Dear all,

I have been trying to use ArtRepair and I have some questions regarding the preprocessing I am doing, and I would be very grateful if you could answer some of them. The preprocessing I am doing is as follows:

1. “art_slice”: Normally the threshold has to be modified until it is inferior to 5%.

- IS IT OKAY IF THE THRESHOLDS ARE DIFFERENT FOR DIFFERENT PARTICIPANTS?

- WHAT TO DO IF THE MASK CREATED IS NOT ACCURATE (THERE SEEMS TO BE DATA OUTSIDE THE HEAD)?

2. Slice timing

3. Realign & reslice

(4). art_despike IF “visual inspection of the ArtGlobal figure uncovers greater than +/-1 % drift in the mean global signal across the entire time series”.

- IS THERE A WAY TO CALCULATE THE PERCENTAGE OF THE SIGNAL DRIFT IN ORDER TO CHECK IF IT’S GREATER THAN +/-1 %? (For example by calculating the % of decrease between the maximum and the minimum value OR the first and the last image?

5. Coregistration

6. Segmentation

7. Normalization

8. Smoothing

(9). art_global: apply if art_despike was not applied.

When using art_global, users are asked “always repairs 1st scan of each?”. IF I ALREADY DELETED THE TWO FIRST DUMMY SCANS, SHOULD I REPLY “YES” OR “NO”?

- IF THERE IS TOO MUCH MOTION, IS IT OKAY TO SKIP “art_motionregress” AND USE THE “.rp” FILE FROM THE REALIGMENT STEP AS MOTION REGRESSORS?

- WHEN USING MOTION REGRESSORS, IS IT BETTER TO LEAVE THE SCAN-TO-SCAN MOVEMENT THRESHOLD AT 0.5 mm/TR?

- IS IT A PROBLEM IF ART_DESPIKE IS PERFORMED FOR SOME PARTICIPANTS AND ART_GLOBAL FOR OTHERS?

Finally, I would like to know if you believe the preprocessing I described is correct or not.

I would be extremely grateful if any of you could answer to these questions, it would be very helpful!

Best,

Ariadna