Dear all,

I am conducting a fMRI study (event-related design) in old adults. As I understand, aging can induce changes in latency and amplitude of the haemodinamuc response (that´s right?).

Taking into account this, I was wondering if it is a good choice uses the Canonical HRF with time and dispersion derivatives in my first level. More generally speaking, in which cases is it advisable to include derivatives?

Thank you in advance.

Best regards,

Steve.