Not as exciting when you look at it like that.
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.
I was just about to recommend him to read it. :(
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.
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.
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.
>, 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.)
The Libet experiment
Although it's been meeting some criticism it's still IMO an important experiment with some important findings.
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.
I don't even know what "not necessarily correlated" could mean; perhaps "not deterministic of"?
I really dislike "Chief Wiggum skepticism" that likes to just hand wave away and cheaply dismiss amazing things that might teach us a lot.
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.
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.
Disclaimer: I'm no neuroscientist but I did take an introductory psych course this one time.
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.
White matter (in the inside) is white because is mostly composed by axons, and its function is to connect cellular bodies.
My understanding is that if the external part is not damaged, the processing power should be there.
Of course, that doesn't explain everything, but we don't need to star to believe in souls yet.
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.
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.
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?
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.
> 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.