The Princeton Full Correlation Matrix Analysis (FCMA) Toolbox is a suite of tools for correlating, analyzing, and classifying patterns of correlation in fMRI time-series data.

The key data structure in FCMA is the Full Correlation Matrix (FCM), which contains the correlations between all pairs of voxels and time-intervals. Computing the entire FCM is intractable: the FCM for two one-hour fMRI sessions requires approx. 1.5 x 1019 correlations, nearly 20 years of compute time on a 4000-core computer cluster. The FCMA Toolbox correlates a given set of fixed time-intervals (blocks of TRs you specify) which together with some custom optimizations reduces the computational load to a matter of hours. A modest-sized cluster is still required to do unbiased calculations-- ones that use a wholebrain mask initially rather than depending on a preselected ROI based on activation (such as a GLM or an ANOVA). This is due to the ~40k voxels that will undergo autocorrelation and classification.

Here are the steps for running an FCMA analysis from a user perspective, including how to create an .fcma config file, without discussing the config settings in detail. Please see the config file and reference page for that, and the FCMA Tutorial for a discussion in the context of a real analysis. As far as how to install FCMA and set up a machine or cluster of machines, system administrators should consult the cluster page.

Using FCMA



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