Dissecting cognitive stages with time-resolved fMRI data: a comparison of fuzzy clustering and independent component analysis. Export

@article{citeulike:1707378, abstract = {In combination with cognitive tasks entailing sequences of sensory and cognitive processes, event-related acquisition schemes allow using functional MRI to examine not only the topography but also the temporal sequence of cortical activation across brain regions (time-resolved fMRI). In this study, we compared two data-driven methods--fuzzy clustering method (FCM) and independent component analysis (ICA)--in the context of time-resolved fMRI data collected during the performance of a newly devised visual imagery task. We analyzed a multisubject fMRI data set using both methods and compared their results in terms of within- and between-subject consistency and spatial and temporal correspondence of obtained maps and time courses. Both FCM and spatial ICA allowed discriminating the contribution of distinct networks of brain regions to the main cognitive stages of the task (auditory perception, mental imagery and behavioural response), with good agreement across methods. Whereas ICA worked optimally on the original time series, averaging with respect to the task onset (and thus introducing some a priori information on the stimulation protocol) was found to be indispensable in the case of FCM. On averaged time series, FCM led to a richer decomposition of the spatio-temporal patterns of activation and allowed a finer separation of the neurocognitive processes subserving the mental imagery task. This study confirms the efficacy of the two examined methods in the data-driven estimation of hemodynamic responses in time-resolved fMRI studies and provides empirical guidelines to their use.}, address = {Vision Lab (Department of Physics), University of Antwerp, Universiteitsplein 1, B-2610 Antwerpen, Belgium.}, author = {Smolders, A. and De Martino, F. and Staeren, N. and Scheunders, P. and Sijbers, J. and Goebel, R. and Formisano, E.}, citeulike-article-id = {1707378}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.mri.2007.02.018}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/17482412}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=17482412}, doi = {10.1016/j.mri.2007.02.018}, issn = {0730-725X}, journal = {Magn Reson Imaging}, keywords = {clustering, fmri, ica}, month = {July}, number = {6}, pages = {860--868}, posted-at = {2007-09-29 07:58:34}, priority = {2}, title = {Dissecting cognitive stages with time-resolved fMRI data: a comparison of fuzzy clustering and independent component analysis.}, url = {http://dx.doi.org/10.1016/j.mri.2007.02.018}, volume = {25}, year = {2007} }

TY - JOUR ID - citeulike:1707378 L3 - citeulike-article-id:1707378 N2 - In combination with cognitive tasks entailing sequences of sensory and cognitive processes, event-related acquisition schemes allow using functional MRI to examine not only the topography but also the temporal sequence of cortical activation across brain regions (time-resolved fMRI). In this study, we compared two data-driven methods--fuzzy clustering method (FCM) and independent component analysis (ICA)--in the context of time-resolved fMRI data collected during the performance of a newly devised visual imagery task. We analyzed a multisubject fMRI data set using both methods and compared their results in terms of within- and between-subject consistency and spatial and temporal correspondence of obtained maps and time courses. Both FCM and spatial ICA allowed discriminating the contribution of distinct networks of brain regions to the main cognitive stages of the task (auditory perception, mental imagery and behavioural response), with good agreement across methods. Whereas ICA worked optimally on the original time series, averaging with respect to the task onset (and thus introducing some a priori information on the stimulation protocol) was found to be indispensable in the case of FCM. On averaged time series, FCM led to a richer decomposition of the spatio-temporal patterns of activation and allowed a finer separation of the neurocognitive processes subserving the mental imagery task. This study confirms the efficacy of the two examined methods in the data-driven estimation of hemodynamic responses in time-resolved fMRI studies and provides empirical guidelines to their use. IS - 6 JF - Magn Reson Imaging SN - 0730-725X AD - Vision Lab (Department of Physics), University of Antwerp, Universiteitsplein 1, B-2610 Antwerpen, Belgium. EP - 868 TI - Dissecting cognitive stages with time-resolved fMRI data: a comparison of fuzzy clustering and independent component analysis. VL - 25 SP - 860 KW - clustering KW - fmri KW - ica AU - Smolders, A AU - De Martino, F AU - Staeren, N AU - Scheunders, P AU - Sijbers, J AU - Goebel, R AU - Formisano, E PY - 2007/07// UR - http://dx.doi.org/10.1016/j.mri.2007.02.018 ER -