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