[Eeglablist] Three EEGLAB questions
Giovanni Santostasi
gsantostasi at gmail.com
Mon Sep 30 13:00:29 PDT 2013
Here some simple code you could use (independently of EEGlab):
Suppose EEG1 is time series 1 and EEG2 is time series 2, also supposed you
want to compare phase coherence in the delta band (you can change this for
any band you want):
.....
samp_f=500; % sampling frequency
wd=[0.5 4]/(samp_f/2); % filter setting for delta band, 0.5-4 Hz
[b,a]=butter(4,wd); % butter filter
FEEG1=filtfilt(b,a,EEG1); % filtering time series 1
FEEG2=filtfilt(b,a,EEG2); % filtering time series 2
PhaseEEG1=angle(hilbert(FEEG1))+pi;% phase for EEG1
PhaseEEG2=angle(hilbert(FEEG2))+pi;% phase for EEG2
PhasePD=(PhaseEEG1-PhaseEEG2)./PhaseEEG2*100; % percentage difference
% between EEG1 and EEG2 relative to EEG2 phase.
PhasePD would be another time series with same sampling frequency of EEG1
and EEG2 and it would give you a simple measure of the phase coherence
between the two series.
Giovanni
On Sat, Sep 28, 2013 at 9:38 PM, Fred Travis <ftravis at mum.edu> wrote:
> Thank you Robert.
>
> As you know, there is a growing body of work on synchrony. How can I
> calculate that in EEGLAB?
>
> Fred
>
> On 9/27/2013 8:21 PM, robert coben wrote:
>
> Fred and Arnaud,
>
> Having worked with coherence and more recently sloreta coherence and
> SIFT, I will provide some feedback. Coherence as a measure of
> "connectivity" between pairs is extremely flawed. I would agree with Arnaud
> is recommending SIFT and granger causality. The information is much richer
> and more closely resembles structural connectivity metrics.
>
> Rob
>
>
> On Sep 27, 2013, at 5:38 PM, Fred Travis <ftravis at mum.edu> wrote:
>
> Hi Arnaud
>
> By synchrony I mean in phase EEG. Coherence us a general case-stability
> of phase relation--and synchrony is a specific case--stability of phase
> relation and in phase
>
> Fred
> On 9/27/2013 2:54 PM, Arnaud Delorme wrote:
>
> Hi Fred,
>
> what do you mean by synchrony?
> To caclulate some of additional connectivity measures, you might want to
> try SIFT, an EEGLAB associated toolbox and plugin. It will allow you to
> compute Granger Causality based measures such as partial directed
> coherence. It will also allow you to compute many other measures including
> the popular directed transfer entropy.
>
> Hope this helps,
>
> Arno
>
>
> 1. synchrony (rather than coherence)
>
> 2. cross frequency coherence--coherence between frequency bands (Palva
> and Palva)
> 3. cepstrum analysis--frequency analysis of the power spectra
>
> Many thanks
>
> Fred
>
> --
> Fred Travis, Ph.D.
> Director, Center for Brain, Consciousness and Cognition
> Dean, Graduate School
> Chair, Maharishi Vedic Science Department
> Office: 641 472 1209
> Fax: 641 470 1316
> Skype: fredtravis
> Website: drfredtravis.com
>
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>
>
>
> --
> Fred Travis, Ph.D.
> Director, Center for Brain, Consciousness and Cognition
> Dean, Graduate School
> Chair, Maharishi Vedic Science Department
> Office: 641 472 1209
> Fax: 641 470 1316
> Skype: fredtravis
> Website: drfredtravis.com
>
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>
>
>
> --
> Fred Travis, Ph.D.
> Director, Center for Brain, Consciousness and Cognition
> Dean, Graduate School
> Chair, Maharishi Vedic Science Department
> Office: 641 472 1209
> Fax: 641 470 1316
> Skype: fredtravis
> Website: drfredtravis.com
>
>
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20130930/54cca10b/attachment.html>
More information about the eeglablist
mailing list