[Eeglablist] Removal of distortion due to overlapping ERP responses - ADJAR filter

Niko Busch mail at nikobusch.net
Mon Aug 2 10:38:00 PDT 2010


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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!

Best,
Niko


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