canlab / CanlabCore

Core tools required for running Canlab Matlab toolboxes. The heart of this toolbox is object-oriented tools that enable interactive analysis of neuroimaging data and simple scripts using high-level commands tailored to neuroimaging analysis.
https://canlab.github.io/CanlabCore/
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Default MADs threshold in scn_session_spike_id #23

Open teresabertram opened 6 years ago

teresabertram commented 6 years ago

Dear Canlab group, thank you for this great toolbox! I am using your scn_session_spike_id function and it works very nicely. However, using the default MADs value of 10, quite many of my volumes are identified as containing spikes (up to 10 % from one session). This made me wonder what your rationale was for setting this default threshold? I first thought that I could simply find the correct threshold by determining the critical chi-square value for a desired probability level and the degrees of freedom. Then I saw that in your function the MADs threshold is not applied directly to the calculated mahalanobis distances in d2 (I guess given the degrees of freedom it would also have to be much higher than 10 in this case anyways) but rather as a cutoff for deviation of these d2 values from a moving average. Can you give a recommendation what criteria to use if one wants to change the default MADs value?

Many thanks in advance!

Teresa