FieldTrip

Note that this reference documentation is identical to the help that is displayed in Matlab when you type “help ft_prepare_headmodel”.

  FT_PREPARE_HEADMODEL constructs a volume conduction model from
  the geometry of the head. The volume conduction model specifies how
  currents that are generated by sources in the brain, e.g. dipoles,
  are propagated through the tissue and how these result in externally
  measureable EEG potentials or MEG fields.
 
  FieldTrip implements a variety of forward solutions, some of them using
  external toolboxes or executables. Each of the forward solutions requires
  a set of configuration options which are listed below. This function
  takes care of all the preparatory steps in the construction of the volume
  conduction model and sets it up so that subsequent computations are
  efficient and fast.
 
  For EEG the following methods are available
    singlesphere
    asa
    bemcp
    dipoli
    openmeeg
    concentricspheres
    halfspace
    infinite
    infinite_slab
 
  For MEG the following methods are available
    singlesphere
    localspheres
    singleshell
    infinite
 
  Use as
    vol = ft_prepare_headmodel(cfg)
    vol = ft_prepare_headmodel(cfg, vol)
    vol = ft_prepare_headmodel(cfg, bnd)
    vol = ft_prepare_headmodel(cfg, elec)
  
  In general the input to this function is a geometrical description of the
  shape of the head and a description of the electrical conductivity. The
  second input argument (vol or bnd) can be a surface mesh that was
  obtained from FT_PREPARE_MESH or a segmented anatomical MRI that was
  obtained from FT_VOLUMESEGMENT. If the mesh is stored on disk, it can be
  provided as filename in cfg.hdmfile.
 
  The configuration structure should contain:
      cfg.method            string that specifies the forward solution, see below
      cfg.conductivity      a number or a vector containing the conductivities
                            of the compartments
  
  Additionally, the specific methods each have their specific configuration 
  options that are listed below.
  
  BEMCP, DIPOLI, OPENMEEG
      cfg.isolatedsource    (optional)
  
  CONCENTRICSPHERES
      cfg.fitind            (optional)
  
  LOCALSPHERES
      cfg.grad   
      cfg.feedback          (optional)
      cfg.radius            (optional)
      cfg.maxradius         (optional)
      cfg.baseline          (optional)
  
  HALFSPACE
      cfg.point     
      cfg.submethod         (optional)
      
  SIMBIO, FNS
      cfg.tissue      
      cfg.tissueval 
      cfg.tissuecond  
      cfg.sens      
      cfg.transform   
      cfg.unit      
  
  INFINITE_SLAB
      cfg.samplepoint
      cfg.conductivity
 
  See also FT_PREPARE_MESH, FT_VOLUMESEGMENT, FT_VOLUMEREALIGN, FT_FETCH_SENS