16.11.2012 Views

Brain–Computer Interfaces - Index of

Brain–Computer Interfaces - Index of

Brain–Computer Interfaces - Index of

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

358 B.Z. Allison<br />

It follows that BCIs are <strong>of</strong> no practical value to people who can otherwise<br />

communicate, and will not become more widely adopted unless they can become<br />

much faster.<br />

This perspective is mistaken. Instead, BCIs may provide useful communication<br />

to many new user groups, including persons with less severe movement disabilities<br />

and healthy people. The very definition <strong>of</strong> a BCI as a tool for communication and<br />

control is beginning to change. BCIs might also provide other functions, such as<br />

rehabilitation <strong>of</strong> different disorders [59, 60] (see also chapters “The Graz Brain–<br />

Computer Interface” and “Brain–Computer Interface in Neurorehabilitation” in this<br />

book), which are either unattainable or problematic for other interfaces.<br />

Furthermore, the critical progress that is needed is not in speed but other key<br />

factors like improved sensors, greater accessibility to nonexperts, and smoother<br />

integration with existing devices and s<strong>of</strong>tware. These and some other key factors<br />

are progressing at a rapid and potentially revolutionary pace. BCIs will therefore<br />

become practical tools for much wider user groups and goals than most people<br />

think. BCIs will not become ubiquitous in the next 10 years, but they will grow<br />

well beyond communication for severely disabled users.<br />

2 Key Factors in BCI Adoption<br />

Schalk [68] discusses BCI adoption much like adoption <strong>of</strong> other consumer electronics,<br />

such as radio, television, or DVDs. This approach, while unconventional<br />

within the BCI research community, is becoming increasingly popular with other<br />

EEG-based applications such as neuromarketing, lie detection, and sleep or alertness<br />

monitoring. These applications are not BCIs because they do not provide realtime<br />

feedback and/or do not allow intentional communication (see also chapter “Brain–<br />

Computer <strong>Interfaces</strong>: A Gentle Introduction”). However, progress with these and<br />

related systems could affect BCI development.<br />

Schalk [68] depicts the relationship between BCI price and performance, by<br />

which Schalk means bits/second. While a BCI’s information transfer rate (ITR) is<br />

important, other factors may be at least as important to potential users [11, 36, 83].<br />

The right table in Fig. 1 below summarizes these key factors. Each <strong>of</strong> these factors<br />

is influenced by both hardware and s<strong>of</strong>tware considerations. The two tables on the<br />

left side <strong>of</strong> Fig. 1 present three catalysts unique to BCIs and several related catalysts.<br />

The arrows indicate that these two types <strong>of</strong> catalysts influence each other and<br />

interact bidirectionally with the key factors. The arrows represent the strength <strong>of</strong> this<br />

influence. While progress in BCI catalysts and their key performance indices will<br />

influence related disciplines, this influence will be weaker than its reverse. There<br />

will be a lot more research in related catalysts than BCI-specific catalysts. While<br />

new sensors developed for BCIs might inspire improved ExG sensors, 1 electronics,<br />

1 This term is a contraction <strong>of</strong> electro-(anything)-gram. ExG sensors refer to any devices used to<br />

record people’s electrophysiological activity. The word “sensor” is used in its colloquial meaning<br />

throughout this chapter, not the stricter definition within electrical engineering.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!