Off-line removal of ocular artifacts from event-related potentials using a multiple linear regression model.

A method for correction of event-related potentials (ERP) and cortical DC shifts, disturbed by eyeblink and eye movement potentials, is described. The correcting algorithm employs a multiple linear regression model with random regressors which prevents an incorrect calculation of the propagation factor when both ocular potentials and event-related cortical potentials occur together. This propagation factor is calculated for each event-related EEG record. Segmentation of the record into 2.56 s time intervals guarantees, moreover, calculation of different propagation factors for eyeblinks and eye movements within a single trial. The correcting algorithm is executed off-line with the propagation factors calculated from the experimental data proper. A correction is carried out only when the EOG has a significant influence on ERP. The application of the procedure is illustrated by individual examples.