Identification of the hemodynamic response function from functional magnetic resonance imaging data

Functional magnetic resonance imaging (fMRI) is a noninvasive technique used to detect brain activity. It utilizes the fact that the magnetic resonance signal intensity is correlated with the cerebral blood flow, which in turn is correlated with neural activity [4]. Hence, fMRI can localize brain regions that show significant neural activity upon stimulus presentation, where the stimulus is designed to activate the sensory, motor or cognitive task under study. fMRI data sets typically consist of time series associated with the voxels of the brain. For each voxel, the significance of the response to the stimulus is assessed by statistically analyzing the associated fMRI time series. In this way, brain activation maps, or statistical parametric maps (SPMs), can be constructed.