SOME CONSIDERATIONS ON ESTIMATING EVENT-RELATED BRAIN SIGNALS

Understanding the timing of mental acts is one of the prominent questi ons in information processing research. The analysis of event related potentials (ERP) with their high temporal resolution might make access to cognition related brain activity possible. We consider three major problems which make the application of ERPs questionable and then pro pose some solutions to these problems. The primary problem concerns th e separation of the ERPs from the background EEG which is not related to the stimulus. The most common method used is averaging. We argue th at this is not the most appropriate method and suggest an alternative for estimating the signal in single-trial recordings. Artifacts presen t a second problem. We will first review established methods of dealin g with eye-movement artifacts and then propose an alternative. We will also report on current work on the parametrisation of single-trial si gnal estimates, which constitute the third problem considered.