Brain–Computer Interfaces - Index of

Brain Signals for Brain–Computer Interfaces
Jonathan R. Wolpaw and Chadwick B. Boulay
1 Introduction
This chapter describes brain signals relevant for brain–computer interfaces (BCIs).
Section 1 addresses the impetus for BCI research, reviews key BCI principles,
and outlines a set of brain signals appropriate for BCI use. Section 2 describes
specific brain signals used in BCIs, their neurophysiological origins, and their
current applications. Finally, Sect. 3 discusses issues critical for maximizing the
effectiveness of BCIs.
1.1 The Need for BCIs
People affected by amyotrophic lateral sclerosis (ALS), brainstem stroke, brain
or spinal cord injury, cerebral palsy, muscular dystrophies, multiple sclerosis, and
numerous other diseases often lose normal muscular control. The most severely
affected may lose most or all voluntary muscle control and become totally
“locked-in” to their bodies, unable to communicate in any way. These individuals
can nevertheless lead lives that are enjoyable and productive if they can be provided
with basic communication and control capability [1–4]. Unlike conventional
assistive communication technologies, all of which require some measure of muscle
control, a BCI provides the brain with a new, non-muscular output channel for
conveying messages and commands to the external world.
1.2 Key Principles
A brain–computer interface, or BCI, is a communication and control system that
creates a non-muscular output channel for the brain. The user’s intent is conveyed
J.R. Wolpaw (B)
Wadsworth Center, New York State Department of Health and School of Public Health, State
University of New York at Albany, Albany, NY 12201, USA
e-mail: wolpaw@wadsworth.org
B. Graimann et al. (eds.), Brain–Computer Interfaces, The Frontiers Collection,
DOI 10.1007/978-3-642-02091-9_2, C○ Springer-Verlag Berlin Heidelberg 2010
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