<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt">I have a related question. I am extraction frequency bins of 3-5 Hz, 6-9
Hz and 10-13 Hz (using FIR). I would like to extract the band power and
mean band power for selected channels (I have already selected the
channels using select data option). So, basically I would like to
extract all selected channel powers (33 in my case) and mean band
powers. I tried to use spectopo(); however, it gives parsing error. <br>My
understanding is that in order to use pwelch and spec I need to extract
the preprocessed data in .mat format. Is there any other way to
calculate channel powers and mean powers ? <br>Thanks in advance<br>Meltem<div><span></span></div><div><br></div> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div dir="ltr"> <font face="Arial" size="2"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> Simon-Shlomo Poil <simonshlomo.poil@cncr.vu.nl><br> <b><span style="font-weight: bold;">To:</span></b> "Achim, André" <achim.andre@uqam.ca> <br><b><span style="font-weight: bold;">Cc:</span></b> "eeglablist@sccn.ucsd.edu" <eeglablist@sccn.ucsd.edu>; "Poil, S.S." <s.s.poil@vu.nl> <br> <b><span style="font-weight: bold;">Sent:</span></b> Monday, June 20, 2011 4:42 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [Eeglablist] Alpha power spectrum assymetry<br> </font> </div> <br>ups. yes. that's true..<br><br>I would btw.
also recommend to use 'pwelch' or 'spec' directly.<br><br>-Simon<br><br>2011/6/20 Achim, André <<a ymailto="mailto:achim.andre@uqam.ca" href="mailto:achim.andre@uqam.ca">achim.andre@uqam.ca</a>>:<br>> The code below "spectra(1, find(freqs >= 8 | freqs <=13))" uses | (or) instead of & (and), which would return all available frequencies. Besides, the "find" is not necessary; it would be more efficient to write: "spectra(1, freqs >= 8 & freqs <=13)"<br>><br>> André Achim<br>><br>> -----Message d'origine-----<br>> De : <a ymailto="mailto:eeglablist-bounces@sccn.ucsd.edu" href="mailto:eeglablist-bounces@sccn.ucsd.edu">eeglablist-bounces@sccn.ucsd.edu</a> [mailto:<a ymailto="mailto:eeglablist-bounces@sccn.ucsd.edu" href="mailto:eeglablist-bounces@sccn.ucsd.edu">eeglablist-bounces@sccn.ucsd.edu</a>] De la part de Simon-Shlomo Poil<br>> Envoyé : 19 juin 2011 16:12<br>> À : nikos dhmou; <a
ymailto="mailto:eeglablist@sccn.ucsd.edu" href="mailto:eeglablist@sccn.ucsd.edu">eeglablist@sccn.ucsd.edu</a><br>> Objet : Re: [Eeglablist] Alpha power spectrum assymetry<br>><br>> Hi Nikos,<br>><br>> The output of spectopo is<br>> Outputs:<br>> % spectra = (nchans,nfreqs) power spectra (mean power over<br>> epochs), in dB<br>> % freqs = frequencies of spectra (Hz)<br>><br>> i.e.<br>><br>> [spectra, freqs] = spectopo(..<br>><br>> will give you the spectra with the corresponding frequencies<br>><br>> spectra(1, find(freqs >= 8 | freqs <=13)) should then give you the<br>> alpha frequency band spectrum.<br>><br>> hope it works<br>> -Simon<br>><br>> --<br>> Simon-Shlomo Poil<br>><br>> Neuronal Oscillations and Cognition Group (NOC)<br>> Department of Integrative Neurophysiology
(INF)<br>> Center for Neurogenomics and Cognitive Research (CNCR)<br>> Neuroscience Campus Amsterdam<br>> VU University Amsterdam<br>> De Boelelaan 1085, Room B-435<br>> 1081 HV Amsterdam, The Netherlands<br>><br>> E-mail: <a ymailto="mailto:simonshlomo.poil@cncr.vu.nl" href="mailto:simonshlomo.poil@cncr.vu.nl">simonshlomo.poil@cncr.vu.nl</a><br>> Phone: +31 20 5989408<br>> Webpage: <a href="http://www.poil.dk/s" target="_blank">http://www.poil.dk/s</a> and <a href="http://www.cncr.nl/" target="_blank">http://www.cncr.nl</a><br>><br>><br>><br>> 2011/6/19 nikos dhmou <<a ymailto="mailto:dhmoubagg@hotmail.com" href="mailto:dhmoubagg@hotmail.com">dhmoubagg@hotmail.com</a>>:<br>>> Hello, thank you for your answer my problem is how can i extract the alpha<br>>> band power spectrum only from spectopo. I get a vector of spec of 513 values<br>>> when I use spectopo for a set of epochs in a
condition which represent<br>>> frequencies up to 250 hz.<br>>> I only need to calculate this spec value for alpha band to get a mean of<br>>> power spectrum in two certain channels only for alpha band. Sorry but Im<br>>> novice in eeg programming power spectrum<br>>><br>>> Thanks,<br>>> nikos<br>>>> From: <a ymailto="mailto:simonshlomo.poil@cncr.vu.nl" href="mailto:simonshlomo.poil@cncr.vu.nl">simonshlomo.poil@cncr.vu.nl</a><br>>>> Date: Sun, 19 Jun 2011 02:47:19 +0200<br>>>> Subject: Re: [Eeglablist] Alpha power spectrum assymetry<br>>>> To: <a ymailto="mailto:dhmoubagg@hotmail.com" href="mailto:dhmoubagg@hotmail.com">dhmoubagg@hotmail.com</a><br>>>><br>>>> Dear Nikos,<br>>>><br>>>> You can, e.g., use either the 'spec' or 'pwelch' function. They will<br>>>> both give you a full power-spectrum, which you then need to
integrate<br>>>> in the alpha frequency band.<br>>>><br>>>> good luck<br>>>> -Simon<br>>>> --<br>>>> Simon-Shlomo Poil<br>>>><br>>>> Neuronal Oscillations and Cognition Group (NOC)<br>>>> Department of Integrative Neurophysiology (INF)<br>>>> Center for Neurogenomics and Cognitive Research (CNCR)<br>>>> Neuroscience Campus Amsterdam<br>>>> VU University Amsterdam<br>>>> De Boelelaan 1085, Room B-435<br>>>> 1081 HV Amsterdam, The Netherlands<br>>>><br>>>> E-mail: <a ymailto="mailto:simonshlomo.poil@cncr.vu.nl" href="mailto:simonshlomo.poil@cncr.vu.nl">simonshlomo.poil@cncr.vu.nl</a><br>>>> Phone: +31 20 5989408<br>>>> Webpage: <a href="http://www.poil.dk/s" target="_blank">http://www.poil.dk/s</a> and <a href="http://www.cncr.nl/"
target="_blank">http://www.cncr.nl</a><br>>>><br>>>><br>>>> 2011/6/17 nikos dhmou <<a ymailto="mailto:dhmoubagg@hotmail.com" href="mailto:dhmoubagg@hotmail.com">dhmoubagg@hotmail.com</a>>:<br>>>> > Hello, Im looking a way to calculate power spectrum for alpha band on a<br>>>> > set<br>>>> > of subjects on a set of epochs for two channels and compare anyone has<br>>>> > any<br>>>> > idea ? I use spectopo but it calculates spectrum untill 250 hz not alpha<br>>>> > band. Another problem i have is that the spectrums if i calculate right<br>>>> > give<br>>>> > pretty much the same spectrum for different conditions but that doesnt<br>>>> > make<br>>>> > sense because i want to compare the spectrums for different conditions<br>>>> ><br>>>> > thanks for the help<br>>>> >
nikos<br>>>> > _______________________________________________<br>>>> > Eeglablist page: <a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html" target="_blank">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a><br>>>> > To unsubscribe, send an empty email to<br>>>> > <a ymailto="mailto:eeglablist-unsubscribe@sccn.ucsd.edu" href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu">eeglablist-unsubscribe@sccn.ucsd.edu</a><br>>>> > For digest mode, send an email with the subject "set digest mime" to<br>>>> > <a ymailto="mailto:eeglablist-request@sccn.ucsd.edu" href="mailto:eeglablist-request@sccn.ucsd.edu">eeglablist-request@sccn.ucsd.edu</a><br>>>> ><br>>><br>><br>> _______________________________________________<br>> Eeglablist page: <a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html" target="_blank">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a><br>> To
unsubscribe, send an empty email to <a ymailto="mailto:eeglablist-unsubscribe@sccn.ucsd.edu" href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu">eeglablist-unsubscribe@sccn.ucsd.edu</a><br>> For digest mode, send an email with the subject "set digest mime" to <a ymailto="mailto:eeglablist-request@sccn.ucsd.edu" href="mailto:eeglablist-request@sccn.ucsd.edu">eeglablist-request@sccn.ucsd.edu</a><br>><br><br><br><br>-- <br>Simon-Shlomo Poil<br><br>Neuronal Oscillations and Cognition Group (NOC)<br>Department of Integrative Neurophysiology (INF)<br>Center for Neurogenomics and Cognitive Research (CNCR)<br>Neuroscience Campus Amsterdam<br>VU University Amsterdam<br>De Boelelaan 1085, Room B-435<br>1081 HV Amsterdam, The Netherlands<br><br>E-mail: <a ymailto="mailto:simonshlomo.poil@cncr.vu.nl" href="mailto:simonshlomo.poil@cncr.vu.nl">simonshlomo.poil@cncr.vu.nl</a><br>Phone: +31 20 5989408<br>Webpage: <a href="http://www.poil.dk/s"
target="_blank">http://www.poil.dk/s</a> and <a href="http://www.cncr.nl/" target="_blank">http://www.cncr.nl</a><br><br>_______________________________________________<br>Eeglablist page: <a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html" target="_blank">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a><br>To unsubscribe, send an empty email to <a ymailto="mailto:eeglablist-unsubscribe@sccn.ucsd.edu" href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu">eeglablist-unsubscribe@sccn.ucsd.edu</a><br>For digest mode, send an email with the subject "set digest mime" to <a ymailto="mailto:eeglablist-request@sccn.ucsd.edu" href="mailto:eeglablist-request@sccn.ucsd.edu">eeglablist-request@sccn.ucsd.edu</a><br><br><br> </div> </div> </div></body></html>