Hi Sally,
So you expect a quadratic fluctuation of the betas corresponding to some external behavioral parameter? If that is true, this might be more easily solved using amplitude modulation in 3dDeconvolve/3dREMLfit. You could add linear and quadratic modulators (using Legendre polynomials) to the stimulus times, and the result would be 3 betas, for the mean, linear and quadratic magnitudes. That would be more straightforward than trying to implement something in 3dNLfim.
Does that seem like a reasonable option?
- rick
