[Eeglablist] ERSP vs Time-Freq

[Makoto Miyakoshi]

Dear Iman,

> ERP Time Freq is |F(mean(x))|

ERSP is  mean(|F(x)|)

This is much easier to understand for me. They are not equivalent. Single
trial phase-variable power modulation can not be observed with the former,
correct?

Makoto

2014-03-05 1:01 GMT-08:00 Iman M.Rezazadeh <irezazadeh at ucdavis.edu>:

> Hi all ,
>
> ERP Time Freq is |F(mean(x))|
>
> ERSP is  mean(|F(x)|)
>
>
>
> Best
>
> Iman
>
>
>
> *From:* eeglablist-bounces at sccn.ucsd.edu [
> mailto:eeglablist-bounces at sccn.ucsd.edu <eeglablist-bounces at sccn.ucsd.edu>]
> *On Behalf Of *Makoto Miyakoshi
> *Sent:* Thursday, February 27, 2014 10:48 PM
> *To:* Iman M.Rezazadeh
> *Cc:* EEGLAB List
> *Subject:* Re: [Eeglablist] ERPS vs Time-Freq
>
>
>
> Dear Iman,
>
>
>
> I'm not sure if there is any difference... I was not aware of it.
>
> You may want to check dftfilt3() for the EEGLAB default wavelet (and let
> us know what you find).
>
>
> > And what is the difference btw evoked and induced potential.
>
> Evoked is phase-reset to stimulus onset and induced is not. I thought
> Galambos proposed this distinction, but I could be wrong.
>
>
>
> Makoto
>
> 2014-02-27 16:35 GMT-08:00 Iman M.Rezazadeh <i_rezazadeh at yahoo.com>:
>
> Hi ,
>
> What is the difference btw the traditional time-freq representation of an
> ERP and ERPS? Are they the same? Since Suppose,  we have two epochs x1 and
> x2 with zero means , then
>
>
>
> 1-      In traditional  way :  we make an average out of them x_avg and
> then make the Fourier transform of them F(x_avg)=F([x1+x2]/2 ) =
> F(x1/2)+F(x2/2)= [F(x1) + F(X2)] / 2
>
> 2-      In ERPS we calculate time-freq for each epoch F(x1) and F(x2) and
> then make the average ERPS=[ Fx(1) + F(x2)] / 2
>
>
>
>
>
> And what is the difference btw evoked and induced potential. My questions
> are mostly from Chp 3 of the Oxford Handbook of Event Related Potential
> Components pg 77-78
>
>
>
> Best
>
> Iman
>
>
>
>
>
> --
>
> Makoto Miyakoshi
> Swartz Center for Computational Neuroscience
> Institute for Neural Computation, University of California San Diego
>



-- 
Makoto Miyakoshi
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego
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