Friday, August 14, 2015

The Psychic Probe

In the summer my wife and I sometimes take long car trips, and I often listen to audiobooks while I drive to keep me awake and alert. During a recent trip I listened to Isaac Asimov’s Foundation trilogy. Regular readers of this blog know that I am a huge Asimov fan. I first read the Foundation series about forty years ago, and this was my third or fourth time through these delightful books.

In brief, the Foundation series tells the history of the decaying galactic empire, and describes the work of the psychohistorian Hari Seldon who has calculated mathematically how to reduce the duration of the dark ages following the empire’s fall from 30,000 years to merely 1000. All goes according to plan until the Mule, a mutant who can control other people’s emotions, causes all to go awry.

One of Asimov’s inventions in this future history is a device that can read minds, called the Psychic Probe. He writes in Foundation and Empire,
“The general threw away his shredded, never-lit cigarette, lit another, and shrugged. ‘Well, it is beside the immediate point, this lack of first-class tech-men. Except that I might have made more progress with my prisoner were my Psychic Probe in proper order.’

The secretary's eyebrows lifted. ’You have a Probe?’

‘An old one. A superannuated one which fails me the one time I needed it. I set it up during the prisoner's sleep, and received nothing. So much for the Probe. I have tried it on my own men and the reaction is quite proper, but again there is not one among my staff of tech-men who can tell me why it fails upon the prisoner. Ducem Barr, who is a theoretician of parts, though no mechanic, says the psychic structure of the prisoner may be unaffected by the Probe since from childhood he has been subjected to alien environments and neural stimuli. I don't know. But he may yet be useful. I save him in that hope.’ ”
Of course, Russ Hobbie and I don’t mention the Psychic Probe in the 5th edition of Intermediate Physics for Medicine and Biology….or do we? Asimov didn’t explain the physical mechanism behind the Probe, but I can speculate. Four candidates are:
PET and fMRI are too slow to accurately follow rapid brain activity. PET detects brain metabolism and fMRI detects blood flow, both of which are only indirectly related to neuron firing. My best guess for the Psychic Probe is some combination of MEG and TMS. Apparently the probe can damage the brain when used aggressively, which suggests TMS. But it can also read minds when used more gently, which points toward MEG. A combo TMS/MEG unit could therefore both detect and alter brain function.

While working at NIH in the 1990s, I studied both magnetoencephalography and transcranial magnetic stimulation. Yikes! I may be partially responsible for the invention of the Psychic Probe!

1 comment:

  1. TMS is FDA approved and a pretty widely used therapy for depression--so thanks Brad! There are also some big efficacy studies ongoing for its usefulness in PTSD and other mental health problems. I've tried TMS on myself when learning how to use it to study efficacy in post operative pain. Lemme tell you, stimulating your motor cortex--wow, absolutely Asimovian!