Functional magnetic resonance imaging (fMRI) of the blood oxygen level dependent (BOLD) response has commonly been used to investigate the neuropathology by examining the positive phase of the BOLD response, assuming a fixed shape for the hemodynamic response function (HRF). However, the individual phases of the HRF may be characterized by different trend as a function of the brain areas activated. In this project, we want realise a statistical brain map of these characteristics. The results will bring on a better interpretation of hemodynamic response estimates across a wide variety of psychological and neuroscientific studies, because better it will the reconstruction of the BOLD if will use a HRF. We plan to leverage on the HCP dataset (freely available) to investigate the spatial variability of HRF corresponding to the various available stimulations.
The goal of the project is obtain a statistical brain map of the hemodynamic response functions as a function of the brain areas active. We focus on estimation of response amplitude/height, time-to-peak, and full-width at half-max in the HRF as potential measures of response magnitude. Actually, the choice of the HRF range fails from the use of a single canonical HRF obtained with a basis set of canonical function, well away from a real behaviour.