[Procedures for on-line minimizing of eyelid and vertical eye movement artefacts in the EEG]

The analysis of electroencephalograms and event-related potentials may be difficult by the presence of eyelid and eye movement artifacts. In this paper a method is described, which allows a relatively simple on-line correction of vertical ocular activity, measurable by electro-oculogram, in several EEG channels. Eyelid and eye movement artifacts are being manifest in a different extension at a different EEG recording position. Using the electrooculogram, with the aid of a simple electronic device it is possible to differ between eyelid and eye movement artifacts, which will be corrected selectively. If only midline derivations are evaluated (Fz, Cz, Pz) the vertical EOG is sufficient and horizontal EOG may be left out from the correcting procedure. The efficiency of the procedure is proved by EEG and ERP records.