Dear experts,
I have a dataset in which the events of interest are 7 second film clips, each immediately followed by a 7-second rating scale. A fixation cross appears for 2-4-6- or 8 seconds before each new film clip. I have three types of film clips, presented in pseudo-random order.
I modeled the data in the following way : I entered one regressor for each type of film clip, one regressor for all the rating scales, and one regressor for each movement parameter (from realignment).
I have two questions :
1) If I only compare activation to the different types of film clips, will the absence of an ISI between each clip and the following rating scale be a problem?
2) I have a 2-sec TR, so each film clip’s onset is at the beginning of a TR. I know this would be problematic if this were an event-related design, but is this a problem in this case, given that each « event » has a duration of 7 seconds?
Thanks for your help!
Fanny
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