[Eeglablist] Remove ERP before time/freq ?

[Scott Makeig]

Stan -

A comment on your suggestion to subtract the ERP average from every epoch
before time/frequency decomposition:  This suggestion is reasonable IF you
assume that the ERP and the ongoing EEG in the recorded channel or component
are separable - e.g., if they have separable causes and/or generator
locations, AND the shape, size, latency, etc. of the stimulus-evoked
response is constant. These are large assumptions, however, and beyond very
early sensory potentials (in the first few ms after tachistoscopic onset of
a sensory stimulus), they do not seem wholly defensible. For this reason, I
would not recommend this as normal procedure.

Scott

-- 
Scott Makeig, Research Scientist and Director, Swartz Center for
Computational Neuroscience, Institute for Neural Computation, University of
California San Diego, La Jolla CA 92093-0961, http://sccn.ucsd.edu/~scott
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