ASR burst criterion default threshold

[d-scanzi]

Hi there,

In our lab we noticed that there is a discrepancy between the ASR default cutoff and the suggested "conservative" criterion reported in the README. Currently, the default criterion is set to 5 SD, but the one suggested is 10.

A cutoff of 5 is very aggressive, and there is evidence that a value at least greater than 10 should be used to obtain a sensible reduction of artifacts without losing too much information (Chang at al., 2018, also referenced in the wiki section of this repository).

Currently, the README file states:

For new users it is recommended to first visually inspect the difference between the aw and the cleaned data (using eegplot) to get a sense of the content the is removed at various levels of this input variable. Here, a quite conservative value is 10; this is the current default value.

This might throw off some users if they do not keep attention at the actual cut off.

Suggestions

• Set the default value for ASR at 10. Possibly even higher (maybe 20) to stay on the conservative side. As for the paper reported above, a cutoff of 10 would potentially modify just under 60% of the data.
• Modify the help text of the functions that uses ASR (clean_rawdata, clean_asr, clean_artifacts) as they currently report the following: For new users it is recommended to at first visually inspect the difference between the original and cleaned data to get a sense of the removed content at various levels. A quite conservative value is 5. Default: 5. This might be another source of confusion, as 5 is said to be a conservative default, while it is actually aggressive. This help text should be updated independently of whether the default parameter is modified.

[arnodelorme]

Actually, the new default in the GUI is 20. I have updated the README file accordingly, as well as all the MATLAB files. 5 is an aggressive value and 20 is a conservative value.

[d-scanzi]

Thank you @arnodelorme!

Just for completeness, asr_calibrate and asr_calibrate_r have the same help text (sorry I just noticed now), so you might want to update those too.

Thanks again