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Author

Shwe Ei

Other affiliations: King's College London
Bio: Shwe Ei is an academic researcher from University College London. The author has contributed to research in topics: Visual cortex & Population. The author has an hindex of 1, co-authored 3 publications receiving 5 citations. Previous affiliations of Shwe Ei include King's College London.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the heritability of retinotopic maps in human visual cortex using functional magnetic resonance imaging was found to be around 10-20% for polar angle preferences and spatial selectivity in extrastriate areas V2 and V3.

8 citations

Posted ContentDOI
05 May 2020-bioRxiv
TL;DR: Inter-individual differences in perceptual bias for size judgments showed considerable heritability, consistent with heritability of broad, eccentricity-dependent properties of visual function and cortical architecture, while quadrant-specific idiosyncrasies appear to lack a genetic basis.
Abstract: How much of our visual processing, and thus our visual perception, is inherited? Variations in perceptual judgments of the size of visual objects have been found to correlate with idiosyncratic differences in the spatial sensitivity of primary visual cortex. Here we tested their heritability using retinotopic mapping and psychophysical experiments on size perception. The spatial sensitivity of human visual cortex, quantified by population receptive field analysis, was more similar in monozygotic (MZ) than dizygotic (DZ) twin pairs, especially in extrastriate regions, suggesting a partial genetic determination. Furthermore, inter-individual differences in perceptual bias for size judgments – how large or small stimuli appear to an observer – showed considerable heritability. This contrasts with previously reported idiosyncrasies across visual field quadrants, which showed little evidence of heritability. Our findings are therefore consistent with heritability of broad, eccentricity-dependent properties of visual function and cortical architecture, while quadrant-specific idiosyncrasies appear to lack a genetic basis.

2 citations

Posted ContentDOI
06 Dec 2020-bioRxiv
TL;DR: In this article, the heritability of retinotopic maps in human visual cortex using functional magnetic resonance imaging was found to be at least partially genetically determined in monozygotic (MZ) and dizygotic (DZ) twin pairs.
Abstract: How much of the functional organization of our visual system is inherited? Here we tested the heritability of retinotopic maps in human visual cortex using functional magnetic resonance imaging. We demonstrate that retinotopic organization shows a closer correspondence in monozygotic (MZ) compared to dizygotic (DZ) twin pairs, suggesting a partial genetic determination. Using population receptive field (pRF) analysis to examine the preferred spatial location and selectivity of these neuronal populations, we further demonstrate that across cortical regions V1-V3, map architecture was more similar in MZ than DZ twins. The heritability of spatial selectivity, as quantified by pRF size, increased across the visual hierarchy. Our findings are consistent with heritability in both the arrangement of areal boundaries and stimulus tuning properties of visual cortex. This could constitute a neural substrate for variations in a range of perceptual effects, which themselves have been found to be at least partially genetically determined.

Cited by
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01 Apr 2010
TL;DR: The origin and function of the Gennari stripe in the primary visual cortex have been investigated in the presence of visual input as discussed by the authors, and it was shown that it does not degenerate in the absence of visual information.
Abstract: The primary visual cortex V1, when dissected, is characterized by an easily identifiable anatomical landmark: the stria of Gennari or Gennari stripe. However, the origin and function of the Gennari stripe is so far unknown. In order to shed some light on this question, we acquired 7-T magnetic resonance imaging (MRI) brain scans of congenitally blind (CB) people, who have never had visual experience. If the stria of Gennari requires visual input to develop or to maintain its homeostasis, such subjects should lack this structure. If it is reliably detectable in the CB, it must form and persist independently of visual sensation. This question has never previously been explored in living subjects. For the first time, the use of 7-T high-resolution MRI enables such investigations because of the excellent signal-to-noise ratio at this magnetic field strength. For comparison, we scanned sighted subjects using the same experimental parameters. We detected the stria of Gennari reliably in both sighted and blind subjects, showing that this anatomical feature is not a developmental result of visual input, and it does not degenerate in the absence of visual input.

61 citations

Journal ArticleDOI
03 Aug 2021-eLife
TL;DR: In this paper, a fine angular resolution of the human primary visual cortex was measured in 163 subjects, with a pattern similar to behavior, and the radial asymmetries in the cortex are larger than those found in the retina, and they are correlated between monozygotic twin pairs.
Abstract: 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 the human primary visual cortex, measured in 163 subjects, varies substantially around the visual field, with a pattern similar to behavior. These radial asymmetries in the 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.

42 citations

Journal ArticleDOI
TL;DR: In this paper , the authors quantified individual differences in the best understood functionally defined regions of cortex: V1, V2, V3, and V4 using the Human Connectome Project 7T Retinotopy Dataset.
Abstract: How variable is the functionally defined structure of early visual areas in human cortex and how much variability is shared between twins? Here we quantify individual differences in the best understood functionally defined regions of cortex: V1, V2, V3. The Human Connectome Project 7T Retinotopy Dataset includes retinotopic measurements from 181 subjects (109 female, 72 male), including many twins. We trained four "anatomists" to manually define V1-V3 using retinotopic features. These definitions were more accurate than automated anatomical templates and showed that surface areas for these maps varied more than threefold across individuals. This threefold variation was little changed when normalizing visual area size by the surface area of the entire cerebral cortex. In addition to varying in size, we find that visual areas vary in how they sample the visual field. Specifically, the cortical magnification function differed substantially among individuals, with the relative amount of cortex devoted to central vision varying by more than a factor of 2. To complement the variability analysis, we examined the similarity of visual area size and structure across twins. Whereas the twin sample sizes are too small to make precise heritability estimates (50 monozygotic pairs, 34 dizygotic pairs), they nonetheless reveal high correlations, consistent with strong effects of the combination of shared genes and environment on visual area size. Collectively, these results provide the most comprehensive account of individual variability in visual area structure to date, and provide a robust population benchmark against which new individuals and developmental and clinical populations can be compared.SIGNIFICANCE STATEMENT Areas V1, V2, and V3 are among the best studied functionally defined regions in human cortex. Using the largest retinotopy dataset to date, we characterized the variability of these regions across individuals and the similarity between twin pairs. We find that the size of visual areas varies dramatically (up to 3.5×) across healthy young adults, far more than the variability of the cerebral cortex size as a whole. Much of this variability appears to arise from inherited factors, as we find very high correlations in visual area size between monozygotic twin pairs, and lower but still substantial correlations between dizygotic twin pairs. These results provide the most comprehensive assessment of how functionally defined visual cortex varies across the population to date.

11 citations

Journal ArticleDOI
TL;DR: The role of transcription in the functional layout of a single region within the adult brain has yet to be clarified, likely owing to the difficulty of identifying a brain region anatomically consistent enough across individuals with dense enough tissue sampling as mentioned in this paper.
Abstract: Gene expression gradients radiating from regions of primary sensory cortices have recently been described and are thought to underlie the large-scale organization of the human cerebral cortex. However, the role of transcription in the functional layout of a single region within the adult brain has yet to be clarified, likely owing to the difficulty of identifying a brain region anatomically consistent enough across individuals with dense enough tissue sampling. Overcoming these hurdles in human primary visual cortex (V1), we show a relationship between differential gene expression and the cortical layout of eccentricity in human V1. Interestingly, these genes are unique from those previously identified that contribute to the positioning of cortical areas in the visual processing hierarchy. Enrichment analyses show that a subset of the identified genes encode for structures related to inhibitory interneurons, ion channels, as well as cellular projections, and are expressed more in foveal compared to peripheral portions of human V1. These findings predict that tissue density should be higher in foveal compared to peripheral V1. Using a histological pipeline, we validate this prediction using Nissl-stained sections of postmortem occipital cortex. We discuss these findings relative to previous studies in non-human primates, as well as in the context of an organizational pattern in which the adult human brain employs transcription gradients at multiple spatial scales: across the cerebral cortex, across areas within processing hierarchies, and within single cortical areas.

6 citations

Journal ArticleDOI
TL;DR: In this article , the authors investigated whether visual cortex reorganization in congenital blindness results in connectivity patterns that are particularly variable across individuals, focusing on resting-state functional connectivity (RSFC) patterns from the primary visual cortex.
Abstract: Visual cortex organization is highly consistent across individuals. But to what degree does this consistency depend on life experience, in particular sensory experience? In this study, we asked whether visual cortex reorganization in congenital blindness results in connectivity patterns that are particularly variable across individuals, focusing on resting-state functional connectivity (RSFC) patterns from the primary visual cortex. We show that the absence of shared visual experience results in more variable RSFC patterns across blind individuals than sighted controls. Increased variability is specifically found in areas that show a group difference between the blind and sighted in their RSFC. These findings reveal a relationship between brain plasticity and individual variability; reorganization manifests variably across individuals. We further investigated the different patterns of reorganization in the blind, showing that the connectivity to frontal regions, proposed to have a role in the reorganization of the visual cortex of the blind toward higher cognitive roles, is highly variable. Further, we link some of the variability in visual-to-frontal connectivity to another environmental factor-duration of formal education. Together, these findings show a role of postnatal sensory and socioeconomic experience in imposing consistency on brain organization. By revealing the idiosyncratic nature of neural reorganization, these findings highlight the importance of considering individual differences in fitting sensory aids and restoration approaches for vision loss.SIGNIFICANCE STATEMENT The typical visual system is highly consistent across individuals. What are the origins of this consistency? Comparing the consistency of visual cortex connectivity between people born blind and sighted people, we showed that blindness results in higher variability, suggesting a key impact of postnatal individual experience on brain organization. Further, connectivity patterns that changed following blindness were particularly variable, resulting in diverse patterns of brain reorganization. Individual differences in reorganization were also directly affected by nonvisual experiences in the blind (years of formal education). Together, these findings show a role of sensory and socioeconomic experiences in creating individual differences in brain organization and endorse the use of individual profiles for rehabilitation and restoration of vision loss.

5 citations