[Eeglablist] preparation for ICA clustering

[Philip Michael Zeman]

Hi Piotr

Clustering performs the operation of 'grouping' components together with similar qualities and there are multiple component properties by which you can perform clustering.  If you are clustering components based on both (1) the frequency content of source waveforms and (2) dip-fit 3D location of the equivalent model dipoles, those components with similar qualities determined by (1 and 2) will (should) be grouped together.

This means 2 things.  First, brain activities (with brain-like frequency content) with modelled origins that are similar to each other should be grouped together. Second, artefacts (with artefact-like frequency content) with modelled origins that are similar to each other should be grouped together.  In this example, artefacts get put into different clusters than brain activity components.  Hence, clustering can actually help you identify artefacts from real brain activity sources.

Given the argument above, including eye-artefact components in your clustering process may be advantageous in helping your understand your data and separating artefacts from brain activity components.

Hope this helps.  And of course, other opinions are welcome.

Regards,

Philip Michael Zeman


  ----- Original Message ----- 
  From: Piotr Jaskowski 
  To: eeglablist at sccn.ucsd.edu 
  Sent: Monday, November 02, 2009 1:11 AM
  Subject: [Eeglablist] preparation for ICA clustering


  Dear All,

                 I am preparing my data for ICA clustering. What is unclear for me is if I should remove ICs which were (by eye) identified as bad components before submiting ICs for clustering? 

  Could anyone help me?

   

  Best, Piotr

   

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

  Prof. Piotr Jaskowski, Ph.D.

  Department of Cognitive Psychology

  University of Finance and Management

  Pawia 55, 01-030 Warszawa, Poland

  http://cogn.vizja.pl

   







--

Specjalna oferta ksiazek i podrecznikow: http://oferta.vizja.net.pl







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