Skip navigation
Skip navigation

Multifocal fMRI mapping of visual cortical areas

Vanni, S; Henriksson, L.; James, Andrew

Description

The multifocal mapping of electroretinograms and visual evoked potentials has established an important role in both basic research and in diagnostic procedures. We have developed a multifocal mapping method for fMRI, which allows detailed analysis of multiple local visual field representations in the cortex with excellent spatial resolution. Visual field was divided into 60 regions in a dartboard configuration, scaled according to the human magnification factor. Within blocks of 7 s, half of...[Show more]

dc.contributor.authorVanni, S
dc.contributor.authorHenriksson, L.
dc.contributor.authorJames, Andrew
dc.date.accessioned2015-12-13T22:35:25Z
dc.identifier.issn1053-8119
dc.identifier.urihttp://hdl.handle.net/1885/76585
dc.description.abstractThe multifocal mapping of electroretinograms and visual evoked potentials has established an important role in both basic research and in diagnostic procedures. We have developed a multifocal mapping method for fMRI, which allows detailed analysis of multiple local visual field representations in the cortex with excellent spatial resolution. Visual field was divided into 60 regions in a dartboard configuration, scaled according to the human magnification factor. Within blocks of 7 s, half of the regions were stimulated with checkerboard patterns contrast reversing at 8 reversals per second, while the other half remained inactive at uniform luminance. The subset of active regions changed with each 7-s block, according to an orthogonal design. Functional MRI was done with a 3-T GE Signa and analyzed with SPM2. A general linear model was fitted producing activation maps for each of the 60 regions, and local signal changes were quantified from V1. These activation maps were next assigned to 3D surface models of the cortical sheet, and then unfolded, using the Brain à la Carte software package. Phase-encoded retinotopic analysis of conventional design served as qualitative comparison data. With multifocal fMRI, all regions were mapped with good signal-to-noise ratio in V1, and subsets of regions showed activation in V2 and V3. This method allows rapid and direct exploration of multiple local visual responses, and is thus able to give complementary information to phase encoded mapping of retinotopic areas.
dc.publisherAcademic Press
dc.sourceNeuroimage
dc.subjectKeywords: adult; article; computer program; controlled study; female; human; luminance; male; normal human; nuclear magnetic resonance imaging; priority journal; signal detection; signal noise ratio; statistical model; visual cortex; visual field; Adult; Brain Mapp Multifocal fMRI; Primary visual cortex; Retinotopic mapping; Visual field
dc.titleMultifocal fMRI mapping of visual cortical areas
dc.typeJournal article
local.description.notesImported from ARIES
local.description.refereedYes
local.identifier.citationvolume27
dc.date.issued2005
local.identifier.absfor110903 - Central Nervous System
local.identifier.ariespublicationMigratedxPub5399
local.type.statusPublished Version
local.contributor.affiliationVanni, S, Helsinki University of Technology
local.contributor.affiliationHenriksson, L., Helsinki University of Technology
local.contributor.affiliationJames, Andrew, College of Medicine, Biology and Environment, ANU
local.description.embargo2037-12-31
local.bibliographicCitation.startpage95
local.bibliographicCitation.lastpage105
local.identifier.doi10.1016/j.neuroimage.2005.01.046
dc.date.updated2015-12-11T09:27:54Z
local.identifier.scopusID2-s2.0-22044438268
CollectionsANU Research Publications

Download

File Description SizeFormat Image
01_Vanni_Multifocal_fMRI_mapping_of_2005.pdf826.02 kBAdobe PDF    Request a copy


Items in Open Research are protected by copyright, with all rights reserved, unless otherwise indicated.

Updated:  19 May 2020/ Responsible Officer:  University Librarian/ Page Contact:  Library Systems & Web Coordinator