Analysis of visual cortex-event-related fMRI data using ICA decomposition
Bulbul Ahmed, Arif Ul Alam, Md. Abdullah Al Mamun, Muhammad E. H. Chowdhury, Tamnun E. Mursalin · International Journal of Biomedical Engineering and Technology · 2011
Independent Component Analysis (ICA) of Functional Magnetic Resonance Imaging (fMRI) data is commonly carried out under the assumption that each source may be represented as a spatially fixed pattern of activation. In this work, to detect and visualise variations in single-trial Hemodynamic Responses (HR) in event-related fMRI data, Infomax ICA algorithm has been used. Six subjects participated in four fMRI sessions. ICA decomposition of the resulting Blood Oxygenation Level-Dependent (BOLD) data from each session produced an independent component active in primary visual cortex. The BOLD-image plots demonstrated that component HRs varied substantially and often systematically across trials as well as across sessions, subjects, and brain areas.