Thank you for your response, Helmut. For the case of longer events, how
could I investigated the corresponded canonical HRF functions given that I
also have a design matrix that model the canonical HRF?
Thanks,
Drew
On 5/13/14 9:46 AM, "Helmut Nebl"
<[log in to unmask]> wrote:
>Dear Drew,
>
>
>the idea is to cover the time period in which you still expect some
>deviation from baseline, at least in theory, which you would like to
>control for. For short stimuli this results in a length similar to the
>canonical HRF, so something like 25 - 30 s. If you use longer events,
>this might take (much) longer. In that case you could look at the
>corresponding boxcar functions convolved with the canonical HRF to get an
>impression of the expected "default" time course. Depending on the
>outcome you might then go with a longer time period for the FIR models as
>well.
>
>
>Hope this helps a little,
>
>Helmut
>
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