Brain–Computer Interfaces - Index of

The Graz Brain-Computer Interface
Gert Pfurtscheller, Clemens Brunner, Robert Leeb, Reinhold Scherer,
Gernot R. Müller-Putz and Christa Neuper
1 Introduction
Brain-computer interface (BCI) research at the Graz University of Technology
started with the classification of event-related desynchronization (ERD) [36, 38] of
single-trial electroencephalographic (EEG) data during actual (overt) and imagined
(covert) hand movement [9, 18, 40]. At the beginning of our BCI research activities
we had a cooperation with the Wadsworth Center in Albany, New York State, USA,
with the common interest to control one-dimensional cursor movement on a monitor
through mental activity [69]. With such a cursor control it is in principle possible
to select letters of the alphabet, create words and sentences and realize a thoughtbased
spelling system for patients in a complete or incomplete “locked-in” state
[68]. At that time we already analyzed 64-channel EEG data from three patients
who had accomplished a number of training sessions with the aim to search for
optimal electrode positions and frequency components [38]. Using the distinction
sensitive learning vector quantizer (DSLVQ) [54] it was found that for each subject
there exist optimal electrode positions and frequency components for on-line
EEG-based cursor control. This was confirmed recently by BCI studies in untrained
subjects [2, 58].
2 The Graz BCI
The Graz BCI uses the EEG as input signal, motor imagery (MI) as mental strategy
and two types of operation and data processing, respectively. In one mode of
operation the data processing is restricted to predefined time windows of a few seconds
length following the cue stimulus (synchronous or cue-based BCI). In the other
G. Pfurtscheller (B)
Laboratory of Brain-Computer Interfaces, Institute for Knowledge Discovery, Graz University of
Technology, Krenngasse 37, 8010, Graz, Austria
e-mail: pfurtscheller@tugraz.at
B. Graimann et al. (eds.), Brain–Computer Interfaces, The Frontiers Collection,
DOI 10.1007/978-3-642-02091-9_5, C○ Springer-Verlag Berlin Heidelberg 2010
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