These demonstrations illustrate the behaviour of mean-field and neural mass models of cortical sources through simulations and stability analyses. These models are exactly the same models used in DCM for evoked, induced and steady-state responses. It is anticipated that people will deconstruct the code after viewing the demos, to understand the nature of the models in more depth and how they are specified, integrated and used. Many of the figures produced are in the peer reviewed articles associated with each demonstration.
 
Although MEG/EEG signals are highly variable, systematic changes in distinct frequency bands are commonly encountered. These frequency-specific changes represent robust neural correlates of cognitive or perceptual processes (for example, alpha rhythms emerge on closing the eyes). However, their functional significance remains a matter of debate. Some of the mechanisms that generate these signals are known at the cellular level and rest on a balance of excitatory and inhibitory interactions within and between populations of neurons. The kinetics of the ensuing population dynamics determine the frequency of oscillations. In these demonstrations we extend the classical nonlinear lumped-parameter model of alpha rhythms, initially developed by Lopes da Silva and colleagues, to generate more complex dynamics and consider conduction based models.
 
R. Moran, S.J. Kiebel, N. Rombach, W.T. O'Connor, K.J. Murphy, R.B. Reilly, and K.J. Friston. Bayesian estimation of synaptic physiology from the spectral responses of neural masses. NeuroImage, 42(1):272-284, 2008.
 
These descriptions of the new features are taken from the SPM8 Release Notes
 
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