Linking individual differences in human V1 to perception around the visual field

Abstract A central question in neuroscience is how the organization of cortical maps relates to perception, for which human primary visual cortex (V1) is an ideal model system. V1 nonuniformly samples the retinal image, with greater cortical magnification (surface area per degree of visual field) at the fovea than periphery, and at the horizontal than vertical meridian. Moreover, the size and organization of V1 differs greatly across individuals. Here, we used fMRI and psychophysics in the same individuals to quantify individual differences in V1 cortical magnification and perceptual contrast sensitivity at the four polar angle meridians. Across individuals, the overall size of V1 and localized cortical magnification both positively correlated with contrast sensitivity. Moreover, increases in cortical magnification and contrast sensitivity at the horizontal compared to the vertical meridian were strongly correlated. These data reveal a tight link between cortical anatomy and visual perception at the level of individual observer and stimulus location.

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Cortical Magnification in Human Visual Cortex Parallels Task Performance around the Visual Field

eLife ◽

10.7554/elife.67685 ◽

2021 ◽

Vol 10 ◽

Author(s):

Noah C Benson ◽

Eline R Kupers ◽

Antoine Babot ◽

Marisa Carrasco ◽

Jonathan Winawer

Keyword(s):

Visual Cortex ◽

Visual Field ◽

Polar Angle ◽

Monozygotic Twin ◽

Human Vision ◽

Retinal Cell ◽

Vertical Meridian ◽

Cortical Magnification ◽

Cell Densities ◽

And Behavior

Human vision has striking radial asymmetries, with performance on many tasks varying sharply with stimulus polar angle. Performance is generally better on the horizontal than vertical meridian, and on the lower than upper vertical meridian, and these asymmetries decrease gradually with deviation from the vertical meridian. Here we report cortical magnification at a fine angular resolution around the visual field. This precision enables comparisons between cortical magnification and behavior, between cortical magnification and retinal cell densities, and between cortical magnification in twin pairs. We show that cortical magnification in human primary visual cortex, measured in 163 subjects, varies substantially around the visual field, with a pattern similar to behavior. These radial asymmetries in cortex are larger than those found in the retina, and they are correlated between monozygotic twin pairs. These findings indicate a tight link between cortical topography and behavior, and suggest that visual field asymmetries are partly heritable.

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Cortical Magnification in Human Visual Cortex Parallels Task Performance around the Visual Field

10.1101/2020.08.26.268383 ◽

2020 ◽

Cited By ~ 1

Author(s):

Noah C. Benson ◽

Eline R. Kupers ◽

Antoine Barbot ◽

Marisa Carrasco ◽

Jonathan Winawer

Keyword(s):

Visual Cortex ◽

Visual Field ◽

Polar Angle ◽

Monozygotic Twin ◽

Human Vision ◽

Retinal Cell ◽

Vertical Meridian ◽

Cortical Magnification ◽

Cell Densities ◽

And Behavior

AbstractHuman vision has striking radial asymmetries, with performance on many tasks varying sharply with stimulus polar angle. Performance is better on the horizontal than vertical meridian, and on the lower than upper vertical meridian, and these asymmetries decrease gradually with deviation from the vertical meridian. Here we report cortical magnification at a fine angular resolution around the visual field. This precision enables comparisons between cortical magnification and behavior, between cortical magnification and retinal cell densities, and between cortical magnification in twin pairs. We show that cortical magnification in human primary visual cortex, measured in 181 subjects, varies around the visual field, with a pattern similar to behavior. We find that these cortical asymmetries are larger than those found in the retina, and that they are correlated between monozygotic twin pairs. These novel findings indicate a tight link between cortical topography and behavior, and suggest that visual field asymmetries are, at least in part, heritable.

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Linking contrast sensitivity to cortical magnification in human primary visual cortex

10.1101/2021.10.04.463138 ◽

2021 ◽

Author(s):

Marc M. Himmelberg ◽

Jonathan Winawer ◽

Marisa Carrasco

Keyword(s):

Visual Cortex ◽

Visual Perception ◽

Contrast Sensitivity ◽

Surface Area ◽

Primary Visual Cortex ◽

Fundamental Property ◽

Polar Angle ◽

Strongly Correlated ◽

V1 Neurons ◽

Cortical Magnification

ABSTRACTThe size and organization of primary visual cortex (V1) varies across individuals. Across neurotypical adults, V1 size varies more than twofold. Within individuals, surface area per unit of visual field – cortical magnification – varies with eccentricity and polar angle. Contrast sensitivity and cortical magnification covary with eccentricity, therefore it has been hypothesized that cortical magnification, specifically the number of activated V1 neurons, limits contrast sensitivity. Here, we quantify the relation between contrast sensitivity and V1 cortical magnification across observers and polar angle. We measured contrast sensitivity at four cardinal meridians in 29 observers. We then used fMRI to measure the size of V1 in the same observers, and the amount of surface area representing each of the four meridians (wedge-ROIs within 15° polar angle of the meridians, 1 to 8° eccentricity). We found that: First, an observer’s contrast sensitivity (averaged across polar angles) was predicted by the size of V1. Second, contrast sensitivity at each cardinal meridian was correlated with the surface area of the wedge-ROIs centered at the corresponding meridian. Third, increases in contrast sensitivity and cortical magnification at the horizontal compared to vertical meridian (horizontal-vertical anisotropy, ‘HVA’) were strongly correlated: a larger HVA in contrast sensitivity corresponded to a larger HVA in cortical magnification. These results reveal that contrast sensitivity and cortical magnification co-vary across observers and demonstrate a link between perceptual polar angle asymmetries and cortical anatomy. Broadly, the results show a link between visual perception and the idiosyncratic cortical organization of V1 in neurotypical observers.SIGNIFICANCE STATEMENTContrast sensitivity is a fundamental property of the human visual system, which indexes the limits of what one can detect or discriminate – the window of visibility. Contrast sensitivity varies with stimulus location on the retina and across observers. These variations are not well understood. Using psychophysics and magnetic resonance imaging, we tested the hypothesis that contrast sensitivity depends on the amount of responsive tissue in primary visual cortex (V1). Individuals with greater contrast sensitivity had a larger V1. Further, within observers, variation in contrast sensitivity across polar angle locations matched the variation in V1 surface area representing those locations. These findings demonstrate a tight link between visual perception and cortical anatomy, both within and among people.

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Asymmetries in visual acuity around the visual field

10.31234/osf.io/ruwp9 ◽

2020 ◽

Cited By ~ 2

Author(s):

Antoine Barbot ◽

Shutian Xue ◽

Marisa Carrasco

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Psychometric Function ◽

Spatial Resolution ◽

Visual Processing ◽

Polar Angle ◽

Angular Distance ◽

Human Vision ◽

Gradual Change ◽

Vertical Meridian

Human vision is heterogeneous around the visual field. At a fixed eccentricity, performance is better along the horizontal than the vertical meridian, and along the lower than the upper vertical meridian. These asymmetric patterns, termed performance fields, have been found in numerous visual tasks, including those mediated by contrast sensitivity and spatial resolution. However, it is unknown whether spatial resolution asymmetries are confined to the cardinal meridians or whether, and how far, they extend into the upper and lower hemifields. Here, we measured visual acuity at isoeccentric peripheral locations (10 deg eccentricity), every 15º of polar angle. On each trial, observers judged the orientation (±45º) of one out of four equidistant, suprathreshold grating stimuli varying in spatial frequency (SF). On each block, we measured performance as a function of stimulus SF at 4 out of 24 isoeccentric locations. We estimated the 75%-correct SF threshold, SF cutoff point (i.e., chance-level) and slope of the psychometric function for each location. We found higher SF estimates –i.e., better acuity– for the horizontal than the vertical meridian, and for the lower than the upper vertical meridian. These asymmetries were most pronounced at the cardinal meridians and decreased gradually as the angular distance from the vertical meridian increased. This gradual change in acuity with polar angle reflected a shift of the psychometric function without changes in slope. The same pattern was found under binocular and monocular viewing conditions. These findings advance our understanding of visual processing around the visual field and help constrain models of visual perception.

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Identification of the ventral occipital visual field maps in the human brain

10.1101/035980 ◽

2016 ◽

Author(s):

Jonathan Winawer ◽

Nathan Witthoft

Keyword(s):

Visual Field ◽

Human Brain ◽

Human Subjects ◽

Polar Angle ◽

Vertical Meridian ◽

Retinotopic Mapping ◽

Collateral Sulcus ◽

Anatomical Images ◽

Visual Field Maps ◽

Magnetic Resonance Imaging Mri

The location and topography of the first three visual field maps in the human brain, V1-V3, are well agreed upon and routinely measured across most laboratories. The position of 4th visual field map, "hV4", is identified with less consistency in the neuroimaging literature. Using magnetic resonance imaging (MRI) data, we describe landmarks to help identify the position and borders of hV4. The data consist of anatomical images, visualized as cortical meshes to highlight the sulcal and gyral patterns, and functional data obtained from retinotopic mapping experiments, visualized as eccentricity and angle maps on the cortical surface. Several features of the functional and anatomical data can be found across nearly all subjects and are helpful for identifying the location and extent of the hV4 map. The medial border of hV4 is shared with the posterior, ventral portion of V3, and is marked by a retinotopic representation of the upper vertical meridian. The anterior border of hV4 is shared with the VO-1 map, and falls on a retinotopic representation of the peripheral visual field, usually coincident with the posterior transverse collateral sulcus. The ventro-lateral edge of the map typically falls on the inferior occipital gyrus, where functional MRI artifacts often obscure the retinotopic data. Finally, we demonstrate the continuity of retinotopic parameters between hV4 and its neighbors; hV4 and V3v contain iso-eccentricity lines in register, whereas hV4 and VO-1 contain iso-polar angle lines in register. Together, the multiple constraints allow for a consistent identification of the hV4 map across most human subjects.

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Cross-dataset reproducibility of population receptive field (pRF) estimates and cortical magnification asymmetries

10.1101/2021.04.12.439348 ◽

2021 ◽

Author(s):

Marc M. Himmelberg ◽

Jan W. Kurzawski ◽

Noah C. Benson ◽

Denis G. Pelli ◽

Marisa Carrasco ◽

...

Keyword(s):

Visual Field ◽

Receptive Field ◽

Large Scale ◽

Receptive Fields ◽

Polar Angle ◽

New York University ◽

Retinotopic Maps ◽

Human Connectome Project ◽

Cortical Magnification ◽

Size Estimates

AbstractPopulation receptive field (pRF) models fit to fMRI data are used to non-invasively measure retinotopic maps in human visual cortex, and these maps are a fundamental component of visual neuroscience experiments. We examined the reproducibility of retinotopic maps across two datasets: a newly acquired retinotopy dataset from New York University (NYU) (n=44) and a public dataset from the Human Connectome Project (HCP) (n=181). Our goal was to assess the degree to which pRF properties are similar across datasets, despite substantial differences in their experimental protocols. The two datasets differ in stimulus design, participant pool, fMRI protocol, MRI field strength, and preprocessing pipelines. We assessed the cross-dataset reproducibility of the two datasets in terms of the similarity of vertex-wise pRF estimates and in terms of large-scale cortical magnification properties. Within V1, V2, V3, and hV4, the group-median NYU and HCP vertex-wise polar angle estimates were nearly identical. Both eccentricity and pRF size estimates were also strongly correlated between the two datasets, but with a slope different from 1; the eccentricity and pRF size estimates were systematically greater in the NYU data. Next, to compare large-scale map properties, we quantified two polar angle asymmetries in V1 cortical magnification previously identified in the HCP data. The prior work reported more cortical surface area representing the horizontal than vertical visual field meridian, and the lower than upper vertical visual field meridian. We confirm both of these results in the NYU dataset. Together, our findings show that the retinotopic properties of V1-hV4 can be reliably measured between two datasets, despite numerous differences in their experimental design. fMRI-derived retinotopic maps are reproducible because they rely on an explicit computational model that is grounded in physiological evidence of how visual receptive fields are organized, allowing one to quantitatively characterize the BOLD signal in terms of stimulus properties (i.e., location and size). The new NYU Retinotopy Dataset will serve as a useful benchmark for testing hypotheses about the organization of visual areas and for comparison to the HCP Retinotopy Dataset.

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Identification of the ventral occipital visual field maps in the human brain

F1000Research ◽

10.12688/f1000research.12364.1 ◽

2017 ◽

Vol 6 ◽

pp. 1526 ◽

Cited By ~ 5

Author(s):

Jonathan Winawer ◽

Nathan Witthoft

Keyword(s):

Visual Field ◽

Human Brain ◽

Human Subjects ◽

Polar Angle ◽

Imaging Data ◽

Vertical Meridian ◽

Retinotopic Mapping ◽

Collateral Sulcus ◽

Anatomical Images ◽

Visual Field Maps

The location and topography of the first three visual field maps in the human brain, V1-V3, are well agreed upon and routinely measured across most laboratories. The position of 4th visual field map, ‘hV4’, is identified with less consistency in the neuroimaging literature. Using magnetic resonance imaging data, we describe landmarks to help identify the position and borders of ‘hV4’. The data consist of anatomical images, visualized as cortical meshes to highlight the sulcal and gyral patterns, and functional data obtained from retinotopic mapping experiments, visualized as eccentricity and angle maps on the cortical surface. Several features of the functional and anatomical data can be found across nearly all subjects and are helpful for identifying the location and extent of the hV4 map. The medial border of hV4 is shared with the posterior, ventral portion of V3, and is marked by a retinotopic representation of the upper vertical meridian. The anterior border of hV4 is shared with the VO-1 map, and falls on a retinotopic representation of the peripheral visual field, usually coincident with the posterior transverse collateral sulcus. The ventro-lateral edge of the map typically falls on the inferior occipital gyrus, where functional MRI artifacts often obscure the retinotopic data. Finally, we demonstrate the continuity of retinotopic parameters between hV4 and its neighbors; hV4 and V3v contain iso-eccentricity lines in register, whereas hV4 and VO-1 contain iso-polar angle lines in register. Together, the multiple constraints allow for a consistent identification of the hV4 map across most human subjects.

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Imaging Bioactivated Hepatic Spheroids, An Ideal Model System for Drug Hepatotoxicity Evaluations

HPB ◽

10.1016/j.hpb.2020.11.531 ◽

2021 ◽

Vol 23 ◽

pp. S212

Author(s):

Y. Wang ◽

J. Liu ◽

R. Li

Keyword(s):

Model System ◽

Ideal Model ◽

Ideal Model System

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Association of ocular blood flow and contrast sensitivity in normal tension glaucoma

Graefe s Archive for Clinical and Experimental Ophthalmology ◽

10.1007/s00417-021-05235-8 ◽

2021 ◽

Author(s):

David Kuerten ◽

Matthias Fuest ◽

Peter Walter ◽

Babac Mazinani ◽

Niklas Plange

Keyword(s):

Blood Flow ◽

Visual Field ◽

Contrast Sensitivity ◽

Visual Field Defect ◽

Prospective Trial ◽

Normal Tension Glaucoma ◽

Ocular Blood Flow ◽

Retinal Blood Flow ◽

Control Group ◽

Field Defect

Abstract Purpose To investigate the relationship of ocular blood flow (via arteriovenous passage time, AVP) and contrast sensitivity (CS) in healthy as well as normal tension glaucoma (NTG) subjects. Design Mono-center comparative prospective trial Methods Twenty-five NTG patients without medication and 25 healthy test participants were recruited. AVP as a measure of retinal blood flow was recorded via fluorescein angiography after CS measurement using digital image analysis. Association of AVP and CS at 4 spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) was explored with correlation analysis. Results Significant differences regarding AVP, visual field defect, intraocular pressure, and CS measurement were recorded in-between the control group and NTG patients. In NTG patients, AVP was significantly correlated to CS at all investigated cpd (3 cpd: r = − 0.432, p< 0.03; 6 cpd: r = − 0.629, p< 0.0005; 12 cpd: r = − 0.535, p< 0.005; and 18 cpd: r = − 0.58, p< 0.001), whereas no significant correlations were found in the control group. Visual acuity was significantly correlated to CS at 6, 12, and 18 cpd in NTG patients (r = − 0.68, p< 0.002; r = − 0.54, p< .02, and r = − 0.88, p< 0.0001 respectively), however not in healthy control patients. Age, visual field defect MD, and PSD were not significantly correlated to CS in in the NTG group. MD and PSD were significantly correlated to CS at 3 cpd in healthy eyes (r = 0.55, p< 0.02; r = − 0.47, p< 0.03). Conclusion Retinal blood flow alterations show a relationship with contrast sensitivity loss in NTG patients. This might reflect a disease-related link between retinal blood flow and visual function. This association was not recorded in healthy volunteers.

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