FT_GLOBALMEANFIELD
Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_globalmeanfield”.
FT_GLOBALMEANFIELD calculates global mean field amplitude or power of input data Use as [gmf] = ft_globalmeanfield(cfg, data) The data should be organised in a structure as obtained from the FT_TIMELOCKANALYSIS function. The configuration should be according to FT_PREPROCESSING function. The configuration should be according to cfg.method = string, determines whether the amplitude or power should be calculated (see below, default is 'amplitude', can be 'power') cfg.channel = Nx1 cell-array with selection of channels (default = 'all'), see FT_CHANNELSELECTION for details This function calculates the global mean field power, or amplitude, as described in: Lehmann D, Skrandies W. Reference-free identification of components of checkerboard-evoked multichannel potential fields. Electroencephalogr Clin Neurophysiol. 1980 Jun;48(6):609-21. PubMed PMID: 6155251. Please note that to calculate what is clasically referred to as Global Mean Field Power, cfg.method must be 'amplitude'. The naming implies a squared measure but this is not the case. To facilitate data-handling and distributed computing you can use cfg.inputfile = ... cfg.outputfile = ... If you specify one of these (or both) the input data will be read from a *.mat file on disk and/or the output data will be written to a *.mat file. These mat files should contain only a single variable, corresponding with the input/output structure. See also FT_TIMELOCKANALYSIS