Arrangement of Ocular Dominance Columns in Human Visual Cortex

Horton, Jonathan C.; Dagi, Linda R.; McCrane, Edna P.; Monasterio, Francisco M. de

doi:10.1001/archopht.1990.01070090127054

Cited by 120 publications

(80 citation statements)

References 25 publications

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“…Similar to the ODC maps in the monkey (26,33,34) and previous human anatomical (16,35) and functional (19,21) studies, preferences to right vs. left eye stimulation were observed as parallel bands modulating in 2-mm cycles (21). We have also demonstrated that such ODC maps are reproducible over days (21).…”

Section: Resultssupporting

confidence: 86%

High-field fMRI unveils orientation columns in humans

Yacoub

Harel

Uğurbil

2008

Proc. Natl. Acad. Sci. U.S.A.

525

488

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Functional (f)MRI has revolutionized the field of human brain research. fMRI can noninvasively map the spatial architecture of brain function via localized increases in blood flow after sensory or cognitive stimulation. Recent advances in fMRI have led to enhanced sensitivity and spatial accuracy of the measured signals, indicating the possibility of detecting small neuronal ensembles that constitute fundamental computational units in the brain, such as cortical columns. Orientation columns in visual cortex are perhaps the best known example of such a functional organization in the brain. They cannot be discerned via anatomical characteristics, as with ocular dominance columns. Instead, the elucidation of their organization requires functional imaging methods. However, because of insufficient sensitivity, spatial accuracy, and image resolution of the available mapping techniques, thus far, they have not been detected in humans. Here, we demonstrate, by using highfield (7-T) fMRI, the existence and spatial features of orientationselective columns in humans. Striking similarities were found with the known spatial features of these columns in monkeys. In addition, we found that a larger number of orientation columns are devoted to processing orientations around 90°(vertical stimuli with horizontal motion), whereas relatively similar fMRI signal changes were observed across any given active column. With the current proliferation of high-field MRI systems and constant evolution of fMRI techniques, this study heralds the exciting prospect of exploring unmapped and/or unknown columnar level functional organizations in the human brain.blood oxygen level-dependent contrast ͉ cortical map ͉ high resolution ͉ spin echo ͉ 7-tesla H igh-field MRI has pushed the level of detail to which submillimeter functional organizations can be mapped with fMRI because of increases in the signal-to-noise ratio (1) and the spatial accuracy of the functional signals (2). These gains are of critical importance because in the mammalian cortex, small functional cortical units that are repeated several times throughout a cortical area appear to constitute fundamental units of computation (3) that underlie mechanisms operative in brain function. One example of these fundamental units is cortical columns, a cluster of neurons with similar functional preferences spanning from the pial surface to the white matter. To no surprise, since their discovery in the somatosensory cortex (4), cortical columns have been identified across the cortex (5) and investigated in great detail (4, 6-8). In the visual cortex, preference to the right or left eye (ocular dominance), direction of motion, spatial frequency, and orientation have all been characterized (9-15). In humans, the first and, to date, the only example of such functional domains ever to have been identified is ocular dominance columns (ODCs). These were first observed by using anatomical staining techniques in the postmortem human brain of subjects who had lost sight in one eye (16). They were foun...

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Section: Resultssupporting

confidence: 86%

High-field fMRI unveils orientation columns in humans

Yacoub

Harel

Uğurbil

2008

Proc. Natl. Acad. Sci. U.S.A.

525

488

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“…To explore the possible contribution of subcortical structures to number processing in humans, we exploit a psychophysical method that allows us to differentiate between cortical vs. subcortical, monocular visual signals before layer IV of primary visual cortex (50)(51)(52). Before this layer, the monocular signals of the visual system are propagated by separate sets of neurons, but beyond layer IV, signals from each eye are no longer segregated, and, because there are relatively few monocular neurons beyond area V1, activation of extrastriate areas is not eye dependent (52).…”

mentioning

confidence: 99%

Numerosity representation is encoded in human subcortex

Collins

Park

Behrmann

2017

Proc. Natl. Acad. Sci. U.S.A.

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Certain numerical abilities appear to be relatively ubiquitous in the animal kingdom, including the ability to recognize and differentiate relative quantities. This skill is present in human adults and children, as well as in nonhuman primates and, perhaps surprisingly, is also demonstrated by lower species such as mosquitofish and spiders, despite the absence of cortical computation available to primates. This ubiquity of numerical competence suggests that representations that connect to numerical tasks are likely subserved by evolutionarily conserved regions of the nervous system. Here, we test the hypothesis that the evaluation of relative numerical quantities is subserved by lower-order brain structures in humans. Using a monocular/dichoptic paradigm, across four experiments, we show that the discrimination of displays, consisting of both large (5-80) and small (1-4) numbers of dots, is facilitated in the monocular, subcortical portions of the visual system. This is only the case, however, when observers evaluate larger ratios of 3:1 or 4:1, but not smaller ratios, closer to 1:1. This profile of competence matches closely the skill with which newborn infants and other species can discriminate numerical quantity. These findings suggest conservation of ontogenetically and phylogenetically lower-order systems in adults' numerical abilities. The involvement of subcortical structures in representing numerical quantities provokes a reconsideration of current theories of the neural basis of numerical cognition, inasmuch as it bolsters the crossspecies continuity of the biological system for numerical abilities.subcortex | numerical cognition | vision | development | phylogeny

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“…13,19,20,23 Revealing Columnar Architectures in the Human V1 by High Resolution fMRI After initial technical struggles with our 4T system, we were ready to conduct decent high resolution experiments in late 1998. We thought that mapping ODCs in the human V1 would be an excellent first project after Menon's group demonstrated the revelation of ocular dominance using fMRI at a high field (4T) 24 and a report of the partial reconstruction of human ODCs using a postmortem specimen 25 provided an invaluable source for understanding the layout of ODCs in relation to the shape and geometry of the V1. However, completion of the quick project we planned took 3 years.…”

Section: Developing Experimental Procedures For High Resolution Fmrimentioning

confidence: 99%

What We Have Learned about Human Primary Visual Cortex from High Resolution Functional Magnetic Resonance Imaging

Cheng

2016

magn reson med sci

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This article reviews our exploration of structures and functions of the human visual cortex using high resolution (submillimeter) functional magnetic resonance imaging (fMRI). It discusses factors that restrict the spatial resolution of blood oxygenation-level dependent (BOLD) fMRI-the point-spread function of the BOLD signal, limited by both imaging techniques to be used and neurovascular units to be studied, and the signal-tonoise ratio. I offer personal thoughts regarding optimal solutions for dealing with these issues, summarize techniques we have developed over the years for using high resolution fMRI to visualize functional architectures and explore physiological properties in the primary visual cortex of humans, including choices of imaging hardware and pulse sequences, experimental procedures, and stimulation paradigms, and finally offer my personal opinions regarding the future of high resolution fMRI.

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Arrangement of Ocular Dominance Columns in Human Visual Cortex

Cited by 120 publications

References 25 publications

High-field fMRI unveils orientation columns in humans

High-field fMRI unveils orientation columns in humans

Numerosity representation is encoded in human subcortex

What We Have Learned about Human Primary Visual Cortex from High Resolution Functional Magnetic Resonance Imaging

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