SPM/PPI

= Psychophysiological Interactions (PPI) =


 * http://www.fil.ion.ucl.ac.uk/spm/doc/biblio/Keyword/PPI.html
 * http://www.fil.ion.ucl.ac.uk/spm/data/attention/#PPI
 * http://scan.oxfordjournals.org/content/7/5/604.full
 * http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/PPI