BCIs Based on Signals from Between the Brain and Skull

Abstract

This chapter provides an introduction to electrocorticogram (ECoG) as a signal source for brain–computer interfaces (BCIs). I first define ECoG, examine its advantages and disadvantages, and outline factors affecting successful ECoG experiments for BCI. Past and present BCI projects that utilize ECoG and have published results through early 2008 are then summarized. My own ECoG work with the University of Michigan Direct Brain Interface project is described in detail, as the first and (at the time of writing) longest running targeted exploration of ECoG for BCI. The well established ECoG research at the University of Washington is described only briefly, since Chapter “A Simple, Spectral-change Based, Electrocorticographic Brain–Computer Interface” in this volume provides a first-hand description. This chapter concludes with a few thoughts on the growth of BCI research utilizing ECoG and potential future applications of BCI methods developed for ECoG.