Computer-based electroencephalography: technical basics, basis for new applications, and potential pitfalls.

EEG has been recorded on paper-based analog systems for over 50 years. In the past 5 years, computer-based digital systems have become more widely used. Digital systems eliminate some artifacts that plagued analog recordings but introduce subtle new problems including aliasing and dynamic range. Digital systems allow reformatting of the same EEG segment using different gain, filter and montage settings. The digital signal allows for measurement and computations on the EEG, leading to applications such as power spectrum, topographic mapping, and spike or seizure detection.