Reconstructing MEG Sources with Unknown Correlations

Part of Advances in Neural Information Processing Systems 16 (NIPS 2003)

Bibtex Metadata Paper


Maneesh Sahani, Srikantan Nagarajan


Existing source location and recovery algorithms used in magnetoen- cephalographic imaging generally assume that the source activity at dif- ferent brain locations is independent or that the correlation structure is known. However, electrophysiological recordings of local field poten- tials show strong correlations in aggregate activity over significant dis- tances. Indeed, it seems very likely that stimulus-evoked activity would follow strongly correlated time-courses in different brain areas. Here, we present, and validate through simulations, a new approach to source reconstruction in which the correlation between sources is modelled and estimated explicitly by variational Bayesian methods, facilitating accu- rate recovery of source locations and the time-courses of their activation.