Unsupervised robust nonparametric estimation of the hemodynamic response function for any fMRI experiment. - Archive ouverte HAL Access content directly
Journal Articles IEEE Transactions on Medical Imaging Year : 2003

Unsupervised robust nonparametric estimation of the hemodynamic response function for any fMRI experiment.

(1, 2) , (3) , (4, 5) , (6) , (1, 7) , (5, 8, 9)
1
2
3
4
5
6
7
8
9

Abstract

This paper deals with the estimation of the blood oxygen level-dependent response to a stimulus, as measured in functional magnetic resonance imaging (fMRI) data. A precise estimation is essential for a better understanding of cerebral activations. The most recent works have used a nonparametric framework for this estimation, considering each brain region as a system characterized by its impulse response, the so-called hemodynamic response function (HRF). However, the use of these techniques has remained limited since they are not well-adapted to real fMRI data. Here, we develop a threefold extension to previous works. We consider asynchronous event-related paradigms, account for different trial types and integrate several fMRI sessions into the estimation. These generalizations are simultaneously addressed through a badly conditioned observation model. Bayesian formalism is used to model temporal prior information of the underlying physiological process of the brain hemodynamic response. By this way, the HRF estimate results from a tradeoff between information brought by the data and by our prior knowledge. This tradeoff is modeled with hyperparameters that are set to the maximum-likelihood estimate using an expectation conditional maximization algorithm. The proposed unsupervised approach is validated on both synthetic and real fMRI data, the latter originating from a speech perception experiment.
Fichier principal
Vignette du fichier
Ciuciu03-TMI.pdf (576.21 Ko) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

cea-00333694 , version 1 (23-10-2008)

Identifiers

Cite

Philippe Ciuciu, Jean-Baptiste Poline, Guillaume Marrelec, Jérôme Idier, Christophe Pallier, et al.. Unsupervised robust nonparametric estimation of the hemodynamic response function for any fMRI experiment.. IEEE Transactions on Medical Imaging, 2003, 22 (10), pp.1235-51. ⟨10.1109/TMI.2003.817759⟩. ⟨cea-00333694⟩
438 View
748 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More