|
|
Thomas F.
Collura, Ph.D., P.E.
October 17, 1996
Introduction
The
low-cost, portable EEG machine has a short history.
1 and 2-channel units for under $1300 have only been
available since the late 1990's. As such,
applications are in an embryonic stage. Nonetheless,
a wide range of applications have been identified,
and are being actively pursued. These include:
1) EEG Biofeedback
* Personal/self-improvement/meditation
* Therapist-guided relaxation, etc.
* Peak-performance training, "Brain calisthenics"
* Adjunct to EMG, GRS, etc.
* Treatment of ADD & other clinical disorders
2) Computer Control & Communication
* "Thought-controlled" cursor, switch
* Brainwave-controlled games
3) Entertainment, Virtual Reality
* Control of music, graphics
* Control of VR Displays
* Interface to Light/Sound machines
4) Education, Research
* Labs, experiments, demonstrations
* Monitoring classroom/audience attention
5) Military, Commercial
* Screening & evaluating pilots, operators
* EEG-based Cockpit controls, pilot monitoring
* Assessing consumer reactions
Each of these application areas has its own
requirements, history, and prospects for low-cost
EEG Biofeedback
EEG was first explored as a biofeedback modality by
Kamiya, Brown, and others, beginning in the 1960's.
Initial work led to a generalized relaxation model,
based primarily on the alpha rhythm. Training was
often done solely for the strengthening of the alpha
rhythm, without regard for other variables, or other
brain rhythms. It was found that developing the
alpha rhythm, in and of itself, had limited value.
Continued work has developed methods that use other
rhythms, or combinations of rhythms, in both
encouragement and discouragement protocols, to teach
users to control the relative amounts of rhythms,
providing much more precise control of the brain.
Computer Control & Communication
The use of the EEG to control or communicate with a
computer is an application that has undergone slow
but steady development since the 1960's. Early work
by Pinneo and others attempted to record "latent
motor potentials" caused by a person thinking a
work, such as "up" or "down." More recently,
investigators have been looking for signals that
appear controllable, and adapting the system to
them. One of these is the "sensorimotor rhythm" (SMR),
that has been found to be under a certain amount of
conscious control. Generally, the user uses
"affective" thoughts, such as "feeling light" or
"stopping thinking" to cause the desired rhythm.
Entertainment, Virtual Reality
Entertainment application include EEG-controlled
composition and performance, including
"audience-participation" situations.
Virtual Reality displays can use EEG to modulate,
alter, or otherwise control any aspect of the
virtual world. For example, a system could be made
sensitive to the individual's overall cognitive and
emotional state, to produce an appropriate world.
This could include changing the colors or sizes of
objects, controlling sunrise and sunset, or causing
the appearance or removal of features, or even of
the entire location.
Education, Research
EEG is not well known below the level of the
graduate student. Very few colleges, and no known
high schools, offer any opportunity for students to
record, study, and understand the EEG. This is
unfortunate, because it is becoming increasingly
clear that a basic understanding of the EEG and its
properties, especially with personal experience of
recording (ideally one's own) EEG, can provide
valuable insight into the brain, as well as the
mind. For example, individual differences can be
seen in EEG patterns between people, and EEG changes
in various tasks or circumstances can also be
revealing. It would be desirable for a greater
number of students, at and below the undergraduate
level, to have direct experience with, and
understanding of, the EEG.
There is a certain amount of popular use of phrases
like "left brain," "right brain," "being in synch,"
"alpha waves," and other related concepts. We like
to understand how the brain operates, but often use
concepts that we must for the most part, take for
granted, because there is no practical way to check
any of these ideas out. With the availability of
low-cost, scientifically sound brainwave monitors,
it becomes possible to effectively record and see
anyone's brain rhythms, their left and right-brain
activity, balance, synchrony, and other variables.
Military, Commercial
The military has a long history of studying the EEG;
some of the earliest telemetric monitoring and
analysis was developed by NASA during the 1960's, in
connection with the space program. This was designed
primarily to monitor the pilots' state of health and
consciousness. In addition, the Air Force has had a
long-standing program to develop EEG-based pilot
controls for the cockpit. These include
evoked-potential based system, which attempt to
rapidly detect and act upon changes in the pilot's
gaze, or level of attention, to a display item.
Another ongoing area is alertness monitoring for
commercial and military transportation systems.
Initial work used the ongoing EEG, and more recent
work uses event-related potential, and neural
networks to interpret the waveforms.
Purely commercial applications include studying
subjects who are viewing advertising material or
evaluating products, primarily to assess their level
of interest and/or arousal.
|
