= Analysis of MEG Data in SPM5 = Many of us here use SPM for EEG and/or MEG analysis. The main reason is that SPM is freeware (requiring only Matlab), and thus modifiable and relatively easily to understand (if you have basic knowledge of a procedural computer language, given that Matlab is a fairly high-level language). Several of us are actively extending SPM for our own purposes, particularly in relation to the Neuromag type of MEG data. ---- * For specific demo using data from our Neuromag MEG machine, see SpmDemo * For a fuller demo of other EEG/MEG analysis in SPM5 (though from a different MEG machine), including more general features (e.g, time-freq analysis, 3D statistical maps), with proper step-by-step instructions via the GUI, see: http://www.fil.ion.ucl.ac.uk/spm/data/mmfaces.html * For a more theoretical introduction to source localisation in SPM5, see these slides: attachment:henson-SPM-Grad08-4-meeg.ppt ---- Here are some relevant papers: * Summary of localisation approach using ReML for evoked and induced responses (mathematical; cites earlier development papers too): attachment:FristonEtAl_hbm_06.pdf * Basic considerations for Group Analyses (though using individual meshes): attachment:HensonEtAl_NI_07.pdf * Use of inverse-normalised ("canonical") cortical meshes: attachment:MattoutEtAl_JCIN_07.pdf * Choice of forward models for MEG (e.g, single-sphere vs BEM), including further validation of canonical meshes: attachment:HensonEtAl_NI_inpress.pdf * '''New method of Multiple Sparse Priors (MSP): attachment:FristonEtAl_NI_08_MSP.pdf''' ---- Additional SPM5 functions: * If you are not using the version of SPM5 installed on the CBU network (ie do not have */spm5/cbu_updates on your Matlab path) - eg are an external collaborator - you will need to download the latest versions of some site-specific SPM5 functions in order to read the FIF format data files from our MEG scanner. These SPM functions can be downloaded from here: http://imaging.mrc-cbu.cam.ac.uk/svn/spm5_cbu_updates/devel (see also http://www.mrc-cbu.cam.ac.uk/~rh01/fif2spm.html). * Miscellaneous helpful SPM/Matlab functions we've written can be found here: http://imaging.mrc-cbu.cam.ac.uk/svn/meg_misc/devel/ For permission to contribute to or edit this repository, contact Ian Nimmo-Smith. * A meta-toolbox of functions that allow you to apply EEGLAB functions (eg. ICA, plot raw data, plot ERFimage) to SPM-format MEG data can be found here: http://imaging.mrc-cbu.cam.ac.uk/svn/spmeeglab/devel/ For further information, contact Jason Taylor. Help on artefact correction using ICA is forthcoming... * This page describes the procedure for creating a 3D SensorSpm (topography x time). ---- General note: * SPM5 can read raw and averaged FIF files, though you will probably first want to run your raw data through the [:Maxfilter:Maxfilter utility], particularly if you 1) used Active Shielding during acquisition, 2) if you want to apply (temporal) SSS to remove noise, 3) if you used continuous HPI and/or 4) if you want to transform all subjects to a common (device) space. Max Filter can also downsample (eg from 1000Hz to 200Hz) and convert the data into different datatypes (e.g, short), which will help reduce filesize and processing time.