Detecting changes in the covariance structure of functional time series with application to fMRI data
نویسندگان
چکیده
Functional magnetic resonance imaging (fMRI) data provides information concerning activity in the brain and particular interactions between regions. Resting state fMRI is widely used for inferring connectivities which are not due to external factors. As such analyzes strongly rely on stationarity, change point procedures can be applied order detect possible deviations from this crucial assumption. FMRI modeled as functional time series tools detection of covariance stationarity via alternatives developed. A nonparametric procedure based dimension reduction techniques proposed. However, projection a finite rather low-dimensional subspace involves risk missing changes orthogonal space, two test statistics take full structure into account considered. The proposed methods compared simulation study more than 100 resting sets.
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ژورنال
عنوان ژورنال: Econometrics and Statistics
سال: 2021
ISSN: ['2452-3062', '2468-0389']
DOI: https://doi.org/10.1016/j.ecosta.2020.04.004