Hi Ali,
Jumping in for more fun...
1) Gang's suggestion of 3dDeconvolve or 3dfim+ can get you p-values,
or you could run cdf yourself. For example, if a time series of length 100
yields a correlation of 0.3, then the p-value might be 0.002426, from:
cdf -t2p fico .3 100 1 1
That assumes only demeaning the data (as is done with 3dTcorr1D).
If quadratic detrending were done, the ort-dof would be 3, leading to
a p-value of 0.00269, from:
cdf -t2p fico .3 100 1 3
See the output of "cdf -help" for details.
2) 3dTcorr1D removes the mean, but does no trend removal.
- rick