Hello, experts.
I have one structural image and two functional images, each corresponding to a different experiment (resting-state and task-based). I would like to ask about the preprocessing of these data in CONN. How should I do it in CONN? Should I perform separate preprocessing for each functional image (paradigm), or should I perform it together in one preprocessing but create two conditions or sessions? I just want to ensure that I handle the process accurately. Any guidance or insights would be greatly appreciated.
Thank you!
Hi,
Both approaches are perfectly fine. I would probably recommend including both runs in the same CONN project, preprocessing them jointly, and then defining different conditions (in Setup.conditions) each focusing on different aspects of your resting-state or task-based data. The main advantage of this approach is that it will allow you to define analyses that span both experiments, and it will ensure the exact same preprocessing steps across the two experiments so that there are no artifactual differences between them that could be introduced by having different preprocessing pipelines.
There is only one minor added complexity when including both rest- and task- analyses in the same project, which arises from often prefering to apply different frequency-filters to the data during denoising for resting state analyses (where we typically choose a band-pass filter like 0.01 - 0.10 Hz) compared to task-based analyses (where we typically choose a high-pass filter like 0.01 - inf Hz). Rather than running denoising twice with different frequency filters, which may be cumbersome, the simplest way to do this in CONN is to define condition-specific filters. For example, if you define a 'rest' condition that is focusing on the resting-state session, you can select 'fixed band-pass filter' (under 'time-frequency decomposition' in the Setup.conditions tab) and enter there a [0.01 0.10] filter, and then if you define a 'taskA' condition that is focusing on your task-based session you would also select 'fixed band-pass filter' but enter there a [0.01 inf] filter. Once you have explicitly defined filters for all of your conditions you can then simply remove in the Denoising tab any additional filter (e.g. just enter [0 inf] values there), and CONN will apply the appropriate filter to the data during denoising specific to each condition.
Hope this helps
Alfonso
Originally posted by Ric John Ombid:
Hello, experts.
I have one structural image and two functional images, each corresponding to a different experiment (resting-state and task-based). I would like to ask about the preprocessing of these data in CONN. How should I do it in CONN? Should I perform separate preprocessing for each functional image (paradigm), or should I perform it together in one preprocessing but create two conditions or sessions? I just want to ensure that I handle the process accurately. Any guidance or insights would be greatly appreciated.
Thank you!