[ { "key": "3VCKQNU5", "version": 1, "library": { "type": "group", "id": 42081, "name": "hires fMRI", "links": { "alternate": { "href": "https://www.zotero.org/groups/hires_fmri", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/42081/items/3VCKQNU5", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/hires_fmri/items/3VCKQNU5", "type": "text/html" } }, "meta": { "createdByUser": { "id": 331964, "username": "nikokri", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/nikokri", "type": "text/html" } } }, "creatorSummary": "Shmuel et al.", "parsedDate": "2010", "numChildren": 0 }, "data": { "key": "3VCKQNU5", "version": 1, "itemType": "journalArticle", "title": "Mechanisms underlying decoding at 7 T: Ocular dominance columns, broad structures, and macroscopic blood vessels in V1 convey information on the stimulated eye", "creators": [ { "creatorType": "author", "firstName": "A.", "lastName": "Shmuel" }, { "creatorType": "author", "firstName": "D.", "lastName": "Chaimow" }, { "creatorType": "author", "firstName": "G.", "lastName": "Raddatz" }, { "creatorType": "author", "firstName": "K.", "lastName": "Ugurbil" }, { "creatorType": "author", "firstName": "E.", "lastName": "Yacoub" } ], "abstractNote": "", "publicationTitle": "Neuroimage", "publisher": "", "place": "", "date": "2010", "volume": "49", "issue": "3", "section": "", "partNumber": "", "partTitle": "", "pages": "1957–1964", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "", "archive": "", "archiveLocation": "", "shortTitle": "Mechanisms underlying decoding at 7 T", "language": "", "libraryCatalog": "Google Scholar", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2011-07-28T17:33:56Z", "dateModified": "2011-07-28T17:33:56Z" } }, { "key": "XA4K6DI5", "version": 1, "library": { "type": "group", "id": 42081, "name": "hires fMRI", "links": { "alternate": { "href": "https://www.zotero.org/groups/hires_fmri", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/42081/items/XA4K6DI5", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/hires_fmri/items/XA4K6DI5", "type": "text/html" } }, "meta": { "createdByUser": { "id": 331964, "username": "nikokri", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/nikokri", "type": "text/html" } } }, "creatorSummary": "Shmuel et al.", "parsedDate": "2007", "numChildren": 0 }, "data": { "key": "XA4K6DI5", "version": 1, "itemType": "journalArticle", "title": "Spatio-temporal point-spread function of fMRI signal in human gray matter at 7 Tesla", "creators": [ { "creatorType": "author", "firstName": "A.", "lastName": "Shmuel" }, { "creatorType": "author", "firstName": "E.", "lastName": "Yacoub" }, { "creatorType": "author", "firstName": "D.", "lastName": "Chaimow" }, { "creatorType": "author", "firstName": "N. K", "lastName": "Logothetis" }, { "creatorType": "author", "firstName": "K.", "lastName": "Ugurbil" } ], "abstractNote": "", "publicationTitle": "Neuroimage", "publisher": "", "place": "", "date": "2007", "volume": "35", "issue": "2", "section": "", "partNumber": "", "partTitle": "", "pages": "539–552", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "", "citationKey": "", "url": "", "accessDate": "", "PMID": "", "PMCID": "", "ISSN": "", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "Google Scholar", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2011-07-28T17:33:56Z", "dateModified": "2011-07-28T17:33:56Z" } }, { "key": "JBFU2FIH", "version": 1, "library": { "type": "group", "id": 42081, "name": "hires fMRI", "links": { "alternate": { "href": "https://www.zotero.org/groups/hires_fmri", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/42081/items/JBFU2FIH", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/hires_fmri/items/JBFU2FIH", "type": "text/html" } }, "meta": { "createdByUser": { "id": 331964, "username": "nikokri", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/nikokri", "type": "text/html" } } }, "creatorSummary": "Sasaki et al.", "parsedDate": "2006-09-07", "numChildren": 0 }, "data": { "key": "JBFU2FIH", "version": 1, "itemType": "journalArticle", "title": "The radial bias: a different slant on visual orientation sensitivity in human and nonhuman primates", "creators": [ { "creatorType": "author", "firstName": "Yuka", "lastName": "Sasaki" }, { "creatorType": "author", "firstName": "Reza", "lastName": "Rajimehr" }, { "creatorType": "author", "firstName": "Byoung Woo", "lastName": "Kim" }, { "creatorType": "author", "firstName": "Leeland B", "lastName": "Ekstrom" }, { "creatorType": "author", "firstName": "Wim", "lastName": "Vanduffel" }, { "creatorType": "author", "firstName": "Roger B H", "lastName": "Tootell" } ], "abstractNote": "It is generally assumed that sensitivity to different stimulus orientations is mapped in a globally equivalent fashion across primate visual cortex, at a spatial scale larger than that of orientation columns. However, some evidence predicts instead that radial orientations should produce higher activity than other orientations, throughout visual cortex. Here, this radial orientation bias was robustly confirmed using (1) human psychophysics, plus fMRI in (2) humans and (3) behaving monkeys. In visual cortex, fMRI activity was at least 20% higher in the retinotopic representations of polar angle which corresponded to the radial stimulus orientations (relative to tangential). In a global demonstration of this, we activated complementary retinotopic quadrants of visual cortex by simply changing stimulus orientation, without changing stimulus location in the visual field. This evidence reveals a neural link between orientation sensitivity and the cortical retinotopy, which have previously been considered independent.", "publicationTitle": "Neuron", "publisher": "", "place": "", "date": "Sep 7, 2006", "volume": "51", "issue": "5", "section": "", "partNumber": "", "partTitle": "", "pages": "661-670", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Neuron", "DOI": "10.1016/j.neuron.2006.07.021", "citationKey": "", "url": "http://www.ncbi.nlm.nih.gov/pubmed/16950163", "accessDate": "2011-07-28T17:33:26Z", "PMID": "", "PMCID": "", "ISSN": "0896-6273", "archive": "", "archiveLocation": "", "shortTitle": "The radial bias", "language": "", "libraryCatalog": "NCBI PubMed", "callNumber": "", "rights": "", "extra": "PMID: 16950163", "tags": [ { "tag": "Animals", "type": 1 }, { "tag": "Bias (Epidemiology)", "type": 1 }, { "tag": "Brain Mapping", "type": 1 }, { "tag": "Contrast Sensitivity", "type": 1 }, { "tag": "Humans", "type": 1 }, { "tag": "Macaca mulatta", "type": 1 }, { "tag": "Magnetic Resonance Imaging", "type": 1 }, { "tag": "Male", "type": 1 }, { "tag": "Orientation", "type": 1 }, { "tag": "Visual Cortex", "type": 1 } ], "collections": [], "relations": {}, "dateAdded": "2011-07-28T17:33:34Z", "dateModified": "2011-07-28T17:33:34Z" } }, { "key": "MTGFNBER", "version": 1, "library": { "type": "group", "id": 42081, "name": "hires fMRI", "links": { "alternate": { "href": "https://www.zotero.org/groups/hires_fmri", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/42081/items/MTGFNBER", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/hires_fmri/items/MTGFNBER", "type": "text/html" } }, "meta": { "createdByUser": { "id": 331964, "username": "nikokri", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/nikokri", "type": "text/html" } } }, "creatorSummary": "Clifford et al.", "parsedDate": "2009-11", "numChildren": 0 }, "data": { "key": "MTGFNBER", "version": 1, "itemType": "journalArticle", "title": "Radial biases in the processing of motion and motion-defined contours by human visual cortex", "creators": [ { "creatorType": "author", "firstName": "Colin W G", "lastName": "Clifford" }, { "creatorType": "author", "firstName": "Damien J", "lastName": "Mannion" }, { "creatorType": "author", "firstName": "J Scott", "lastName": "McDonald" } ], "abstractNote": "Luminance gratings reportedly produce a stronger functional magnetic resonance imaging (fMRI) blood oxygen level-dependent (BOLD) signal in those parts of the retinotopic cortical maps where they are oriented radially to the point of fixation. We sought to extend this finding by examining anisotropies in the response of cortical areas V1-V3 to motion-defined contour stimuli. fMRI at 3 Tesla was used to measure the BOLD signal in the visual cortex of six human subjects. Stimuli were composed of strips of spatial white noise texture presented in an annular window. The texture in alternate strips moved in opposite directions (left-right or up-down). The strips themselves were static and tilted 45 degrees left or right from vertical. Comparison with maps of the visual field obtained from phase-encoded retinotopic analysis revealed systematic patterns of radial bias. For motion, a stronger response to horizontal was evident within V1 and along the borders between V2 and V3. For orientation, the response to leftward tilted contours was greater in left dorsal and right ventral V1-V3. Radial bias for the orientation of motion-defined contours analogous to that reported previously for luminance gratings could reflect cue-invariant processing or the operation of distinct mechanisms subject to similar anisotropies in orientation tuning. Radial bias for motion might be related to the phenomenon of \"motion streaks,\" whereby temporal integration by the visual system introduces oriented blur along the axis of motion. We speculate that the observed forms of radial bias reflect a common underlying anisotropy in the representation of spatiotemporal image structure across the visual field.", "publicationTitle": "Journal of Neurophysiology", "publisher": "", "place": "", "date": "Nov 2009", "volume": "102", "issue": "5", "section": "", "partNumber": "", "partTitle": "", "pages": "2974-2981", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "J. Neurophysiol", "DOI": "10.1152/jn.00411.2009", "citationKey": "", "url": "http://www.ncbi.nlm.nih.gov/pubmed/19759326", "accessDate": "2011-07-28T16:32:18Z", "PMID": "", "PMCID": "", "ISSN": "1522-1598", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "NCBI PubMed", "callNumber": "", "rights": "", "extra": "PMID: 19759326", "tags": [ { "tag": "Adult", "type": 1 }, { "tag": "Bias (Epidemiology)", "type": 1 }, { "tag": "Brain Mapping", "type": 1 }, { "tag": "Female", "type": 1 }, { "tag": "Functional Laterality", "type": 1 }, { "tag": "Humans", "type": 1 }, { "tag": "Image Processing, Computer-Assisted", "type": 1 }, { "tag": "Magnetic Resonance Imaging", "type": 1 }, { "tag": "Male", "type": 1 }, { "tag": "Motion Perception", "type": 1 }, { "tag": "Orientation", "type": 1 }, { "tag": "Oxygen", "type": 1 }, { "tag": "Photic Stimulation", "type": 1 }, { "tag": "Psychophysics", "type": 1 }, { "tag": "Visual Cortex", "type": 1 }, { "tag": "Visual Fields", "type": 1 }, { "tag": "Young Adult", "type": 1 } ], "collections": [], "relations": {}, "dateAdded": "2011-07-28T17:32:33Z", "dateModified": "2011-07-28T17:32:33Z" } }, { "key": "4B9HDZ9X", "version": 1, "library": { "type": "group", "id": 42081, "name": "hires fMRI", "links": { "alternate": { "href": "https://www.zotero.org/groups/hires_fmri", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/42081/items/4B9HDZ9X", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/hires_fmri/items/4B9HDZ9X", "type": "text/html" } }, "meta": { "createdByUser": { "id": 331964, "username": "nikokri", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/nikokri", "type": "text/html" } } }, "creatorSummary": "Mannion et al.", "parsedDate": "2009-06", "numChildren": 0 }, "data": { "key": "4B9HDZ9X", "version": 1, "itemType": "journalArticle", "title": "Discrimination of the local orientation structure of spiral Glass patterns early in human visual cortex", "creators": [ { "creatorType": "author", "firstName": "D J", "lastName": "Mannion" }, { "creatorType": "author", "firstName": "J S", "lastName": "McDonald" }, { "creatorType": "author", "firstName": "C W G", "lastName": "Clifford" } ], "abstractNote": "The local orientation structure of a visual image is fundamental to the perception of spatial form. Reports of reliable orientation-selective modulations in the pattern of fMRI activity have demonstrated the potential for investigating the representation of orientation in the human visual cortex. Orientation-selective voxel responses could arise from anisotropies in the preferred orientations of pooled neurons due to the random sampling of the cortical surface. However, it is unclear whether orientation-selective voxel responses reflect biases in the underlying distribution of neuronal orientation preference, such as the demonstrated over-representation of radial orientations (those collinear with fixation). Here, we investigated whether stimuli balanced in their radial components could evoke orientation-selective biases in voxel activity. We attempted to discriminate the sense of spiral Glass patterns (opening anti-clockwise or clockwise), in which the local orientation structure was defined by the placement of paired dots at an orientation offset from the radial. We found that information within the spatial pattern of fMRI responses in each of V1, V2, V3, and V3A/B allowed discrimination of the spiral sense with accuracies significantly above chance. This result demonstrates that orientation-selective voxel responses can arise without the influence of a radial bias. Furthermore, the finding indicates the importance of the early visual areas in representing the local orientation structure for the perception of complex spatial form.", "publicationTitle": "NeuroImage", "publisher": "", "place": "", "date": "Jun 2009", "volume": "46", "issue": "2", "section": "", "partNumber": "", "partTitle": "", "pages": "511-515", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "Neuroimage", "DOI": "", "citationKey": "", "url": "http://www.ncbi.nlm.nih.gov/pubmed/19385017", "accessDate": "2011-07-28T16:32:18Z", "PMID": "", "PMCID": "", "ISSN": "1095-9572", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "NCBI PubMed", "callNumber": "", "rights": "", "extra": "PMID: 19385017", "tags": [ { "tag": "Brain Mapping", "type": 1 }, { "tag": "Evoked Potentials, Visual", "type": 1 }, { "tag": "Humans", "type": 1 }, { "tag": "Magnetic Resonance Imaging", "type": 1 }, { "tag": "Pattern Recognition, Visual", "type": 1 }, { "tag": "Visual Cortex", "type": 1 } ], "collections": [], "relations": {}, "dateAdded": "2011-07-28T17:32:25Z", "dateModified": "2011-07-28T17:32:25Z" } }, { "key": "4C9996IU", "version": 1, "library": { "type": "group", "id": 42081, "name": "hires fMRI", "links": { "alternate": { "href": "https://www.zotero.org/groups/hires_fmri", "type": "text/html" } } }, "links": { "self": { "href": "https://api.zotero.org/groups/42081/items/4C9996IU", "type": "application/json" }, "alternate": { "href": "https://www.zotero.org/groups/hires_fmri/items/4C9996IU", "type": "text/html" } }, "meta": { "createdByUser": { "id": 331964, "username": "nikokri", "name": "", "links": { "alternate": { "href": "https://www.zotero.org/nikokri", "type": "text/html" } } }, "creatorSummary": "Swisher et al.", "parsedDate": "2010-01-06", "numChildren": 0 }, "data": { "key": "4C9996IU", "version": 1, "itemType": "journalArticle", "title": "Multiscale Pattern Analysis of Orientation-Selective Activity in the Primary Visual Cortex", "creators": [ { "creatorType": "author", "firstName": "Jascha D.", "lastName": "Swisher" }, { "creatorType": "author", "firstName": "J. Christopher", "lastName": "Gatenby" }, { "creatorType": "author", "firstName": "John C.", "lastName": "Gore" }, { "creatorType": "author", "firstName": "Benjamin A.", "lastName": "Wolfe" }, { "creatorType": "author", "firstName": "Chan-Hong", "lastName": "Moon" }, { "creatorType": "author", "firstName": "Seong-Gi", "lastName": "Kim" }, { "creatorType": "author", "firstName": "Frank", "lastName": "Tong" } ], "abstractNote": "Although orientation columns are less than a millimeter in width, recent neuroimaging studies indicate that viewed orientations can be decoded from cortical activity patterns sampled at relatively coarse resolutions of several millimeters. One proposal is that these differential signals arise from random spatial irregularities in the columnar map. However, direct support for this hypothesis has yet to be obtained. Here, we used high-field, high-resolution functional magnetic resonance imaging (fMRI) and multivariate pattern analysis to determine the spatial scales at which orientation-selective information can be found in the primary visual cortex (V1) of cats and humans. We applied a multiscale pattern analysis approach in which fine- and coarse-scale signals were first removed by ideal spatial lowpass and highpass filters, and the residual activity patterns then analyzed by linear classifiers. Cat visual cortex, imaged at 0.3125 mm resolution, showed a strong orientation signal at the scale of individual columns. Nonetheless, reliable orientation bias could still be found at spatial scales of several millimeters. In the human visual cortex, imaged at 1 mm resolution, a majority of orientation information was found on scales of millimeters, with small contributions from global spatial biases exceeding ∼1 cm. Our high-resolution imaging results demonstrate a reliable millimeters-scale orientation signal, likely emerging from irregular spatial arrangements of orientation columns and their supporting vasculature. fMRI pattern analysis methods are thus likely to be sensitive to signals originating from other irregular columnar structures elsewhere in the brain.", "publicationTitle": "The Journal of Neuroscience", "publisher": "", "place": "", "date": "January 06 , 2010", "volume": "30", "issue": "1", "section": "", "partNumber": "", "partTitle": "", "pages": "325 -330", "series": "", "seriesTitle": "", "seriesText": "", "journalAbbreviation": "", "DOI": "10.1523/JNEUROSCI.4811-09.2010", "citationKey": "", "url": "http://www.jneurosci.org/content/30/1/325.abstract", "accessDate": "2011-07-12T15:50:06Z", "PMID": "", "PMCID": "", "ISSN": "", "archive": "", "archiveLocation": "", "shortTitle": "", "language": "", "libraryCatalog": "Highwire 2.0", "callNumber": "", "rights": "", "extra": "", "tags": [], "collections": [], "relations": {}, "dateAdded": "2011-07-12T15:50:20Z", "dateModified": "2011-07-12T15:50:20Z" } } ]