Hi everyone!
I'm working with a dataset with imagery movement and I want extracted the features using ERS/ERD. It is possible?
I'm trying to compute these features following the paper of Bernhard and Graimman, (see attach file), but I don't understand how it could be used like features. Also, how can i plot the ERS/ERD. ?
Attach a piece of code that computes the ERS/ERD for alpha band. (I'm using EEGLAB)
Thanks !
Jaime,
To my knowledge, within the basic EEGLAB package, you should use an event-related spectral perturbation calculation for this. It has different options, and the default is a wavelet-based decomposition rather than the FFT which if I remember correctly, Pfurtscheller and colleagues utilized in their initial papers describing the outcome. You have the option to use FFT for this data, which may help with lower frequencies.
https://sccn.ucsd.edu/wiki/Chapter_11:_Time/Frequency_decomposition
I'm afraid I cannot help you with a code for this, however, if you take advantage of the epoch and EEG data structure in EEGLAB, you should be able to write your own code.
I hope this helps a little bit!
Kind regards,
Chris
What is the main differences between ERD/ERS features with bandpower features ?
From what I understand, it gives you a mathematically similar outcome, that is, what changes occur in the spectral activity with respect to a time-locked event. So while it isn't the exact same mathematics as ERD/ERS, the ERSP is comparing the change in the power at each frequency at each time point, and your outcome (color) is the logarithmic scale change in power (dB). So it doesn't provide a % change like some ERD/ERS equations will, but the ERSP is what I am currently using in place of ERD/ERS.
This help article may provide a little more assistance:
https://sccn.ucsd.edu/pipermail/eeglablist/2012/004755.html
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