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

  FT_WRITE_CIFTI writes functional data or functional connectivity to a cifti-2
  file. The geometrical description of the brainordinates can consist of
  triangulated surfaces or voxels in a regular 3-D volumetric grid. The functional
  data can consist of a dense or a parcellated representation. Furthermore, it
  writes the geometrical description of the surfaces to one or multiple gifti
  files.
 
  Use as
    ft_write_cifti(filename, data, ...)
  where the filename is a string and the data according to the description below.
 
  If the input data describes a dense representation of functional data, the data
  structure should conform to the FT_DATATYPE_SOURCE or FT_DATATYPE_VOLUME
  definition.
 
  If the input data describes a parcellated representation of functional data, the
  data structure should conform to the FT_DATATYPE_TIMELOCK or FT_DATATYPE_FREQ
  definition. In addition, the description of the geometry should be specified in
  the data.brainordinate field, which should conform to the FT_DATATYPE_SOURCE or
  FT_DATATYPE_VOLUME definition.
 
  Any optional input arguments should come in key-value pairs and may include
    'parameter'        = string, fieldname that contains the functional data
    'brainstructure'   = string, fieldname that describes the brain structures (default = 'brainstructure')
    'parcellation'     = string, fieldname that describes the parcellation (default = 'parcellation')
    'precision'        = string, can be 'single', 'double', 'int32', etc. (default ='single')
    'writesurface'     = boolean, can be false or true (default = true)
    'debug'            = boolean, write a debug.xml file (default = false)
 
  The brainstructure refers to the global anatomical structure, such as CortexLeft, Thalamus, etc.
  The parcellation refers to the the detailled parcellation, such as BA1, BA2, BA3, etc.
 
  See also FT_READ_CIFTI, FT_READ_MRI, FT_WRITE_MRI