Hello,
I have been looking at the basis functions in SPM2 (SPM.xBF.bf) and it
seems that the intensity, i.e. max height of the temporal derivatives is
relatively small compared to the canonical HRF. It seems that this is not
true for SPM99. I suspect that it may not matter much, as one never
compares the parameter estimates of the derivatives with the canonical
anyway, but out of curiosity, may someone tell me why is there such a
change in the new version (if indeed there is any)?
Many thanks,
Hakwan
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