[Eeglablist] Calculating Alpha Asymmetry

[Campbell, Kathryn]

Hi,

I know there have been lots of questions about this but I have not found any that answer all of my questions.  I am completely new to using MATLAB and EEGLAB and am a bit overwhelmed.

The steps I have taken in the past to calculate alpha asymmetry were

1)      Segment continuous EEG data into 4 one minute blocks based on events markers

2)      For each block create a series of 2.048 second epochs overlapping by 50%

3)      Reject epochs with ocular or other artefacts (either manually or automatically)

4)      Calculate mean alpha power at each electrode site for each block using FFT with Hanning window.

5)      Use these figures to calculate alpha asymmetry (1n (R/L)
Unfortunately the system I now use to record EEG ( a very old version of neuroscan) doesn't seem have all of these functions available.

I am able to complete the first step using EEG lab but can't find a way to create overlapping epochs to move on to the next steps.

Is anyone able to help me?  Please bear in mind I'm not that familiar with MATLAB.

Thanks
Kathryn
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