Brief Introduction to Electroencephalography

Electroencephalography (EEG) has a long history in neuroscience starting with its original description in humans by Hans Berger in 1929 (Berger, 1932). Investigations of EEG under anesthesia started soon after in the mid-1930s (Gibbs, 1937). No single methodology paper can credibly cover all of the issues relating to this rich field. The purpose of this chapter is to introduce some caveats that complicate and inform analysis of the EEG. Special emphasis will be given to common issues such as choice of reference electrode, filtering, artifact rejection, and spectral analysis. We will specifically emphasize high-density EEG recordings that have become the norm due to technological improvement in electrode and data acquisition design methods. In the last section we will discuss some applications of EEG analysis techniques to the study of the effects of anesthetics on the nervous system.