Consistency of Regions of Interest as nodes of fMRI functional brain networks

dc.contributorAalto Universityen
dc.contributor.authorKorhonen, Onerva
dc.contributor.authorSaarimäki, Heini
dc.contributor.authorGlerean, Enrico
dc.contributor.authorSams, Mikko
dc.contributor.authorSaramäki, Jari
dc.contributor.departmentDepartment of Neuroscience and Biomedical Engineering
dc.contributor.departmentDepartment of Computer Science
dc.description.abstractThe functional network approach, where fMRI BOLD time series are mapped to networks depicting functional relationships between brain areas, has opened new insights into the function of the human brain. In this approach, the choice of network nodes is of crucial importance. One option is to consider fMRI voxels as nodes. This results in a large number of nodes, making network analysis and interpretation of results challenging. A common alternative is to use predefined clusters of anatomically close voxels, Regions of Interest (ROIs). This approach assumes that voxels within ROIs are functionally similar. Because these two approaches result in different network structures, it is crucial to understand what happens to network connectivity when moving from the voxel level to the ROI level. We show that the consistency of ROIs, defined as the mean Pearson correlation coefficient between the time series of their voxels, varies widely in resting-state experimental data. Therefore the assumption of similar voxel dynamics within each ROI does not generally hold. Further, the time series of low-consistency ROIs may be highly correlated, resulting in spurious links in ROI-level networks. Based on these results, we recommend that averaging BOLD signals over anatomically defined ROIs should be carefully considered.en
dc.description.versionPeer revieweden
dc.identifier.citationKorhonen , O , Saarimäki , H , Glerean , E , Sams , M & Saramäki , J 2017 , ' Consistency of Regions of Interest as nodes of fMRI functional brain networks ' , Network Neuroscience , vol. 1 , no. 3 , pp. 254-274 .
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dc.relation.ispartofseriesNetwork Neuroscienceen
dc.relation.ispartofseriesVolume 1, issue 3en
dc.subject.keywordfunctional magnetic resonance imaging
dc.subject.keywordfunctional brain networks
dc.subject.keywordnode definition
dc.subject.keywordRegion of Interest
dc.subject.keywordanatomical atlas
dc.subject.keywordbrain parcellation
dc.titleConsistency of Regions of Interest as nodes of fMRI functional brain networksen
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi