@ARTICLE\{IMM2006-04750, author = "D. J. Jacobsen and K. H. Madsen and L. Hansen", title = "Bayesian model comparison in non-linear {BOLD} fMRI hemodynamics", year = "2006", keywords = "Bayes, model comparison, non-linear, {BOLD} fMRI, {MCMC}", journal = "Neural Computation", volume = "", editor = "", number = "", publisher = "", url = "http://www2.compute.dtu.dk/pubdb/pubs/4750-full.html", abstract = "Non-linear hemodynamic models express the {BOLD} signal as a non- linear, parametric functional of the temporal sequence of local neural ac- tivity. Several models have been proposed both for the neural activity and the hemodynamics. We compare two such combined models: the 'original' balloon model with a square-pulse neural model [5], and an ex- tended balloon model with a more sophisticated neural model [3]. We learn the parameters of both models using a Bayesian approach, where the distribution of the parameters conditioned on the data is estimated using Markov chain Monte Carlo techniques. Using a split-half resampling procedure [14], we compare the generalization abilities of the models as well as their reproducibility, both for synthetic and real data, recorded from two diŽerent visual stimulation paradigms. The results show that the simple model is the best one for these data." }