 |
 |
dear spmer. a few weeks ago there was a question about a paradigm with scan pauses. i could not find any reply to this (neither could i find something in the archives). i have to ask almost the same question due to a paradigm, which needs scan pauses (due to the noise of the scanner). we explored the following paradigm: 60 scans baseline - 5 min pause with sensoric testing- 108 scans stimulation - 15 min pause with sensoric testing - 60 scans - 15 min pause with sensoric testing - 60 scans. we want to answer the BOLD-signal changes after the stimulation over a tine period of 50 minutes. now we have to face the problem of the interruption of the time series. here my questions: 1. is it absolutely impossible to conduct a paradigm with scanning pause (and why)? 2. is there a time limit of the pause which would be tolerable? 3. is there any method, how we can test, whether the pause is really a problem or not (and not just theoretical)? 4. can we do something to solve this problem (like correction for global changes)? 5. if we have to regard the 4 blocks as individual sessions, is it possible to use the first session (baseline) as the baseline condition and contrast all the other sessions with it? i would appreciate any commend about this very much (and even more, if it is not to technical). thanks a lot markus