3D spatial analysis of fMRI data: a comparison of ICA and GLM analysis on a word perception task

We discuss a comparative 3D spatial analysis of fMRI data taken during a combined word perception and motor task. We show that a classical GLM analysis using SPM does not yield reasonable results. Only with BSS techniques using the fastICA algorithm can we get meaningful and interesting results. The event-based experiment was part of a study to investigate the network of neurons involved in the perception of speech and the decoding of auditory speech stimuli. Corresponding to 4 different stimuli different independent components (IC) could be identified in the auditory cortex and, most interesting, an IC representing a network of 3 simultaneously active areas in the inferior frontal gyrus could be detected.