Towards whole brain mapping of the hemodynamic response function

We characterized a deconvolved haemodynamic response function (dHRF) across the whole cortex exploiting a sine series expansion in a cohort of young healthy subjects from the Human Connectome Project. We report, for different tasks and brain regions, the amplitude, latency, time-to-peak and full-width at half maximum of the fitted BOLD response and of the dHRF. We show that each of those parameters varies throughout the cortex and, to a smaller extent, across subjects. Additionally, the use of a flexible model, like the one we explored in this study, reveals that the HRF in some brain regions deviates from canonicity.