Need idea for Westinghouse project

Mark Robert Thorson mmm at cup.portal.com
Sat Nov 3 20:11:34 EST 1990


A reasonable application of computers for an introductory C programmer
would be the collection of statistics.

I remember how impressed I was to learn about the technique known as
the evoked potential.  Under computer control, you flash an input stimulus,
then begin sampling from your electrodes.  On a single trial run, the data looks
like random noise, but collect 100 trials and average them out, and you see 
a distinct characteristic wave in response to the stimulus.

The stimulus can be almost anything.  The experiment I saw used bit-patterns
flashed onto the frame buffer of a computer-graphics display.

The response is a bit sticky.  If I'm correct, the GE show forbids venipuncture
of warm-blooded animals.  I don't know what the regulations are on surface
electrodes, but I'd guess that recording from humans and mammals is verboten.

You can do anything you like with invertebrates.  I suggest some sort
of measurement of the visual processing of a snail or cockroach.
Develop equipment to take brainwaves, then do evoked-potential work.

For example, you clamp down the animal by gluing it to a styrofoam block.
Your stimulus is a dark/light edge moving from left to right.  This is done
by having a black card under the tension of some rubber bands.  The computer
flips a bit, and a coil releases a catch so the card flies past the animal's
visual field.  Immediately when the command to release the catch is given, the 
computer begins recording brainwaves at 1/100 second intervals.  Average
100 trials, and you should have some sort of interesting result.

Sound is another easy stimulus variable.  The computer emits a sound from
its loudspeaker, and you capture a block of data from an A/D converter.
Average 100 trials, and you should get some sort of characteristic wave.

Some prominent scientists believe you can measure IQ by recording the
evoked potentials observed on scalp electrodes applied to human subjects upon
whom certain test images are flashed.  I can provide references if needed.



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