[Eeglablist] Separating out Alpha from mu oscillations

[Chuck Telestel]

Hi, 

One way, not the only way, would be to use current source densities or apply a Hjorth transform to the data. The effect is that more global alpha rhythms won't mask your mu rhythms. Use the electrodes over the motor regions contra-lateral to movement (C3 & C4: 10/20 system). 

It also a good idea to have pre-movement data for a baseline correction. You could use time-domain and frequency domain representations. Your mu-desychronisation will be clearly visible in the upper alpha band (approx. 10-12hz). Bear in mind that the alpha band varies across individuals so not everyones upper alpha will neatly fall into this band.

There are a couple of ways, but the above gives decent results. Good luck.

Matthew

On 25 Mar 2014, at 3:58 PM, B L <thirstyforknowledge123 at gmail.com> wrote:

> Hi,
> 
> I guess this topic has been discussed in the past but I cant find an effective solution.
> 
> We know that, it  is very common for the alpha oscillation to have influence up to almost the frontal electrodes. My question is - If we are interested only in mu rhythm in a visual-motor task, what is the best way to tease out the alpha activity from the motor regions so the comparison across groups is more effective?
> Will ICA work better for this(just identifying the alpha component and removing it)? Is there any other method researchers commonly use for this purpose?
> Any help is much appreciated.
> 
> Thanks!
> Bala 
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