Information Technology Reference
In-Depth Information
As for using EEG in music, as early as 1934 a paper in the journal
Brain
had
reported a method to listen to the EEG (Adrian and Matthews
1934
). But it is now
generally accepted that it was composer Alvin Lucier who composed the
rst
musical piece using EEG in 1965:
Music for Solo Performer
(Lucier
1976
).
Composers such as Richard Teitelbaum (
1976
), Rosenboom (
1976
) and a few
others followed with a number of interesting ideas and pieces of music.
The great majority of those early pioneers who have attempted to use the EEG to
make music have done so by direct soni
cation of EEG signals. However, in 1990,
David Rosenboom introduced a musical system whose parameters were driven by
EEG components believed to be associated with shifts of the performer
s selective
attention (Rosenboom
1990
). Rosenboom explored the hypothesis that it might be
possible to detect certain aspects of our musical experience in the EEG signal. This
was an important step for BCMI research as Rosenboom pushed the practice
beyond the direct soni
'
cation of EEG signals, towards the notion of digging for
potentially useful information in the EEG to make music with.
1.3
Approaches to Brain
-
Computer Music Interfacing
Research into brain
computer interfacing (BCI) is concerned with devices whereby
users voluntarily control a system with signals from their brain. The most com-
monly used brain activity signal in BCI is the EEG, which stands for electroen-
cephalogram. In such cases, users must steer their EEG in a way or another to
control the system. This informs the hard approach to BCMI: a system whereby the
user voluntarily controls music. However, it is arguable that voluntary control may
not be always necessary for a music system. For instance, a music system may
simply react to the mental states of the user, producing music that is not necessarily
explicitly controlled. We shall refer to such systems as soft BCMI, as opposed to
hard BCMI. In this chapter, however, we will give focus to hard BCMI: we are
interested in active, voluntary control of music. An example of passive soft BCMI
is introduced in Chap.
13
.
A hard BCMI system requires users to produce patterns of brain signals vol-
untarily to control musical output and this often requires training. Therefore,
playing music with a BCMI should normally require ability and learning. This can
be attractive for many individuals; for example, as an occupational therapeutic tool
for severe physical impairment.
In a previous paper, we identi
-
ed two approaches to control the EEG for a BCI:
conscious effort
and
operant conditioning
(Miranda et al.
2011
). Conscious effort
induces changes in the EEG by engaging in speci
c cognitive tasks designed to
produce speci
c EEG activity (Curran and Stokes
2003
; Miranda et al.
2005
). The
cognitive task that is most often used in this case is motor imagery because it is
relatively straightforward to detect changes in the EEG of a subject imagining the
movement of a limb such as, for instance, the left hand (Pfurtscheller et al.
2007
).
Other forms of imagery, such as auditory, visual and navigation imagery, can be
used as well.
