Dear SPM experts,
I have experimental data that I need to analyze and I wanted to ask you to review if my plan of analysis is correct because I'm not confident if it is the optimal way to analyze the data.
The experiment aim is to check the difference in activation patterns during a choice-task between 2 subjects groups in 3 experimental conditions (2 manipulations and 1 control).
Each trial starts by presenting 6sec choice-task, then subjects have 2sec to made their decision in the task by clicking a button and lastly 4-8s of fixation (our jitter) before the next trial.
We only have a single run which composed of 72 (randomized in order) of the mentioned (consisting 3 types of our choice-task).
Our TR=2.7sec and the ITI=4-8sec.
For the 1st level analysis, in an event related design where each period of the choice-tasks (6s) is considered a single event , my aim is to convolve the hrf with the choice-task periods to see the brain activations. I plan to create 3 conditions (A,B,C) by entering the onsets of the 3 types of choice-task events we have.
However, due to our long TR I'm not sure if this way is good enough for modeling the neural response? I mean, shouldn't I need to change the high-pass filter or employ a slice-timing correction? Or maybe you have a more accurate way to enter the onsets (maybe with a shift of a few seconds)?
Thank you very much in advance and Merry Christmas,