EEG in

[Curtin, Steven D (Steven)]

There's been some active research work done on this in the 70's by David
Rosenboom, now dean of the music school at Cal Arts and one of my
composition teachers at Mills.  He has a book out called "Biofeedback and
the Arts: Results of Early Experiments", a few copies of which are still
available from Frog Peak (http://www.sover.net/~frogpeak/).  I've tried
hooking up a Grass brand EEG to a synthesizer in 1980 or so and indeed
unless you structure it carefully the results are somewhat meadering (like
most music...).  

The Bodysynth is an EMG-based MIDI controller I did some consulting for in
the early-90's- this is quite cool- clench a fist or flex a muscle and a
swirl of notes or a drum beat of a specific loudness would result.  There
was a little feature on it in Keyboard in 1992.  GSR is another method that
picks up on the "mood" or tension of the user and can control a synth, this
is probably the cheapest and easiest to do.

Rosenboom once compared trying to get the information from a brain using
EEGs to trying to pick up the contents of a computer's memory by jamming a
jackhammer into the side of the case, but with practice you can get some
nice results, and having an EEG control a real synthesizer patch instead of
the usual static sine tone is very satisfying.

It can't be stressed too much that unless you optically isolate the
electrodes and amplifiers from the line voltage, the results can be
dangerous or even lethal.  The requirements for the amplifiers are also
incredibly stringent, since the EEG voltages are small in a very noisy
environment.  It can be done, though, and it would be cool to see a workable
design of this, I'd build and use it myself.

--------------------------------------------------------------
Steven Curtin  
http://www.emf.org/people_curtin.html
Lucent Technologies - Bell Labs Innovations
rm. 1A-229, 200 Laurel Ave S
Middletown, NJ 07748-4801  U S A
ph: (732)957-2996   fax: (732)957-6878
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> Late late last night, I was thinking once again of devious new ways to
> interface myself to my synths, when it occurred to me: A mini-EEG!
> 
> I just keep thinking this would be so cool, to play a nice line with both
> hands, and then as I get more into it and concentrate, my brain controls
> resonance and as I focus it all goes into squealy heaven. :)
> 
> Has anyone done experiments with this type of thing?  I imagine it'd be
> possible to DIY..  skin electrode to hi-gain low-noise amp, lopass filter
> at about 40 hz to reduce hum and noise and other signals not from the
> brain...  
> 
> Has anyone done anything remotely similar to this DIY?  I need a starting
> point...
>