Hello all,
I have a question regarding degrees of freedom. For a single run
single subject t-test, isn't the degrees of freedom equal to the
number of time samples (brain volumes) acquired during the fMRI run
MINUS the number of regressors used in the design matrix (including
the number of regressors used to low pass filter the data)? What is
the difference between the degrees of freedom and effective degrees of
freedom?
Does anyone know of a good reference to consult regarding degrees
of freedom calculations in t-tests and F-tests for fMRI analyses?
Hopefully these references will contain formulae for calculating the
degrees of freedom for a t-test and F-test?
Thanks
Todd Penney
|