[Eeglablist] Spectopo - Absolute or Relative Power?

[Makoto Miyakoshi]

Dear Sue,

> Are the power output values, of the Spectopo function, absolute power, or
have they been normalized?

It's NOT normalized. It's just log converted in the following way: If you
have a sine wave with peak amplitude of +/-1uV, you'll see 0dB in the
spectrum. If the sine wave is +/-10uV, you'll see 20dB. If it's +/-0.1uV,
it'll be -20dB.

Makoto

On Wed, Oct 28, 2015 at 4:54 PM, Sue Peters <sp at suepeters.com> wrote:

> An easy question, but my review of the past discussion has confused me.
> Are the power output values, of the Spectopo function, absolute power, or
> have they been normalized?  The description of the function uses the word
> "relative" but it's not clear if it means relative in terms of topography,
> or in terms of normalization (i.e. relative power).
>
> Thanks!
> Sue Peters
>
>
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-- 
Makoto Miyakoshi
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego
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