[Eeglablist] How to do TF analysis with eeglab
arno at salk.edu
Fri Mar 19 08:23:40 PST 2004
>I want to do time-frequency analysis with eeglab. My data is 3-minute-long steady state visual evoked potential. I have trouble with doing time-frequency anaylsis with eeglab. The message is "Epochs must be extracted before running the function". Only one epoch for my data. The time-frequency analysis can not be used for one- epoch data? How can I do?
You may use the specgram function of the Matlab signal processing
toolbox. For instance,
figure;specgram(EEG.data(1,:), 512, EEG.srate, 256);
To respond to the question of Pradyumna S Upadrashta about the
difference between timef and specgram, specgram computes the spectrogram
(continuous time-frequency decomposition) and timef() compute the
average spectrogram of a collection of epochs (and optionally subtract
the baseline activity). The equation timef uses is described in the
EEGLAB paper (J Neuroscience methods).
In a future version of EEGLAB, we will allow timef() to plot the
spectrogram too (and assess significant changes).
*Arnaud Delorme, Ph.D.*
Computational Neurobiology Lab, Salk Institute
10010 North Torrey Pines Road
La Jolla, CA 92037 USA
*Tel* : /(+1)-858-458-1927 ext 15/
*Fax* : /(+1)-858-458-1847/
*Web page *: www.sccn.ucsd.edu/~arno <http://www.sccn.ucsd.edu/%7Earno>
*To think upon*:
If you don¡¯t live it, it won¡¯t come out your horn.
More information about the Eeglablist