The MVB facility allows one to compare different hypotheses about the mapping from functional or structural anatomy to perceptual and behavioural consequences. Typical use would be to infer whether a local cortical representation is sparse or distributed. The aim of MVB is not to predict brain states or classify outcomes (because these will be known) but to enable inference on different models of structure–function mappings. This allows one to optimise the model itself and produce predictions that outperform standard pattern classification approaches, like support vector machines.

K.J. Friston, C. Chu, Janaina Mourão-Miranda, Oliver Hulme, G. Rees, W.D. Penny, and J. Ashburner. Bayesian decoding of brain images. NeuroImage, 39(1):181-205, 2008.
 
These descriptions of the new features are taken from the SPM8 Release Notes
 
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