard
Keyword(s):  
Temporal Cortex ◽  
Visual Pathway ◽  
Higher Order ◽  
Inferior Temporal Cortex ◽  
Cortical Region ◽  
Functional Responses ◽  
Form Processing ◽  
Ventral Visual Pathway ◽  
New Evidence ◽  
Organizational Principles

The human ventral visual pathway is implicated in higher order form processing, but the organizational principles within this region are not yet well understood. Recently, Lafer-Sousa, Conway, and Kanwisher ( J Neurosci 36: 1682–1697, 2016) used functional magnetic resonance imaging to demonstrate that functional responses in the human ventral visual pathway share a broad homology with the those in macaque inferior temporal cortex, providing new evidence supporting the validity of the macaque as a model of the human visual system in this region. In addition, these results give new clues for understanding the organizational principles within the ventral visual pathway and the processing of higher order color and form, suggesting new avenues for research into this cortical region.

Quantitative Characterization of Disparity Tuning in Ventral Pathway Area V4

2005 ◽  
Vol 94 (4) ◽  
pp. 2726-2737 ◽  
Author(s):  
David A. Hinkle ◽  
Charles E. Connor
Keyword(s):  
Binocular Disparity ◽  
Orientation Tuning ◽  
Quantitative Characterization ◽  
Object Processing ◽  
Gaussian Functions ◽  
Area V4 ◽  
Ventral Pathway ◽  
Object Parts ◽  
V4 Neurons

We performed a quantitative characterization of binocular disparity-tuning functions in the ventral (object-processing) pathway of the macaque visual cortex. We measured responses of 452 area V4 neurons to stimuli with disparities ranging from −1.0 to +1.0°. Asymmetric Gaussian functions fit the raw data best (median R = 0.90), capturing both the modal components (local peaks in the −1.0 to +1.0° range) and the monotonic components (linear or sigmoidal dependency on disparity) of the tuning patterns. Values derived from the asymmetric Gaussian fits were used to characterize neurons on a modal × monotonic tuning domain. Points along the modal tuning axis correspond to classic tuned excitatory and inhibitory patterns; points along the monotonic axis correspond to classic near and far patterns. The distribution on this domain was continuous, with the majority of neurons exhibiting a mixed modal/monotonic tuning pattern. The distribution in the modal dimension was shifted toward excitatory patterns, consistent with previous results in other areas. The distribution in the monotonic dimension was shifted toward tuning for crossed disparities (corresponding to stimuli nearer than the fixation plane). This could reflect a perceptual emphasis on objects or object parts closer to the observer. We also found that disparity-tuning strength was positively correlated with orientation-tuning strength and color-tuning strength, and negatively correlated with receptive field eccentricity.

scholarly journals Stimulus Dependence of Disparity Coding in Primate Visual Area V4

2005 ◽  
Vol 93 (1) ◽  
pp. 620-626 ◽  
Author(s):  
Jay Hegdé ◽  
David C. Van Essen
Keyword(s):  
Binocular Disparity ◽  
Three Dimensional ◽  
Visual Area ◽  
Tuning Curves ◽  
Depth Cues ◽  
Area V4 ◽  
Random Dot Stereograms ◽  
Dimensional Shape ◽  
Visual Area V4 ◽  
Three Dimensional Shape

Disparity tuning in visual cortex has been shown using a variety of stimulus types that contain stereoscopic depth cues. It is not known whether different stimuli yield similar disparity tuning curves. We studied whether cells in visual area V4 of the macaque show similar disparity tuning profiles when the same set of disparity values were tested using bars or dynamic random dot stereograms, which are among the most commonly used stimuli for this purpose. In a majority of V4 cells (61%), the shape of the disparity tuning profile differed significantly for the two stimulus types. The two sets of stimuli yielded statistically indistinguishable disparity tuning profiles for only a small minority (6%) of V4 cells. These results indicate that disparity tuning in V4 is stimulus-dependent. Given the fact that bar stimuli contain two-dimensional (2-D) shape cues, and the random dot stereograms do not, our results also indicate that V4 cells represent 2-D shape and binocular disparity in an interdependent fashion, revealing an unexpected complexity in the analysis of depth and three-dimensional shape.

scholarly journals Receptive field focus of visual area V4 neurons determines responses to illusory surfaces

2013 ◽  
Vol 110 (42) ◽  
pp. 17095-17100 ◽  
Author(s):  
M. A. Cox ◽  
M. C. Schmid ◽  
A. J. Peters ◽  
R. C. Saunders ◽  
D. A. Leopold ◽  
...  
Keyword(s):  
Receptive Field ◽  
Visual Area ◽  
Area V4 ◽  
Visual Area V4 ◽  
V4 Neurons

Focal attention produces spatially selective processing in visual cortical areas V1, V2, and V4 in the presence of competing stimuli

1993 ◽  
Vol 70 (3) ◽  
pp. 909-919 ◽  
Author(s):  
B. C. Motter
Keyword(s):  
Receptive Field ◽  
Stimulus Presentation ◽  
Spatial Location ◽  
Differential Sensitivity ◽  
Orientation Tuning ◽  
Area V4 ◽  
Focal Attention ◽  
V4 Neurons ◽  
Visual Cortical ◽  
Competing Stimuli

1. The activity of single neurons was recorded in Macaca mulatta monkeys while they performed tasks requiring them to select a cued stimulus from an array of three to eight stimuli and report the orientation of that stimulus. Stimuli were presented in a circular array centered on the fixation target and scaled to place a single stimulus element within the receptive field of the neuron under study. The timing of the cuing event permitted the directing of visual attention to the spatial location of the correct stimulus before its presentation. 2. The effects of focal attention were examined in cortical visual areas V1, V2, and V4, where a total of 672 neurons were isolated with complete studies obtained for 94 V1, 74 V2, and 74 V4 neurons with receptive-field center eccentricities in the range 1.8-8 degrees. Under certain conditions, directed focal attention results in changes in the response of V1, V2, and V4 neurons to otherwise identical stimuli at spatially specific locations. 3. More than one-third of the neurons in each area displayed differential sensitivity when attention was directed toward versus away from the spatial location of the receptive field just before and during stimulus presentation. Both relative increases and decreases in neural activity were observed in association with attention directed at receptive-field stimuli. 4. The presence of multiple competing stimuli in the visual field was a major factor determining the presence or absence of differential sensitivity. About two-thirds of the neurons that were differentially sensitive to the attending condition in the presence of competing stimuli were not differentially sensitive when single stimuli were presented in control studies. For V1 and V2 neurons the presence of only a few (3-4) competing stimuli was sufficient for a majority of the neurons studied; a majority of the V4 neurons required six to eight stimuli in the array before significant differences between attending conditions occurred. 5. For V1 and V2 neurons the neuronal sensitivity differences between attending conditions were observed primarily at or near the peak of the orientation tuning sensitivity for each neuron; the differences were evident over a broader range of orientations in V4 neurons. 6. In conclusion, neural correlates of focal attentive processes can be observed in visual cortical processing in areas V1 and V2 as well as area V4 under conditions that require stimulus feature analysis and selective spatial processing within a field of competing stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

Receptive field properties of neurons in area V3 of macaque monkey extrastriate cortex

1987 ◽  
Vol 57 (4) ◽  
pp. 889-920 ◽  
Author(s):  
D. J. Felleman ◽  
D. C. Van Essen
Keyword(s):  
Receptive Field ◽  
Binocular Disparity ◽  
Visual Fields ◽  
Direction Selectivity ◽  
Extrastriate Cortex ◽  
Thin Strip ◽  
Stimulus Motion ◽  
Form Analysis ◽  
Tuning Curves ◽  
Receptive Field Properties

Receptive field properties of 147 neurons histologically verified to be located in area V3 were investigated during semichronic recording from paralyzed anesthetized macaque monkeys. Quantitative analyses were made of neuron selectivities for direction, orientation, speed, binocular disparity, and color. The majority of neurons in V3 (76%) were strongly orientation selective; 40% demonstrated strong direction selectivity. Most cells were tuned for stimulus speed and almost half showed optimum responses at 16 degrees/s. The distribution of optimum speeds ranged primarily from 4 to 32 degrees/s. Several cells in V3 displayed multi-peaked orientation- and/or direction-tuning curves. These cells had two or more narrowly tuned peaks that were not co-axial. In some ways, they resemble higher-order hypercomplex cells of cat area 19 and may subserve a higher level of form or motion analysis than is seen at antecedent visual areas. Roughly half (45%) of the cells were selective for binocular disparity. Approximately half of these were tuned excitatory in that they showed weak responses when tested through either eye alone, but showed strong binocular facilitation centered on the fixation plane. The other disparity-selective cells were tuned inhibitory or asymmetric in their responses in front and behind the fixation plane. Contrary to previous reports, approximately 20% of the neurons in V3 were color selective in terms of showing a severalfold greater response to the best monochromatic wavelength compared with the worst. Color-tuning curves of the subset of color selective cells had, on average, a full bandwidth at half maximum response of 80-100 nm. A comparison of the receptive field properties of neurons in V3 to those in other areas of visual cortex suggests that V3, like MT, is well suited for the analysis of several aspects of stimulus motion. V3 may also be involved in some aspects of form analysis, particularly at low contrast levels. Comparison with area VP, a thin strip of cortex anterior to ventral V2, which was previously considered part of V3, indicates that direction selectivity is much more prevalent in V3 than in VP. Conversely, color-selective cells are the majority in VP but a minority in V3. This suggests that visual information is processed differently in the upper and lower visual fields.

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