[Eeglablist] Is it safe to apply ICA weights to data at different sampling rates?

[Iman M.Rezazadeh]

Hi, 

I am trying to explain my opinion using the microstates approach  “Spatiotemporal Analysis of Multichannel EEG: CARTOOL;  Denis Brunet, MicahM. Murray and Christoph M.Michel”

 

Each brain’s microstate corresponds to a period of coherent synchronized activation of a large scale neuronal network. It does not change instantaneously (like by every msec).  This corresponds well to the proposal that neurocognitive networks evolve through a sequence of quasi-stable coordination states, rather than a continuous flow of neuronal activity. It has been shown that microstates and ICA components reveal similar neural activation maps[Reference: the paper I mentioned above].

 

Now, suppose you the sampling rate for one experiment is 1000Hz (1msec time difference between two consecutive samples) and you want to down-sample it to 500Hz (2 msec time difference…) .  there is not much difference btw the microstates maps since 1 or 2 msec time period is not that much the brain could switch btw one microstate to another (which leads to changing of ICA maps). But if you down-sample the signal by 10 time( like 100Hz) then one might be skeptical about the changes in the microstates maps/ICA maps.

 Best

Iman

 

-------------------------------------------------------------

Iman M.Rezazadeh, Ph.D, M.Sc, B.Sc.

 

Research Associate II 

Semel Intitute, UCLA , Los Angeles

& Center for Mind and Brain, UC DAVIS, Davis

 

 

 

From: eeglablist-bounces at sccn.ucsd.edu [mailto:eeglablist-bounces at sccn.ucsd.edu] On Behalf Of Cockburn, Jeffrey
Sent: Monday, June 2, 2014 10:21 AM
To: eeglablist at sccn.ucsd.edu
Subject: [Eeglablist] Is it safe to apply ICA weights to data at different sampling rates?

 

Greetings.

 

A while back I computed and exported ICA weights for data that was down-sampled to 250Hz. I'd like to do revisit that data at its original 500Hz sampling rate. Is it safe to apply the 250Hz ICA weights to the 500Hz data? Is it safe to apply ICA weights to data with a different sampling rate in general?

 

Thanks.

 

-- Jeff

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