TY - GEN
T1 - Selection of temporal models for event-related fMRI
AU - Donnet, Sophie
AU - Lavielle, Marc
AU - Ciuciu, Philippe
AU - Paline, Jean Baptiste
PY - 2004/1/1
Y1 - 2004/1/1
N2 - In functional Magnetic Resonance Imaging (fMRI), recent works have addressed the non parametric estimation of the Hemodynamic Response Function (HRF) under linearity and stationarity in time hypotheses. We propose to test a more flexible model that allows for the variation of the magnitude of the HRF with time. Under this model, the magnitude of the HRF evoked by a single event may vary with other occurrences of the same kind of event. This model is tested against a simpler model with a fixed magnitude. We develop a stochastic version of the EM algorithm to identify the magnitudes and the HRF. We also address the problem of model specification. It is usually assumed that every event type evokes a response. Our scheme uses a model selection approach which provides the best subset of event types maximizing the likelihood of the fMRI signal. Our methodology is exemplified by simulated and fMRI data.
AB - In functional Magnetic Resonance Imaging (fMRI), recent works have addressed the non parametric estimation of the Hemodynamic Response Function (HRF) under linearity and stationarity in time hypotheses. We propose to test a more flexible model that allows for the variation of the magnitude of the HRF with time. Under this model, the magnitude of the HRF evoked by a single event may vary with other occurrences of the same kind of event. This model is tested against a simpler model with a fixed magnitude. We develop a stochastic version of the EM algorithm to identify the magnitudes and the HRF. We also address the problem of model specification. It is usually assumed that every event type evokes a response. Our scheme uses a model selection approach which provides the best subset of event types maximizing the likelihood of the fMRI signal. Our methodology is exemplified by simulated and fMRI data.
U2 - 10.1109/ISBI.2004.1398707
DO - 10.1109/ISBI.2004.1398707
M3 - Conference contribution
AN - SCOPUS:17144428620
SN - 0780383885
SN - 9780780383883
T3 - 2004 2nd IEEE International Symposium on Biomedical Imaging: Macro to Nano
SP - 992
EP - 995
BT - 2004 2nd IEEE International Symposium on Biomedical Imaging
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2nd IEEE International Symposium on Biomedical Imaging: Macro to Nano, ISBI 2004
Y2 - 18 April 2004 through 18 April 2004
ER -