This could imply that (a) the exterior folds are far more important than the inner volume or (b) we shouldn't discount interstitial fluid as being inert with respect to cognition in these cases. Though the absence of lissencephaly cases with normal or above average intelligence (from a cursory search) probably supports the former. The latter would be delightfully weird - but I'm sure there's all kinds of strange and poorly understood things going on your spinal fluid.
(a) is exactly what is described in a paper he linked- the exterior, and more important, gray matter is pretty much all there. The vast majority of what is missing is white matter.
Also, it's fairly reasonable to assume that IQ doesn't scale nearly linearly with brain mass (data on male/female differences clearly shows that a 10% size difference doesn't translate to much of anything on average).
But let's pretend mass difference does simplistically affect neurological computational throughput. Even then, physically larger brain will need longer, more expensive signalling pathways, which can't be entirely free. Also, the larger the animal, the lower the metabolic rate - and translated to a brain with lots of dead weight, that may mean that mass gained via density is at least partially offset by a lower metabolic rate of the tissue (i.e. such a damaged brain may be burning more calories per gram of brain matter left, and that might even be less efficient overal - but in todays society, I think it's safe to say that some hypothetical extra calorie needs wouldn't need to be a problem...)
If you look at it computationally, it's reasonable to assume that many of the "algorithms" the brain uses scale supra-linearly. If you had twice the computing power, the accuracy of the resulting solutions wouldn't be twice as good or arrived at twice as quickly, but some amount much lower than that. To take the classic example of chess; twice the computing power only lets you look ahead a fraction of a move more, not twice as many moves. Furthermore, the brain is a ridiculously parallel computation device. At that scale, it's conceivable that even considerably fewer neurons that operate slightly more quickly (due to a higher metabolic rate and shorter signaling pathways) might perform just as well or even better on certain tasks.
All in all, it doesn't surprise me that a considerable difference in brain mass don't necessarily translate to an easily measurable IQ difference. There's going to be some effect surely, but how large would the mass difference need to be before it's noticeable? I have no idea. And those dramatic images seem to be from http://www.thelancet.com/journals/lancet/article/PIIS0140-67..., that describe a patient with IQ 75 - perhaps still impressive, but also clearly below average.
While "extracorporeal" evokes the supernatural, some scientists have been working on bringing this back to science. The Relativistic Brain Theory is a book by the neuroscientist that built some of the first brain computer interfaces along with a mathematician that worked on the Human Brain Project. It talks about how the magnetic field created by the electrical current in the brain creates some sort of analog computer. It's a very interesting read but I couldn't shake off the feeling that it was somewhat religiously driven.
One of my professors at old University (http://www.dejanrakovic.com/english.html) had a somewhat similar theory about electrical impulses of our brain being able to extend outside of neural pathways into a much wider surrounding space, all based on some advanced quantum physics calculations (frankly, too advanced for me to follow). And yes, he is also heavily inspired by popular religious/metaphysical ideas, but considering his academical background and indisputably huge knowledge, it's an interesting Sci-fi idea, to say the least...
I have a friend working on the Connectome project (http://cbs.fas.harvard.edu/science/connectome-project) who told me last summer that all brain logic happens in the outer millimeter of tissue, everything inside is essentially routing.
I'm summarizing his summary, so I'm certain it's more complex than that, but to a first order approximation, I'd guess your guess is correct!
And so it wouldn't be particularly surprising that someone with cavities in their brain could be smart. One might expect deficiencies of some sort, but one might be speculating; I probably wouldn't bet on it.
Uhm, but why isn't the routing essential for processing? And why is it there in the first place? In other words, why wouldn't evolution eliminate this costly and unnecessary part of the brain?
it was mentioned that the condition develops gradually from the normal brain. So it seems pretty plausible that in some people the brain successfully rewires in parallel with and in response to the development of the condition so that direct white matter connections get functionally replaced by some kind of mesh-style network in the gray matter layer. While this may suggest that typical amount of white matter may be not strictly necessary, the significantly less than 100% success rate of such rewiring may explain why evolution hasn't gone this way .
This is quite unconvincing: the evolutionary advantage of, let's say, all animals the size of lemurs, having human level intelligence is such that pressure to find this rewiring would have been unprecedented.
I think more data and research is needed here. My feeling is that when a few dozen of such cases are closely studied, interesting patterns will emerge.
It is surprising that these cases exhibit high IQ and no immediate signs of dysfunction, but it would be absolutely extraordinary if no patterns of difference vs. typical brain were found at all.
evolutionary trees are littered with branches that have thus far been unable to overcome local maxima-
Our eyes' retinas for instance, have optic nerves that connect on the light sensitive surface, blocking a huge portion of valuable photons, instead of the logical place to connect them- on the REAR of the retina- as squid and octopus retinas have been connected in their completely independent eye evolution.
Once something works "good enough" there's not really any selective pressure to eliminate obvious design flaws if they don't particularly impede reproduction or survival.
I think any supernatural connotations applied to consciousness in this article may be red herrings. In his recently Blindsight novel, Peter Watts argues not just that consciousness might not be a necessity for high-functioning spacefaring life, but that it might be an encumbrance.
>, consciousness does little beyond taking memos from the vastly richer subconcious environment, rubber-stamping
them, and taking the credit for itself. In fact, the nonconscious mind usually works so well on its own that it actually employs a gatekeeper in the anterious cingulate cortex to do nothing but prevent the conscious self from interfering in daily operations (If the rest of your brain were conscious, it would probably regard you as the pointy-haired boss from Dilbert.)
> Certainly, the example of the patient with a 126 point IQ is an outlier
But in this case, one outlier is all you need. If this person really is fully functional by all measures, then that implies whatever is missing in his brain is unnecessary for passing the Turing test.
If all that tissue is not needed, then why did evolution conserve it? It consumes energy, adds size, and increases weight and head size which reduces agility.
I really dislike "Chief Wiggum skepticism" that likes to just hand wave away and cheaply dismiss amazing things that might teach us a lot.
> If all that tissue is not needed, then why did evolution conserve it?
We don't need two kidneys, two lungs, most of our liver, arms, legs, two eyes, ears, etc. These things just make us better at surviving - more likely to make it out of childhood and to an age where we can reproduce. Turns out, we don't quite need all that matter in our heads either, it just makes it more likely we'd survive some traumatic brain injury. If this guy experienced a TBI with this little brain tissue, there's probably no chance of any meaningful recovery left. Meanwhile we see non-diseased brains recover from injuries that look immediately fatal, like having spikes driven completely through skulls.
What we've known is that our bodies are remarkably resilient to many kinds of injuries. This just extends what we know of our resiliency to this class of injury.
It's also important to realize that hydrocephalus like this is a "small damage over time" type of injury usually - this patient didn't go to sleep with most of his brain matter intact and wake up with it gone, it was gradually lost over months or even years during his childhood as csf slowly increased in volume, obliterating cells as it went. His brain was just quick enough at rewiring that it didn't kill him outright or leave him permanently seizing or in a vegetative state (as with the other half of patients with hydrocephalus this bad). We should be studying him to learn why his brain was able to keep up with the strain where others aren't.
Interesting, and I generally agree, but the parent post could easily be interpreted as "there's nothing to see here, we already know everything, so no need to look into it."
>If all that tissue is not needed, then why did evolution conserve it? It consumes energy, adds size, and increases weight and head size which reduces agility.
Because evolution is just survival. Fittest doesn't necessarily mean "best", particularly if we're talking about individuals of the species. What genes live on are what worked well enough to be passed on to offspring and didn't happen to get erased from the gene pool.
Well, we know that the outside of the brain uses more energy (by volume) than the inside. Plus, the evolutionary advantage of the wrinkles in the brain seems to be to increase surface area (of the outside, of course).
Disclaimer: I'm no neuroscientist but I did take an introductory psych course this one time.
Thermal and wire-length constraints drive optimization toward that particular configuration.
For instance if you're going to make a highly connected multiple-cpu computer it helps to keep the wiring as short as possible and the 'hot' parts on the outside (so they can cool). The most striking example of this design is the old CRAY machines.
I want to know if people like this are less susceptible to concussion. If so, and if it's true that there's not necessarily a decrease in ability, it seems like a strictly superior arrangement.
Energy expended by the brain makes up one-fifth of the resting metabolic rate, so if it is largely ornamental (by volume), it is a very expensive ornament.
One possibility is that the mode and requirements of life have changed so quickly over the last few thousand years that the brain's ability to rewire and optimize for changed environment is lagging, and disabling large swathes of it acts as a kind of a shock therapy to rewire the rest of it at fast pace. The implication is that finding a way to gradually disable parts of the brain may force similar rewiring of active parts; at this point the latent part may be re-enabled and may 'learn' from the rewired part. I would volunteer but, uh..
It's a recurring theme in science that the more we know the more we become aware how little we actually understand.
But the brain and it's embedding in the rest of the body and environment raises this phenomenon to a new level.
I think to some extent it shows that considering something to a certain restricted level as true until falsified is a valid approach. Because a lot of the things science is uncovering about our mental capabilities has been postulated for thousands of years by means of introspection and meditation.
Does anyone know whether this is a degenerative disease or a condition one is born with? It's possible the whole brain is necessary for learning, (including learning how to learn more abstract things), but then can be pruned heavily to move information into denser networks.
(Stupid question perhaps, but) have they looked outside the skull? Lots of old brain-like systems are around the spine and other places I hear (guts etc.). Couldn't there be an anomaly that a part of his brain sits somewhere in his chest?
> The point, though, is that under the right conditions, brain damage may paradoxically result in brain enhancement.
Makes me think of one of my favorite stories: 'Understand' by Ted Chiang. In the story, brain-damaged people treated with an experimental drug gain superintelligence.
It reminds me off the difference between a desktop and laptop computer. I've often thought it remarkable with them how you squish the circuitry into about a tenth the volume and get much the same functionality.
Not a very suitable analogy because an animal brain was in fact optimized for mobility for hundreds of millions of years.
The real difference in desktop vs. laptop is lack of optimization for expandability, for use of standardized components, for ease of physical access for upgrades.
Now that I wrote previous paragraph, it leads me to question whether these 'no-brain' cases may be less fit for future rewiring?
For instance, being transplanted in a different culuture, different language, different field e.g. physical work or arts or social work instead of intellectual or from arts of physical work to social or intellectual work?
It's not quite the same thing, as the network is not any denser, it's more efficient. I can't quite find the right metaphor in computing as I imagine the human creators made things pretty efficient even with valves and transistors.
Perhaps a good metaphor would be that of the flow of water in a branching braiding swamp near the coast and the flow of water in a mountain river.
I assume you're referring to this paragraph from the article?
> But maybe the reality is simpler than the fiction. Maybe you don’t have to tweak genes or interface brains with computers to make the next great leap in cognitive evolution. Right now, right here in the real world, the cognitive function of brain tissue can be boosted— without engineering, without augmentation— by literal orders of magnitude. All it takes, apparently, is the right kind of stress. And if the neuroscience community heeds de Oliveira et al‘s clarion call, we may soon know how to apply that stress to order. The singularity might be a lot closer than we think.
