[FieldTrip] Jump artifacts not detected

Lam, N.H.L. (Nietzsche) n.lam at donders.ru.nl
Fri Jul 10 15:17:53 CEST 2015

Hey Mats,

the "old" refers to you calling ft_artifact_zvalue_old, instead of ft_artifact_zvalue, which is also the function used in the FT tutorial.   There are likely to be various differences between the 'old', and current code, perhaps this explains why the jumps aren't being detected.


From: fieldtrip-bounces at science.ru.nl [fieldtrip-bounces at science.ru.nl] on behalf of Es, M.W.J. van (Mats) [M.vanEs at donders.ru.nl]
Sent: 10 July 2015 14:19
To: fieldtrip at science.ru.nl
Subject: Re: [FieldTrip] Jump artifacts not detected

Hi Jan Matthijs,

I do not think that the problem lies in the size of the jump: when I artificially create a very large jump in my data the jump is also not detected, see code.

data_short.trial{1}(132,1:700)=0; %channel 132 is MRC11
data_short.trial{1}(132,701:1441)=1; %data 'jumps' up to 1 and stays there (massively bigger jump than actual squid jump).
You are right that if the 'muscle' algorithm picks up the jump, there is no problem. However, I don't know if this algorithm picks up the jumps consistently. (I did find 10 jumps in one dataset and zero in another, which I know is plausible but still).

About my code: could you refer me to the newer version of the code? The code I use was on the fieldtrip tutorial (http://www.fieldtriptoolbox.org/tutorial/automatic_artifact_rejection).

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20150710/71112a84/attachment-0002.html>

More information about the fieldtrip mailing list