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Poster
Shared Independent Component Analysis for Multi-Subject Neuroimaging
Hugo Richard · Pierre Ablin · Bertrand Thirion · Alexandre Gramfort · Aapo Hyvarinen

Thu Dec 09 08:30 AM -- 10:00 AM (PST) @
in Poster Session 6 »

We consider shared response modeling, a multi-view learning problem where one wants to identify common components from multiple datasets or views. We introduce Shared Independent Component Analysis (ShICA) that models eachview as a linear transform of shared independent components contaminated by additive Gaussian noise. We show that this model is identifiable if the components are either non-Gaussian or have enough diversity in noise variances. We then show that in some cases multi-set canonical correlation analysis can recover the correct unmixing matrices, but that even a small amount of sampling noise makes Multiset CCA fail. To solve this problem, we propose to use joint diagonalization after Multiset CCA, leading to a new approach called ShICA-J. We show via simulations that ShICA-J leads to improved results while being very fast to fit. While ShICA-J is based on second-order statistics, we further propose to leverage non-Gaussianity of the components using a maximum-likelihood method, ShICA-ML, that is both more accurate and more costly. Further, ShICA comes with a principled method for shared components estimation. Finally, we provide empirical evidence on fMRI and MEG datasets that ShICA yields more accurate estimation of the componentsthan alternatives.

Keywords: Representation Learning

Author Information

Hugo Richard (INRIA)
Pierre Ablin (INRIA)
Bertrand Thirion (INRIA)
Alexandre Gramfort (INRIA)
Aapo Hyvarinen (University of Helsinki)

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