biostudies-literatureStevenson CMRC UK MEG Partnership GrantLeverhulme Trust Early Career FellowshipJ Jacob Astor Charitable TrustMedical Research CouncilWellcome TrustMRC89-95https://www.ebi.ac.uk/biostudies/studies/S-EPMC4073649biostudies-literatureUnknown94There are now a number of non-invasive methods to image human brain function in-vivo. However, the accuracy of these images remains unknown and can currently only be estimated through the use of invasive recordings to generate a functional ground truth. Neuronal activity follows grey matter structure and accurate estimates of neuronal activity will have stronger support from accurate generative models of anatomy. Here we introduce a general framework that, for the first time, enables the spatial distortion of a functional brain image to be estimated empirically. We use a spherical harmonic decomposition to modulate each cortical hemisphere from its original form towards progressively simpler structures, ending in an ellipsoid. Functional estimates that are not supported by the simpler cortNeuroImageDoes function fit structure? A ground truth for non-invasive neuroimaging.PMC4073649MR/K005464/1091593MC_US_A060_0046MC_U105579226Stevenson CBarnes GMorris PHenson RTroebinger LPenny WLopez JDMattout JBrookes MHillebrand AfalseDoes function fit structure? A ground truth for non-invasive neuroimaging.There are now a number of non-invasive methods to image human brain function in-vivo. However, the accuracy of these images remains unknown and can currently only be estimated through the use of invasive recordings to generate a functional ground truth. Neuronal activity follows grey matter structure and accurate estimates of neuronal activity will have stronger support from accurate generative models of anatomy. Here we introduce a general framework that, for the first time, enables the spatial distortion of a functional brain image to be estimated empirically. We use a spherical harmonic decomposition to modulate each cortical hemisphere from its original form towards progressively simpler structures, ending in an ellipsoid. Functional estimates that are not supported by the simpler cort2014-01-01T00:00:00Z2014 Jul2025-06-01T00:33:01.083Z2025-06-01T00:33:01.083ZS-EPMC40736492463688010.1016/j.neuroimage.2014.02.033