A study on the reference electrode standardization technique for a realistic head model.

One oldest technical problem in EEG practice is the effect of an active reference on EEG recording, and it is especially important for identifying the temporal information of EEG recordings. To solve this problem, a reference electrode standardization technique (REST) has been proposed for a concentric three-sphere head model. REST, based on an equivalent distributed source model, reconstructs the potential with a reference at infinity from the potential with a scalp point reference or with the average reference. In this paper, investigated was the REST for a realistic head model. The results of simulation studies show that the potential reconstruction for the realistic head model is more sensitive to noise than that for the concentric three-sphere head model, so a regularized inverse by truncated singular value decomposition was introduced. The results confirm that REST is still an efficient method even for a realistic head model especially for the most important superficial cortex region.