3
$\begingroup$

Suppose a person's head is stabilized in the middle of a dome. The inside of the dome is lined with very fine, weak and accurate masers. Suppose then that these masers are set such that they may overlap in very specific positions within the skull at specific times, stimulating the brain tissue. Using conceivable refinements of today's technology and neuroscience, could such a device be used produce predictable effects on a person's brain without harming it? If so, what kinds of effects might be possible?

Specifically, I'm wondering about the potential of such a device as a possible means of control; stimulating pleasure or pain or various emotional responses, triggering memories, erasing them, changing their associations, etc.

Edit: I’ve received some helpful answers! It does seem most of the answers deal with relatively general heating. My understanding is that the most precise laser beams currently developed are in the range of 10-20 micrometers in diameter. If the theoretical peak accuracy of masers is similar, it seems that direct neuron targeting could be possible. What I’m not entirely clear on is the theoretical penetration through biological tissue of such a beam. If the maser could have any effect on tissue the middle of the brain, without cooking the tissue on the outside, it seems direct targeting could be possible through the right focusing and overlapping (similar to what is done with x-rays as Jani Miettinen pointed out). I’m not sure what the state of research is on this topic; how the penetration of a maser might behave differently than the kind of general microwave found in a kitchen. The second point I’m not clear on is wether or not an individual neuron can be stimulated to fire with a precise thermal insult. In thermoreceptors, this is obviously the case, otherwise I’m not sure.

$\endgroup$
1
  • $\begingroup$ I don't think I know enough to answer but off the cuff, I can't imagine a maser is what you want: microwaves don't penetrate well. If you went to the other end of the spectrum, you'd at least get the deep tissue penetration you desire, though probably all you'd do is give them cancer... $\endgroup$
    – JamieB
    Dec 24, 2022 at 19:30

6 Answers 6

8
$\begingroup$

Microwaves, when absorbed, interact with the rotational and vibrational states of the interacting molecules. In layman terms they warm them up.

As far as I know, the only thing that excess heat does to organic matter is denaturating it. Again, in layman terms it means it's being cooked.

Which, not by chance, is what happens in a microwave oven: microwaves heat up the water in the food until it is cooked.

It might be that denaturation of certain proteins in the neurons can give, as side effect, certain sensorial effects, however such effects would probably drown in the mayhem of the brain being cooked.

$\endgroup$
4
  • 1
    $\begingroup$ And weak masers won't have any effect whatsoever. The cooling system of the brain is perfectly able to deal with a few excess watts. $\endgroup$
    – AlexP
    Dec 24, 2022 at 8:53
  • $\begingroup$ Am I incorrect in thinking that an individual neuron can be stimulated by direct heat? Or is it only electricity and light. $\endgroup$ Dec 25, 2022 at 5:51
  • $\begingroup$ @IrvingWashington: Yes, there are neurons which can be stimulated by a small amount of heat; that is how you sense temperature differences. They don't live in the brain. (And one cannot heat up an individual neuron with microwaves; the cellular bodies of neurons are too small to target effectively.) $\endgroup$
    – AlexP
    Dec 25, 2022 at 10:03
  • $\begingroup$ Could a human brain be non-lethally manipulated by an array of overlapping masers (microwave lasers)? "[No.]" +1. Effects of MW on the human brain? Either none or death. Dude's candy bar started to melt standing in front of a radar dish; he was fine and now we have MW ovens. $\endgroup$
    – Mazura
    Dec 26, 2022 at 0:01
8
$\begingroup$

If you replace your microwave lasers with (electric) magnets, then this is something which is actually being used in medical research right now. Transcranial magnetic stimulation can be used to "block" certain regions inside the brain, which is e.g. used to map brain regions before brain surgery.

While it is not known to be possible to create or modify memories or similar things using this technology, it is not completely inconceivable that this or similar technology, when further developed, could "disable" certain parts of the brain or maybe change the structure, which could achieve your desired goals. Some other currently reported side-effects (check the linked wiki article) could also fit to your goals.

$\endgroup$
1
  • $\begingroup$ Thank you! When proposing a sci-fi device, it is alway reasonable to start with what is already under development. I will read up on this as best I’m able. $\endgroup$ Dec 25, 2022 at 6:08
4
$\begingroup$

Already been done, though not with masers proper. You can get your subject to go mad without causing actual physical harm if you are careful enough.

Humans exposed to microwave in a certain way experience the Frey effect:

The microwave auditory effect, also known as the microwave hearing effect or the Frey effect, consists of the human perception of audible clicks, or even speech, induced by pulsed or modulated radio frequencies. The communications are generated directly inside the human head without the need of any receiving electronic device.

And

(...) subjects were discovered to be able to hear appropriately pulsed microwave radiation, from a distance of a few inches to hundreds of feet from the transmitter. In Frey's tests, a repetition rate of 50 Hz was used, with pulse width between 10–70 microseconds. The perceived loudness was found to be linked to the peak power density, instead of average power density. At 1.245 GHz, the peak power density for perception was below 80 mW/cm2. According to Frey, the induced sounds were described as "a buzz, clicking, hiss, or knocking, depending on several transmitter parameters, i.e., pulse width and pulse-repetition rate". By changing transmitter parameters, Frey was able to induce the "perception of severe buffeting of the head, without such apparent vestibular symptoms as dizziness or nausea". Other transmitter parameters induced a pins and needles sensation. Frey experimented with nerve-deaf subjects, and speculated that the human detecting mechanism was in the cochlea, but at the time of the experiment the results were inconclusive due to factors such as tinnitus.

Doing this to someone inside a dome as you suggest may either be science, torture or kinky, depending on how they feel about it.

$\endgroup$
3
  • 2
    $\begingroup$ “may either be science, torture or kinky” as the best of things are, of course. +1 for bringing this to my knowledge, wouldn’t have ever expected it. $\endgroup$
    – Topcode
    Dec 24, 2022 at 23:34
  • 1
    $\begingroup$ "Since the radiation levels approached the (then current) 10 mW/cm² limit of safe exposure, critics have observed that under such conditions brain damage from thermal effects of high power microwave radiation would occur," - a little brann dammae nevr hrut anywho. +3?, ... (50 Hz is radio. But 1.245 GHz is MW) $\endgroup$
    – Mazura
    Dec 26, 2022 at 0:15
  • 1
    $\begingroup$ Torture, on public transportation. Introducing the iPhone 27 : what's a "headphone jack"? ... this thing doesn't even have a speaker! $\endgroup$
    – Mazura
    Dec 26, 2022 at 0:23
3
$\begingroup$

Your setup seems to be a bit like that which is used to treat tumors: an array of x-ray guns are set up in a way that the beams meet at a specific point where their energies add up to a lethal dose to the cells there. Elsewhere the dose remains so low it usually does not do much damage.

Probably masers could be used in the same way, but would they do anything that is purposely wanted without doing any damage? Hard to say, but probably not, they would just heat the tissue, and heat is usually an unwanted effect as the brain works best in constant temperature. Even little overheating can make you dizzy.

However, there might be an alternative way to approach the wanted end result.

What if you change the frequency... a lot. The brain operates on frequencies way way below 1000 Hz, and each frequency band corresponds to specific things going on in the mind? Maybe it could do the trick.

See eg.

https://en.m.wikipedia.org/wiki/Neural_oscillation

$\endgroup$
1
$\begingroup$

Neuron activations are not as regular as interference patterns..

At first glance, your method would be like trying to kill an ant with a machine gun. When the frequency is too high, the regularity of the pattern will affect (fire) too many neurons, resulting in a chaotic (or net zero or headache) response. When the frequency is low, you'll loose resolution.

Electromagnetic fields, even complex interference patterns of fields, have a certain structure. The fields involved in neuronal patterns in the brain are not regular patterns.

There are no standard, or known patters for everyone

We have learned our brain patterns, they differ per individual. You can't "impose" an external field to invoke patterns in biological tissue directly, because you can't predict the result. The patterns (learned patterns) that would yield a correct response could be dynamic and have a very complex structure. For every person, a different, tailor-made field would have to be applied. And it has to be measured and recorded first, with the same person.

$\endgroup$
1
  • $\begingroup$ The neuronal patterns which animate the brain into individual consciousness are certainly incomprehensible to me and I presume far beyond the complete understanding of modern neuroscience. However I would consider fairly accurate modeling of the neuronal pattern “software” on neuron “hardware” a conceivable advance. I find it entirely possible that, within the millennium, a nuanced simulation of human consciousness in brain tissue will be run on a computer. Would you agree that predicting the result of an external stimulus is conceivable from such a vantage? $\endgroup$ Dec 25, 2022 at 6:30
1
$\begingroup$

Human brains are notoriously incomprehensible to science, except at the "big picture" level. Once you start talking about the functions of individual neurons, or trying to achieve any particular effect by tweaking individual neurons or synapses, the current state of the art of neuroscience probably can't help you at all.

So the unrealistic part of your plan is not that masers might be able to manipulate people's brains, but rather that masers or anything else might be able to do so in an intentional, controlled manner. Whether or not the tool would work, nobody knows how to use it.

So the answer is: if you're OK with your story assuming some massive advancements in neuroscience research that would be required for anyone to operate such a device with the kind of outcomes you want, then it's no less believable that the device uses masers vs. any other technobabble. Go ahead and write it with masers if that's what you want. Masers sound cool.

$\endgroup$
1
  • $\begingroup$ Thanks Kaya3! I think there may not yet be specific answers to the questions I have about the theoretical limits of the precision or penetration of masers through tissue, as masers are a relatively new technology. Similarly, experiments as to the effect of such a precise instrument on the neuron are difficult because it doesn't exist. However, the creature using such a device in my story has hit the exponential intelligence growth associated with being able design better brains for oneself, so great leaps in neuroscience fit perfectly! $\endgroup$ Dec 29, 2022 at 6:04

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .