[Eeglablist] Removal of distortion due to overlapping ERP responses - ADJAR filter
Frank H Duffy
fhd at sover.net
Wed Aug 4 08:23:57 PDT 2010
A key thing is to understand whether, on physiological grounds, there
may be an interaction between the two conditions, i.e., A alters the B
waveform (or the opposite) as seen for the long latency AER if you
closely pair auditory clicks. Is the problem a simple arithmetic
(result =A+B) or is there likely to be a strong interaction effect
between A and B? Indeed some people estimate the degree of interaction
by adding A alone and B alone signals and compare to the A+B experiment.
Frank fhd at sover.net
On 8/2/2010 1:38 PM, Niko Busch wrote:
> Hi everyone,
> I am looking for a way to remove the distortion from an ERP waveformthat is due to overlapping ERP responses to different events. I willemploy an experimental paradigm in which an experimental event A isfollowed by an event B after a variable SOA on each trial. My interestis in the ERP evoked by the Bs. However, the resulting ERP waveform -time-locked to event B - will be "contaminated" by the responses to theAs.
> It seems that people use two different approaches to remove the contribution of the As:
> 1. Include trials with A events only and then subtract the average of A from the average of A+B.
> 2. A convolution approach - the ADJAR method specified in this paper:
> Woldorff MG. Distortion of ERP averages due to overlap from temporallyadjacent ERPs: analysis and correction. Psychophysiology. 1993Jan;30(1):98-119.
> Has anyone implemented ADJAR or something similar in Eeglab/Matlab andis willing to share the code? Any help would be very much appreciated!
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to eeglablist-request at sccn.ucsd.edu
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the eeglablist