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Dear SPM Experts, I am currently working on designing a task and I am concerned that when we reach the preprocessing step our high-pass filter will filter out the signal from our condition of interest causing us to lose power. Our task consists of 6 scanner runs. Trial types are the same across all runs; however, 3 of our runs will have a mood-induction component while the other 3 runs do not. Within each of these runs we have further broken down the trials into 6 “mini blocks”, meaning we present trials (all trials are jittered) in 6 blocks of approximately 45 sec for each block, with a 10 second rest between each “mini blocks”, for a total of 330 sec per run. These runs will be randomized and counterbalanced across participants. We are worried that the runs containing the sustained mood effect, will have that effect over the course of the run. Since the effect will have a duration greater then that of the standard high-pass filter window, will that filtering cause us to lose power? Are our concerns about the high-pass filter valid and do you have any suggestions on how we could design our task and still give the mood we are trying to induce time to build up? Any comments or suggestions are welcomed. Thank you! Stefania