I have been writing a book for the last eight months ( at the moment I have already written 174 pages ) about anatomically plausible superhumans (a new kind of person who would have to surpass us both intellectually and physically, being smarter and stronger than ordinary people). And at the moment I was interested in what changes in the structure of the human central nervous system could make them smarter (increase their computing abilities, short-term and long-term memory, etc.)?

So, as the most obvious options, I could simply increase the number of neurons themselves; increase their density per cubic centimeter so that we can have more neurons without standing out with a huge head like the satirical Martians, or increase the number of connections per neuron (each neuron in our brain has about 20 thousand connections, which brings the total number of neural connections in the human brain to 100 trillion), but what else would it be necessary to change (add or change) in the human brain to make it smarter?

Note: we are talking only about changes in the structure of the brain itself, everything that concerns the rest of the body, including the circulatory, respiratory and digestive systems, has for the most part already been done.

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    $\begingroup$ Banning smart phones would probably increase average IQ by about 30%-50%. :-) More seriously how do you define "smarter" ? How do you measure "smarter" ? $\endgroup$ Oct 28, 2021 at 18:03
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    $\begingroup$ The question assumes that we know how the human brain works in sufficient detail. We don't. At present, when a pathologist examines a human brain they cannot tell whether the human was smartest, smart, average, dumb or dumbest. And no, the size of the brain is not a good indicator of smartness. $\endgroup$
    – AlexP
    Oct 28, 2021 at 19:13
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    $\begingroup$ Increase of neuron density implies in more sleep time. ncbi.nlm.nih.gov/pmc/articles/PMC4614783 We have 86 billion neurons x 20.000 connection = 1,72 x10^15 connections. $\endgroup$ Oct 28, 2021 at 20:40
  • $\begingroup$ define smarter, a smartphone can calculate way faster than a human brain $\endgroup$
    – John
    Oct 28, 2021 at 20:44
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    $\begingroup$ The only things you have said that are in any way quantifiable are things addressed by using (you should pardon the expression) a smart phone to look up Wikipedia and keep notes. Humans are successful animals because we use tools to augment our abilities. This is easier to do than tinkering with our brains which, you know, is not recommended by the manufacturer (well my mother said it would void my warranty :-) ). $\endgroup$ Oct 28, 2021 at 21:37

8 Answers 8


Enhance the speed

Some measure in brain tissue, like compacting.. or enhancing conductivity between neuron cells.. I have to handwaive the precise method for this, it should be science-based here, and it has never been tried..

But the human brain can certainly be improved regarding speed. Rats and other prey animals do far better in terms of vision speed. They are 2-3 times faster research shows.


For humans, we are a language-using species.. it would be nice if we could shorten our words, to relay much more information in a shorter time. The enhanced brain will be faster too, and be able to work the information and grasp meaning and consequences more quickly.



"Some evidence had suggested that the size of so-called dendrites, the long branched out protrusions through which each neuron receives signals from thousands of other cells, might play a role: Especially in brain areas that integrate different types of information, such as the frontal and temporal lobes, brain cells have bigger dendrites. In these brain areas the cortex, where most of the neurons are, is also thicker in people with higher IQ. Theoretical studies additionally predicted that larger dendrites may help cells to initiate electrical signals faster."



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    $\begingroup$ It's unclear that increasing the speed of computation increases what people call intelligence. It's true that if the only difference between two beings was one of computational speed that we could expect the faster to come up with their genius sooner, but what we call intelligence doesn't seem to be the case of geniuses coming up with correct answers more quickly than dumbies, rather the dumbies come up with wrong answers or none at all. $\endgroup$
    – John O
    Oct 28, 2021 at 19:31
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    $\begingroup$ Agree, it might not affect intelligence, but it would help daily use of the brain.. and also memory (storage) Faster action in the brain can make education much denser, people being able to learn more, quicker.. we actually don't know whether there is a practical limit in containing information. Having a quicker brain will enable us to select and access that information quicker. $\endgroup$
    – Goodies
    Oct 28, 2021 at 19:39
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    $\begingroup$ Could you describe how their brains could work faster than ours? $\endgroup$ Oct 28, 2021 at 21:04
  • $\begingroup$ @FrankThompson4 I'm not an expert on the subject, but there's info available, I added a few links $\endgroup$
    – Goodies
    Oct 29, 2021 at 9:31
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    $\begingroup$ Faster thinking is only made possible through less complex structures which means you can either think smart, or think fast. A rat can think fast because its brain is small, so the path between any 2 points is much shorter. Humans with bigger dendrites than others are following heavily reinforced neuropathways. Our brain reshape itself to make more direct paths for thoughts we have most often, but displace other functionality when we do it. So to be a fast thinker in one way makes you a slower thinker in others. $\endgroup$
    – Nosajimiki
    Nov 1, 2021 at 22:12

For hard-science practical scenarios:

  • check how drugs impact cognitive functions: creatine provides energy to brain cells, caffeine raises attention and decrease reaction time, etc.
  • reduce or limit stress-generating cortisol
  • add extra blood flow for overall performance

Not really fancy, but effective and fully plausible.

  • $\begingroup$ I read a study about modafinil improving memory. But I do not recall the details. Somehow I doubt that bodybuilders who take creatine and drink coffee and tea are smarter than someone who does not. $\endgroup$ Aug 24, 2022 at 5:38

Check out the brainsize to problem-solving ratio of crows compared to humans. If you can take whatever is right about their brain design and scale it up to human size...

Also, any increase in strength or smarts starts with an improvement of the metabolism, heart and lungs.

  • $\begingroup$ We are talking only about changes in the structure of the brain itself, everything that concerns the rest of the body, including the circulatory, respiratory and digestive systems, has for the most part already been done. $\endgroup$ Oct 28, 2021 at 17:36
  • $\begingroup$ Offered what I could. I'm no scientist, so science-based questions tend to go over my head, but maybe one of the big brains on this site actually know what makes a crow's smarts density higher than ours, which will lead to the answer you are seeking. As for the metabolism suggestions that is just an attempt to support believability. $\endgroup$ Oct 28, 2021 at 17:42
  • $\begingroup$ I have already given an option with an increase in the density of neurons, saying that I need something besides this. $\endgroup$ Oct 28, 2021 at 18:07
  • $\begingroup$ I think these responses are always very misleading. A crow is relatively good in problem solving. A human brain has so much more. Multiple languages, understanding of a thousand subcultures, meanings, places and so, so much more. From the most simple things, like seeing a room and knowing what purpose it has, to more complex like pop culture references, to incredibly complex concepts like math or how your TV works. That we're impressed with a few parts of their brain doesn't make their brains superpowered. $\endgroup$
    – Trioxidane
    Oct 28, 2021 at 19:02

Spread the brain and allow willfull suppression of the brain

I have a rather radical suggestion. Spread the brain out over some parts of the body and remove the blood brain barrier. Besides that you can have the brain willfully suppress brain areas, which cause other areas to work better.

Electric interference

In an article I once read they stated that neurons packed together can produce 'neural noise' (a cursory search couldn't produce it, but I'll find it again). This was because too many neurons were packed together. This isn’t a problem for smaller brains, but human brains seemed to approach that limit. The idea is that neurons close to each other can, just by firing their electric potential, cause spontaneous firing of the other. This doesn't happen often and isn't a big problem. Even fully alone a neuron fires once every so often. This is filtered out. It's like receiving morse code and only receiving a single bleep in a day.

The problems start when you bunch them up. If enough are together and are firing, it can cause many neurons to fire spontaneously and more often. Again, the brain is very good at ignoring this noise. Bunch up even more, like in many areas of the human brain and spine, and you can have a lot of noise everywhere. Neurons are generally connected to many others, so each noise signal can be passed down a whole network. If this happens at a large scale the brain receives not just single morse tones but it receives gibberish. Not just on lines that aren't in use, but also lines that are actively sending. That makes processing slower and with faults.

To make the brain better you can spread it. More specifically you spread the brain areas that don't need split second decisions. Moving an arm to catch something must be near instant, planning a complicated move through a room, calculus, predicting what someone will do or complex problem solving tasks don't need this. It'll still be fast from a human perspective. It is only slow in brain terms.

Where to place them? Just behind the ribbs for example. Having several thin layers of brain there will allow them to be sort of safe, as well as insulate them from at least other brain areas. Along the inside of the spine we can add some more. Part of the bones that aren't used for blood or immunity or have other useful functions can be used as well. Moving parts of the connections along the spine can also reduce noise in the connection between the brains. This can cause some problems with ligaments, but I'll let you sort that out.

No blood brain barrier

The brain areas outside the skull are still relatively easily damaged and I suggest to also remove the blood brain barrier. This will make them more susceptible to disease, the immune system and parasites. Yet the advantages can be greater. It takes less energy for them to operate, as no active transport is needed without the blood brain barrier. But more importantly, stem cells and some specific hornones can reach them easily, allowing greater regenerative properties.

That means these areas aren't for (long term) memory. They are purely for their designated task, like calculus. In the likely event some get damaged by anything they reduce or lose their function. Yet this can be regrown and relearned. The superhuman will likely still have most of it's spread brain and it's normal brain, so the loss can be unnoticeable to others. It is a planned way parts of the brain that aren't necessary for survival can be destroyed and regrown, while maintaining maximum functionality and efficiency.


Most of us recall 'one flew over the cuckoo's nest'. Electrical stimulation is used, a reference to what doctors used to do. They effectively destroyed parts of the brain to make people docile. This was later seen as abominable and rejected. Most serious further studies were few and often incredibly careful because of this stigma. Now it starts to see the light again as a wonder 'drug'. It's reducing Parkingson patients their symptoms to close to zero. It appears incredibly effective in some depressed patients.

Most importantly in this story, the TENS method can be used to overstimulate parts of the brain, temporarily shutting them down. If you remember we have a 'creative' side of the brain and a 'calculating' side of the brain we can start to see the advantages. Each brain half is suppressing the other here and there for several reasons. However, if you overstimulate some parts of one brain half, it goes in a sort of low power mode so it can't suppress the other half anymore. You see people suppressing the 'creative' side suddenly exhibiting behaviours of highly intelligent people that are bad at social things. They can draw much better and have better coordination. They can calculate and remember better. The difference is that the people with this treatment are only temporarily this way and can still be social, as they did learn how to do this before the treatment. Some even reported to learn from the experience, saying they could retrieve this state without the treatment and gain some of the advantages.

This is all to say your superhumans should be able to put some parts of the brain in 'low power mode' at will, allowing other brain parts to fully exercise their functions.

normal stuff

Brain is made with a lot of surface area and has a ton of connections. Increasing this can potentially help. During growth there are stages where learning certain skills is easier, which you could trigger on command.


Spreading non essential higher brain functions over the body, in semi protected placed, can reduce neural noise and increase total neuron count. Removing the blood brain barrier can make them regenerate more easily in case of damage and adapt quicker to new situations. Damage is more likely in case of physical damage, bacteria, viruses or chemicals, but the end result can still be a much higher functioning superhuman at most times. Signal time of these higher functioning areas is reduced, but is neither required or noticeable for other people. Temporarily making brain areas barely functioning can make other brain areas function better as suppression is gone. Do this at will.

  • $\begingroup$ How much brain density can be in the head brain without causing issues? With the combo of increased density and spread brain, how much space is reduced in the head brain and how much space is needed in the spine area brain? Give more details on structure and workings there? What issues with ligaments is there? $\endgroup$ Aug 23, 2022 at 18:19

How to increase the size of higher order thinking structures:

When you compare the relative neuron density of humans and birds; you can see that everything that fits inside a human skull could easily be made much smaller and more efficient. Our understanding of bird brains suggests that the human brain could possibly be up to 9 times as space efficient as they are now. So, let's say you can make your super human brain 9 times as space efficient. That means you can take everything the human brain can do right now and make it 1/9th its current size... so, what do you do with all that space you've just freed up, and how does that affect thinking?

The 4 most important parts of the brain worth scaling up are the Frontal Lobe which consists of about 37% of your total brain mass, and the Hippocampus, Broca's area, and Wernicke's area which each represent about 1% of your brain mass each.

So, this means that ~60% of your brain is just lower-level thinking areas that you can leave alone and shrink down to about 7% of your total brain mass.

Improving Speech and Comprehension

Broca's area and Wernicke area are responsible for speech production and comprehension respectively. Scaling these areas up would make your humans capable for far better control over language which would facilitate their ability to learn stuff. With a larger Broca's area you could in theory be much better at speaking multiple languages, and with a larger Wernicke area you could in theory become better at understanding multiple dialects. Or if your super humans have their own language, the combined increase of both would mean that your people could both speak and understand much more subtle phonetic variations than normal humans; so, their language could have far more distinctly understood words without actually needing longer words. So to us normal humans, their language would contain a lot of words that all sound alike, but to them are distinctly different.

"It's Leviosa, Not Leviosaaa!" ~ Hermione (Harry Potter)

The average adult knows about 20,000 active vocabulary words and 40,000 passive vocabulary words and there are about 170,000 total words in the English language. So, lets just say that we keep these at ~1% of your total brain mass, this would give your humans the ability to handle 9 times as much vocabulary, your humans could learn to be totally fluent in the English language being able to recall any word in the dictionary as easily as we can recall the words we use every day, or they could use this extra power to easily become as fluent in 9 different languages as we are in our native language.

At this point you are a fully functional human with advanced language skills, and you are only using up about 9% of your brain cavity.

Improving Analytic Skills and Memorization

The most massive part of your brain to scale up is your frontal lobe. This is where conscious though and executive decision making happens... basically most of the stuff we associate with intelligence happens here. Our Hippocampus is also important to data analysis because it is responsible for holding short-term memory and the allocation of long term memory. In humans this part of the brain is pretty small, but as we scale up the other 3 areas, the natural load on this part of the brain will increase; so, if we want it to handle a bigger load AND provide better short term memory, we need to scale it up more than we will be with other parts of the brain. So for the following statements, let's say that the hippocampus becomes 7% of your total brain mass, and your frontal lobe the remaining 76%.

To measure the effects of this change, the best metric of thinking power is probably how many simultaneous chunks (abstract concepts) your mind can hold onto to at once to work with. The normal mind's consciousness can hold onto a data-set of only 4-9 chucks. Smarter people can cram more inferred information into a chunk, but can generally not exceed these limits. But, your advanced humans could contemplate very complex ideas consisting of 74-166 chucks at once. This means they would have much less need of taking complex problems and breaking them down into smaller, easier to solve issues. This would allow them to instantly recognize complex relationships making them superhumanly intuitive thinkers. It also means that they could split their focus in a lot more ways; so, they could walk into a room and remain "focused" on practically everything around them at once making them exceptional at finding things, practically impossible to sneak up on, and possibly even capable of reading entire paragraphs at a glance since their brain could process the entire meaning of the text in parallel instead of in sequence. Their ability to consider lots of factors together may also make them appear to have powers of precognition. They would not literally see the future, but because they can be aware of so much more of what is going on around them and how this all interconnects, they could recognize much more complex patterns of cause-and-effect than we can. So whereas we may recognize an impending problem right before it comes to fruition, they would notice it the second they walk in the door.

Then you have the Hippocampus. It is responsible for short-term memory and allocation of long term memory. The hippocampus is designed to help you hold onto those 3-7 chucks for 20-30 seconds as you mull them over. But if you are working with 18.5x as many chunks, you also need 18.5x as much short term memory to handle it, but you would also benefit from longer short-term retention. I went with 7% here as the increased load times what it would take to extend short-term to 60-90 seconds, though it is unclear if this is actually a multiplicative issue at all, I would say 7% brain mass would give you at minimum, this much short term memory, but probably much more.

Improving long-term memory

You are probably thinking by now that I forgot to mention what structure you need to improve long-term memory since that is a pretty obvious aspect of intelligence. The reason I have not mentioned a structure for this is because long term memory is evenly distributed throughout the brain; so, it does not matter that much what structures I hypothetically increase. Because this brain is 9 times as dense as a human brain, you should get about 9 times as much storage space.

Is heat dissipation a problem?

Probably not... neurology is analogue, so absolute thresholds can generally be fudged. Our brain often ignores weaker signals not because it can not detect them, but because it chooses not to register the signal as significant. Each synapse uses a Sodium Potassium interchange to create the chemical/electrical pulse that we call a signal. Only when that signal passes its absolute threshold do we "notice" something happening there. But we humans have unnecessarily large brain cells. When you make your brain cells smaller, this does not just mean you can use less space per neuron, but it also means smaller volumes of Sodium and Potassium per synapse. If all of the individual signals in your brain are 9 times weaker, and the brain is trained to be 9 times as sensitive to registering a signal as significant, then you can get 9 times as many signals going at a time without generating any extra heat.

Shortcomings to Consider

Smaller, more sensitive brain cells will probably be more acceptable to trauma and electromagnetic interference. So, while your super humans are REALY smart, they should absolutely not play American Football or go messing around in a fuse box which conflicts with your "physically" superior goals. So while 9x synapses is achievable I would probably scale it back to about 3-5x synapses and use some of that extra space for toughening your brain with things like an organic faraday cage so that they don't get knocked out so easily by a taser and extra impact absorbing fats.

  • $\begingroup$ Can you show how you arrive at the increases of brain power? Especially any articles or other sources? I never received this during my education and I'm mighty curious. $\endgroup$
    – Trioxidane
    Oct 28, 2021 at 22:29
  • $\begingroup$ An excellent answer, how much, in principle, could I increase the density of neurons so that I would not have problems with heat dissipation? $\endgroup$ Oct 29, 2021 at 6:52
  • $\begingroup$ @Trioxidane I've added several links, and further explained how I got to various numbers. $\endgroup$
    – Nosajimiki
    Oct 29, 2021 at 15:39
  • $\begingroup$ @FrankThompson4 Heat dissipation is not a problem. I've added a section to may answer explaining why not. $\endgroup$
    – Nosajimiki
    Oct 29, 2021 at 15:40
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    $\begingroup$ @FrankThompson4 heat dissipation isn't a big problem as far as I know. The brain has a very good vascular network, so the blood can deliver the nutrients as quick as possible. Neurons can't store much energy and still use a lot. That also means the best heat transport is directly available, which is blood. Comparable to a water cooled PC. Each activity also request more blood to the area, increasing the heat transport. The rest of the human body is incredibly well build for heat dissipation compared to other creatures, so you'll likely don't need any change. $\endgroup$
    – Trioxidane
    Oct 31, 2021 at 10:13

Add More Cores and a GPU

Take lessons learned from computer chip designers: Instead of making every processing unit more capable, add more processing units.

e.g. Make the head larger just enough to hold a "third hemisphere" of the brain. Imagine someone with certain types of autism (the ones with huge memories and computational abilities) handled by the two normal hemispheres, but then add a third hemisphere dedicated to handling communications and social interaction. It doesn't need to be as big as the other two.


Human brains are wholly unsuited to optimization regarding superhuman intellectual capacity. Our brains are 3 pound sacks of gelatinous meat that evolution has adapted to do humaning and not much else. Our geometry tends to discourage the sort of optimizations you are after for making Übermenschen, for instance our approximate size means nerve impulses can only move so quickly. It has to remain in a skull, rather than be distributed around the body, etc.

But, perhaps the most damning factor of all is that our software needs to be improved but can't. The corrected software wouldn't run on a meat brain even minimally similar to our own, couldn't be encoded into DNA to be expressed, and probably couldn't cohere into anything like a human personality anyway.

I suggest that your story focus on cybernetic augmentation. It's plausible, if difficult, and would have little trouble enhancing long-term memory (imagine being able to flit through everything you've ever experienced (not just seen, but dreamed or imagined), indexed and searched by any thought or association, at speeds rivaling those of the supercomputers we'll have a century from now). Short-term memory is more challenging still, but still not into the realm of the absurd (people after all write down notes and so forth, though they run they run into issues with managing those past certain scaling limits).

And computing abilities? Imagine having the calculator in your head. Having an IDE in there that auto-builds any algo you can think up and makes the output immediately available. Heck, we almost do something like that now with those smartglasses that Google and Amazon have been tinkering with.

None of this will make the augmentee a genius (or even appreciably smarter than they were before), but it might be what you're looking for.

  • $\begingroup$ I work in the speculative biology genre, so I need answers related to life, not electronics or magic. $\endgroup$ Oct 28, 2021 at 21:07
  • $\begingroup$ @FrankThompson4 The biology is limiting. If you demand that it must be biological and you want it to be even vaguely human, then the answer is "you're trying to fit the square peg into the round hole". $\endgroup$
    – John O
    Oct 28, 2021 at 21:27
  • $\begingroup$ I really dont think you understand the biology? Just imagine if all the superhumans have Einstein&Tesla levels of intelligence. Brains work differently than computers. Yes in pure computing power the computers are superior to humans, but now try to build a brain-sized computer that can move a biped, understand languages, social interactions, do math, grammar, correct translations, drive a car with the biped move set, operate machinery, learn and do an office job etc etc. The full spectrum of a human life cannot be put in a computer yet because we are more than computing power. $\endgroup$
    – Demigan
    Oct 29, 2021 at 10:56
  • $\begingroup$ Also any improvement is good for this answer as long as it is mostly guaranteed to be superior to current brains under the same stimulation and life environment. If you can increase the neuron count without decreasing its capabilities you could have advantages in total computations your brain can make for example. $\endgroup$
    – Demigan
    Oct 29, 2021 at 11:01

Humans cannot be restructured to be smarter. If you change the structure of the brain, your sentient beings are no longer human. They would be a species other than Homo Sapiens.

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    $\begingroup$ This is more like a comment than an answer, and I clearly wrote above that I am talking about a modern Absolutely noaom kind of person. Delete this message. $\endgroup$ Oct 29, 2021 at 6:14

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