Slow potential topography

Several studies analyzing slow and long-lasting changes in scalp-recorded brain potentials have recently been published (e.g., Vitouch, Bauer, Gittler, M. Leodolter, & U. Leodolter, 1997). Such long-lasting changes turned out to be applicable as a fairly direct measure of cortical activity. Combined with multichannel recording, slow potential recording can serve as a data source for a noninvasive functional topography in cognitive psychophysiology. This paper describes methodological aspects crucial for true DC recording. Special properties of this brain activity signal will be addressed in the light of its complex origin. Since DC-EEG topography appears to be very promising for future research, specific aspects of multichannel DC-EEG handling, data processing, imaging, and analysis are specifically discussed. Finally, the advantages that cognitive psychophysiology may gain from DC-EEG topography are addressed.