Inter-subject correlation in fMRI: Method validation against stimulus-model based analysis

Juha Pajula, Jukka Pekka Kauppi, Jussi Tohka

Research output: Contribution to journalArticleScientificpeer-review

31 Citations (Scopus)

Abstract

Within functional magnetic resonance imaging (fMRI), the use of the traditional general linear model (GLM) based analysis methods is often restricted to strictly controlled research setups requiring a parametric activation model. Instead, Inter-Subject Correlation (ISC) method is based on voxel-wise correlation between the time series of the subjects, which makes it completely non-parametric and thus suitable for naturalistic stimulus paradigms such as movie watching. In this study, we compared an ISC based analysis results with those of a GLM based in five distinct controlled research setups. We used International Consortium for Brain Mapping functional reference battery (FRB) fMRI data available from the Laboratory of Neuro Imaging image data archive. The selected data included measurements from 37 right-handed subjects, who all had performed the same five tasks from FRB. The GLM was expected to locate activations accurately in FRB data and thus provide good grounds for investigating relationship between ISC and stimulus induced fMRI activation. The statistical maps of ISC and GLM were compared with two measures. The first measure was the Pearson's correlation between the non-thresholded ISC test-statistics and absolute values of the GLM Z-statistics. The average correlation value over five tasks was 0.74. The second was the Dice index between the activation regions of the methods. The average Dice value over the tasks and three threshold levels was 0.73. The results of this study indicated how the data driven ISC analysis found the same foci as the model-based GLM analysis. The agreement of the results is highly interesting, because ISC is applicable in situations where GLM is not suitable, for example, when analyzing data from a naturalistic stimuli experiment.

Original languageEnglish
Article numbere41196
JournalPLoS ONE
Volume7
Issue number8
DOIs
Publication statusPublished - 8 Aug 2012
MoE publication typeA1 Journal article-refereed

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magnetic resonance imaging
Linear Models
Magnetic Resonance Imaging
linear models
Chemical activation
methodology
Brain Mapping
Brain mapping
Statistics
statistics
Neuroimaging
Motion Pictures
Research
Correlation methods
Time series
time series analysis
image analysis
brain

Cite this

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Inter-subject correlation in fMRI : Method validation against stimulus-model based analysis. / Pajula, Juha; Kauppi, Jukka Pekka; Tohka, Jussi.

In: PLoS ONE, Vol. 7, No. 8, e41196, 08.08.2012.

Research output: Contribution to journalArticleScientificpeer-review

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