Analyzing MEG data in FieldTrip
A much more thorough and complete guide can be found at http://fieldtrip.fcdonders.nl/tutorial. This is intended to give people who haven't used FieldTrip at all an overall feel for how data is structured and analyses are conducted.
How FieldTrip compares to SPM
Like SPM, FieldTrip is written in Matlab. Unlike SPM, there is no graphical interface for conducting analyses; everything is done through scripts. This provides a great deal of flexibility, and the ability to always be able to see exactly what analyses were run. However, it does take a bit of knowledge of Matlab (but not too much).
(SPM now includes a distribution of FieldTrip, so many of the "behind the scenes" analyses are identical.)
Because FieldTrip functions are written in Matlab, to get help on any function you can type "help <function>" in Matlab, or "edit <function>" to view the source (and help). It's a good habit to get into to look at the help for every function you use.
Matlab structures
Most FieldTrip functions take as one of their arguments a configuration (cfg) structure. A structure is a Matlab variable that contains one or more fields, and each field can then in turn contain a type of information. A
Starting FieldTrip