Decide the duration of the hemodynamic response first, and then figure out the number of basis functions based on your TR length and the HDR duration you would like to cover. Since there is a stimulus at 13s within each trial, you may consider covering the HDR for at least 25s. The ITI is important when you design the experiment, but not crucial when you specify the HDR duration in modeling.
Gang
Edited 1 time(s). Last edit at 10/17/2014 01:44PM by Gang.