Fig. 1.

General Approach. A) The brain is an example of a convolu-tional system when viewed through BOLD fMRI. Dynamics among brain regions are highly nonlinear and usually cannot be directly observed. B) Measurements made using fMRI reflect latent brain activity passing through a hemodynamic response function (HRF). C) Surrogate Deconvolution workflow: a deconvolution surface is estimated by sampling the time-series deconvolution across a variety of kernel parameters (left). A separate surrogate model is formed for each time-point using basis regression to approximate this surface (middle). The combined surrogate models then represent the deconvolution process during parameter estimation