Lab Manual:AFNI
From SpanLabWiki
polort rule of thumb[edit]
AFNI folks suggest that for every 150 seconds you should add a degree to the polynomial.
For a 150 second long scan, you would use -polort 1, for a 300 second scan, you would use -polort 2, and so forth.
3dRegAna[edit]
3dRegAna is an AFNI program which can be used to do multiple linear analysis
-model tag[edit]
The -model tag can be used to specifiy and test regression models
-model 1 : 0
will test Yi = B0 + B1X1i+ei vs. Yi = B0 + ei
-model 2 : 0
will test Yi = B0 + B2X2i+ei vs. Yi = B0 + ei
-model 2 : 1 0
will test Yi = B0 + B1X1i + B2X2i+ei vs. Yi = B0+ B1X1i + ei
-model 2 1 : 0
will test Yi = B0 + B1X1i + B2X2i+ei vs. Yi = B0+ei
