The idea is that seizure would be induced by a specific electrical stimulus triggered through the optic nerve. “The onset of synchony and disruption of muscular control is said to be near instantaneous,” the 1997 Army report reads. “Excitation is directly on the brain.” And “100% of the population” is supposed to be susceptible to the effects — from distances of “up to hundreds of meters” — “[r]ecovery times are expected to be consistent with, or more rapid than, that which is observed in epileptic seizures.”

That’s not a lot of time — the Army’s analysis noted that a grand-mal seizure typically lasts between one and five minutes. But the analysis speculated that the seizure weapons could be “tunable with regard to type and degree of bodily influence” and affect “100% of the population.” Still, it had to concede, “No experimental evidence is available for this concept.”

The document cautioned that the effectiveness of incapacitating a human nervous system with an electromagnetic pulse (EMP) “has not been tested.” But the analysis speculated that “50 to 100 kV/m free field of very sharp pulses” would likely be “sufficient to trigger neurons or make them more susceptible to firing.”

When considered as a "ray gun" kind of weapon, I thought about referencing the pain ray from Edmond Hamilton's 1928 classic Crashing Suns and the Penfield wave transmitter from Philip K. Dick's 1968 novel Do Androids Dream of Electric Sheep?.

However, I realized that the idea of a weaponized display-induced epileptic seizure had already been written about by John Varley in his 1984 award-winning short story Press Enter. In the novel, a malignant artificial intelligence exploits a medical weakness of the main character by programming his monitor to induce a seizure:

We were almost through when her monitor screen began to malfunction. It actually gave off a few hisses and pops, so Lisa stood back from it for a moment, then the screen started to flicker. I stared at it for a while. It seemed to me that there was an image trying to form on the screen. Something three-dimensional. Just as I was starting to get a picture of it I happened to glance at Lisa, and she was looking at me. Her face was flickering. She came to me and put her hands over my eyes.

"Victor, you shouldn't look at that."

"It's okay," I told her. And when I said it, it was, but as soon as I had the words out, I knew that it wasn't. And that is the last thing I remembered for a long time.

Update: Reader Ken Ziegler reminds us of the LOOKER (Light Ocular-Oriented Kinetic Emotive Responses) gun from the 1981 film LOOKER written and directed by Michael Crichton. The device is a light pulse device that gives the illusion of invisibility by instantly mesmerizing its victims into losing all sense of time.

(LOOKER gun)

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