Bayesian spatiotemporal model for detecting of active areas in brain for analyzing of fMRI data

Abstract

Introduction: In recent years, Functional Magnetic Resonance Imaging (fMRI) has been highly regarded for determining activated areas of brain in different conditions. Statistical methods have a crucial role in analyzing fMRI data. These data have complicated 3-dimentional spatial and temporal correlation structures. Also, there is a time lapse between the stimulus onset and response, which is known as Hemodynamic Response Function (HRF). It is very important to consider the complex correlation structures and the behavior of HRF in statistical modeling. In present paper, a Bayesian spatiotemporal model is introduced that is applied to analyze fMRI data for detecting the activated areas of brain. Materials and Methods: Images related to 2-back task, obtained from a part of the My Connectome Project, was used that is implemented in Stanford University in 2015. The 3D spatiotemporal proposed model was fitted on the data, so that HRF is estimated for each voxel based on its data, separately, and complex correlation structures are also considered. FSL software was used for preprocessing of images and Matlab software was used for statistical modeling. Results: The results of statistical models show that some parts of inferior parietal and also frontal areas were activated by the task. Conclusion: A Bayesian spatiotemporal model was introduced as a suitable method for identifying activated areas in fMRI time series. Because of considering both of complex correlation structures and estimated HRF, our proposed model can be a perfect approach for analyzing of these data