Sparse dictionary learning for fMRI analysis using autocorrelation maximization

Muhammad Usman Khalid, Adnan Shah, Abd Krim Seghouane

    Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

    12 Citations (Scopus)

    Abstract

    In this paper, the effect of temporal autocorrelations in functional magnetic resonance imaging (fMRI) data on sparse dictionary learning (SDL) is addressed. For sparse general linear model (sGLM), the fMRI time-series is modeled as a linear mixture of several signals such as neural dynamics, structured noise, random noise and unexplained signal variations on the basis of spatial sparseness. These signals are considered as underlying sources and SDL is used to estimate them. However, the sparse GLM model does not take into account the autocorrelations in fMRI data. To address this shortcoming, a new model is proposed to incorporate the prior knowledge about lag-1 autocorrelation into dictionary update stage. This helps improve the sensitivity and specificity of the fMRI data during statistical analysis. Using a simulation study, the effect of the proposed dictionary update on sGLM is compared to conventional sGLM by utilizing various detrending techniques. Furthermore, the proposed update is validated in an sGLM framework for real fMRI datasets, which shows its better capability to estimate neural dynamics in presence of spatiotemporal dependencies.

    Original languageEnglish
    Title of host publication2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2015
    PublisherInstitute of Electrical and Electronics Engineers Inc.
    Pages4286-4289
    Number of pages4
    ISBN (Electronic)9781424492718
    DOIs
    Publication statusPublished - 4 Nov 2015
    Event37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2015 - Milan, Italy
    Duration: 25 Aug 201529 Aug 2015

    Publication series

    NameProceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS
    Volume2015-November
    ISSN (Print)1557-170X

    Conference

    Conference37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2015
    Country/TerritoryItaly
    CityMilan
    Period25/08/1529/08/15

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