Alternative Controllers

[Steven Curtin]

At 07:46 PM 8/16/97 -0400, you wrote:
>Greetings,
>        I have started experimenting with an EEG (Electroencephalograph) 
>CV to midi interface.
>Sounded very straight forward at first but our brainwaves don't exactly 
>track our immediate thoughts and the resultant control voltages obtained
>from the device can be very useful one second and be useless the next.
>Anyone out there familiar with high accuracy medical instrumentation?
>Anyone insane enough to collaberate on this project? 
>If anything the EEG looks awesome for live shows!
>All of the electrodes hanging off your head.                           
>Free brainwave hardcopies for your adoring audience.

Check out a book by a teacher of mine, David Rosenboom, called "Biofeedback
and the arts: results of early experiments".  You should be able to find it
in many public libraries or through inter-library loan.  I can also tell
you how to geta coy if you're interested- their might be some around still.
 He's now head of the music department at Cal Arts and has done this stuff
for 20 years.  You can't track thoughts or anything but with a little
practice you can control your EEG output and hear immediate musical
results, and it's quite cool once you get it going.  

Other biofeedback sensors work too- GSR which measures skin conductivity-
this is what most of the cheap units do.  I worked for a couple of years on
an EMG-based biofeedback controller called the Bodysynth.  It's now used by
artists like pamela Z in SFO and Laurie Anderson was working with it for a
while as well.  It sensed the output of your muscles which sounds like an
envelope of white noise.  This can be processed with an envelope follower
for use as a control voltage.  The bodysynth generated MIDI output but the
idea would probably work better with a nice modular synth.

One big big warning- DO NOT attempt to power any of this stuff off of the
wall unless you have an optically isolated power supply of batteries.  Your
output jack should also be optically isolated.  Think of the consequences
of a reverse-polarity spike like the kind you got in high school when you
touched the wrong microphone, only this time connected to your scalp.

Steve C

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Steven Curtin  
http://www.emf.org/people_curtin.html
Lucent Technologies - Bell Labs Innovations
rm. 3C-208, 200 Laurel Ave S
Middletown, NJ 07748-4801  U S A
ph: (908)957-2996   fax: (908)957-6878
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