MultiVoxelPatternAnalysis - MRC CBU Imaging Wiki

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Multi-voxel pattern analysis

Traditional neuroimaging analysis techniques are designed to detect the "activation" of neural structures that are at least a centimetre or so in scale. However, a growing number of studies have shown that substantial information can be obtained from the fMRI signal at a scale that is smaller than this. To do this, pattern classifiers are used to relate distinct patterns of activation within a brain region to corresponding mental states (e.g., stimuli). Although the pattern is generally idiosyncratic in that it varies from one person to the next, within subjects, reliable correspondences can be found.

MVPA has been shown to reveal information within brain regions that was lost in previous fMRI analyses, such as sensitivity to orientation in V1.

Many different classifiers have been used to build the correspondence between activity pattern and mental state, including correlation, linear-discriminant analysis and support vector machines. In some studies, just one a priori region-of-interest is examined, in others the whole brain classified (so providing no specificity), and in others, a roving "searchlight" is used to examine the whole brain one region at a time.

MvpaPapersOfInterest

Meeting

There is a weekly Representational Similarity Analysis Interests Group (RSAIG) meeting to discuss method development and applications of MVPA. Topics have covered in the past related to Multivariate Pattern Analysis (MVPA). For instance, Representational Similarity Analysis (RSA) as the list name suggests and various pattern classification approaches to fMRI and E/MEG analysis. For more detail of this meeting, please contact the group coordinator Li Su. To subscribe or unsubscribe the mailing list, please visit: http://lists.mrc-cbu.cam.ac.uk/mailman/listinfo/rsaig. The mailing list hosts more than 30 members of the Unit and researchers in the University. It publish the topics of each meeting and circulate information on the RSA toolbox.

There are also other periodic meetings at the CBU to discuss this topic. See MriPhysicsAndAnalysisForCognitiveNeuroscientists