[Eeglablist] Can I apply cluster weights to all EEG data?

[Cooper, Rachel]

Hi all,

This is partly a theoretical question and partly a practical one. I have a study with 2 participant groups and 3 repeated measures factors. So far I have run ICA on my epoched data and then used cluster analysis. My problem is that the clusters which are most interesting (i.e., they look like relevant ERPs and contain the most ICs) contain lots of ICs from some participants and none from others. I assume this must be the case in any study with a between subjects factor.

A suggestion from my PhD supervisor was to find the weights for the cluster and then apply these weights to the EEG data for every participant and every condition. That way I can compare these new component activations across my conditions/subjects knowing that the same IC component is being compared. Is it safe to do this theoretically?

On a practical level, I have found the data used to plot the cluster scalp map in STUDY.cluster(clust).topo. However, I don't know how I would use this to apply cluster weights to the rest of my data as it is not a matrix of channels x ICs like the regular ICA weights. Is there another way to access the weights for a cluster?

Any help is much appreciated and if you need more detail please let me know
This is a fantastic list!

Rachel

Rachel Cooper
PhD researcher
Department of Psychology,
University of Essex,
Wivenhoe Park,
Colchester,
Essex,
CO4 3SQ