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When Blind People Do Algebra, the Brain's Visual Areas Light Up
- OskarS 10y agoA functional MRI study of 17 people blind since birth found that areas of visual cortex became active when the participants were asked to solve algebra problems, a team from Johns Hopkins reports in the Proceedings of the National Academy of Sciences. Yeah, I'm gonna take this study with a grain of salt. Too many "fMRI studies of 17 people" have turned out to be barely disguised hooey.
- swiley 10y agoAt least their software probably works now.
- irremediable 10y agoJust because the bug was discovered doesn't mean it's been fixed in deployment. ;) Remember, as well, the bug was only half of that paper's findings; they also found fundamental flaws in the method. Besides which, there are widespread methodological flaws that IMO make more difference.
- Ericson2314 10y agoI heard the visual areas were predetermine simply because the oculor nerved terminates there. So if somebody was blind from birth they're claiming that some specialization might be hardcoded after all.
- neolefty 10y agoBiological GPGPU?
- norea-armozel 10y agoSo you're saying we can use blind people for BTC mining? :3 Sorry I couldn't help myself.
- jakub_h 10y agoThat sounds like Audio CAPTCHA.
- recurrent 10y agoThis seems to provide once more evidence for the hypotheses that the cortex implements some sort of general purpose algorithm. The visual cortex of a blind person does not receive any sensory information, but just information from other cortical areas. Perhaps it then simply learns (by reward modulation) to augment the high-order association that occurs in the occipital lobe. Interesting stuff.
- Garlef 10y agoMy guess would be that the yoneda lemma plays a role: The visual interpretation of Hom(-,X) would be roughly 'What are the visual parts of X'.
- aisofteng 10y ago>the cortex implements some kind of general purpose algorithm That algorithm is really just the laws of physics being followed in a very, very complex system. Not to be overly pedantic, but when you say "some sort of general algorithm," what do you mean? Do you mean that there is some sort of information processing in the cortex (everyone's cortex!) that could be written down and named "the process of cognition"? Perhaps by "some sort of general algorithm" you really mean the mechanisms underlying neuroplasticity, which are what enable learning and memory and this arguably the ability to have what we call consciousness? I don't mean to nitpick (and I don't think I am) but this tendency among HN comments to try to shoehorn principles of computing into an alleged understanding of cognition seems to be both popular and, well, unsupported by any existing science.
- rvense 10y agoWhen people see, the brain's algebra area lights up.
- deleted 10y ago[deleted]
- neolefty 10y agoMaybe that explains why I can't see (I bump into things) when I'm doing algebra or other complex logical thinking.
- omginternets 10y agoI suspect that's rather a case of inattentional blindness. https://en.wikipedia.org/wiki/Inattentional_blindness https://en.wikipedia.org/wiki/Inattentional_blindness
- jakub_h 10y agoI call it "the reverse case of ZX-80".
- omginternets 10y agoI get your point but it's absurd to call V1 - V3 an "algebra area". We actually do have a thing called "primary visual cortex" and mental calculations are known to exploit a number of existing functional areas (visual word-form area, primary visual cortex, etc).
- Undertow_ 10y agoI wonder if this would have the same conclusion when they're presented with calculus or other forms of math.
- chestervonwinch 10y agoor if, for example, the fear pathways light up when presented with analysis: "Suppose ε > 0 ..."
- buro9 10y agoJoo Janta 200 Super-Chromatic Calculus Sensitive Sunglasses have been specially designed to help people develop a relaxed attitude to calculus. At the first hint of calculus, they turn totally black and thus prevent you from seeing anything that might alarm you.
- gedankespieler 10y agoIf areas of the brain could have any purpose, why are the same purposes allocated to the same areas in each person? This doesn't make any sense to me. Of course, brains aren't totally uniform, but the fact that you can say "x area is used for y activity in general" seems pretty absurd. Or maybe there is a particular, most efficient arrangement of departments. But surely this can't be achieved in every individual. I wish studies didn't try to be as general sometimes - the anomalies are more interesting.
- jonsen 10y agoFor one sensory input nerves and motor output nerves have distinct entry/exit points. I.e. visual preprocessing must ofcourse take place in the brain where the optical nerves enter.
- aisofteng 10y agoThis is an excellent question, and an unanswered one. I want to add that functional areas of the brain are not 100% consistent and in fact vary not only by handedness but also by enough that a neurosurgeon cannot confidently operate on a specific location of the brain without first verifying what functionality it exhibits. That said, the remarkable consistency of the location of, say, Broca's area, has always baffled me. Human DNA encodes signals that trigger the development of the neural tube and later the nervous system; that much is understandable - but how could it be possibly also encoding enough information to consistently result in similar functionality in similar areas? As someone that has done an undergraduate fellowship in mathematical modeling of plasticity in large neural networks (and thus knows just enough to be confident about being wrong without realizing it), my personal mental model for this is that a functional area arises in an essentially deterministic manner based on its inputs - the auditory nerves, optic nerves, sensory input, and so on; the initial neural network must have no predetermined function and instead must have its functionality arise as a consequence of recurrent associations between input, output, and subsequent input, and so on. That is, if a certain area receives visual input, it will adapt to discriminate details in visual sensory information, and similarly with auditory input, and so on - and eventually the only place that, say, Broca's area for language _could_arise is at the intersection of a particular set of sensory inputs. As I said, this is essentially layman speculation. Furthermore, I try to imagine the computational complexity of demonstrating such determinism using a model, and it is staggering. There are on the order of 10^11 neurons, each of which is not only a very complex biochemical unit on its own but also can be modulated by or modulate up to something like 100,000 other neurons - let alone simulating the input to such a model. It truly is staggering. We know so little, and it isn't even clear where to look to find out what we don't know we don't know.
- cee_el2 10y agoWould it be fair and/or relevant to say that all areas of math can be represented geometrically
- lawpoop 10y agoAs a layperson, I don't know how you could represent infinite sets, unless you just pick a random, finite symbol.
- jonsen 10y agoAny line segment, for example, is an infinite set of points.
- lawpoop 10y agoYes, as a mathematical object, that is true. But any symbol we render in the physical world is going to be finite. Drawing a straight mark and calling it an infinite set of points isn't really different from drawing a sideways 8 and calling it an infinite set. It's a symbol that represents something else.
- nkassis 10y agoCheck out the Riemann sphere https://en.wikipedia.org/wiki/Riemann_sphere https://en.wikipedia.org/wiki/Riemann_sphere I thought it was cool when I first saw it. Infinity in the complex plane is one of the poles.
- thanatropism 10y agoI dunno. There's a lot of conceptual metaphors and sometimes even structure from geometry in higher maths, but this is sometimes very abstract and merely makes reference to non-geometric ideas about geometry previously developed. For example, in the kind of stochastic calculus quant finance people learn, there's an isometry (like a transformation that preserves size in some sense) between two very different kinds of continuous, non-enumerable spaces. Geometric intuition is of no help there -- you did learn what an isometry was in high school so you know the word, but you can't see function spaces in any way, shape or fashion. OTOH what I'm working on for my dissertation is "geometric integrators" for certain kinds of differential equations where the isometries and references to geometry are more direct; basically, the most common numerical solvers for initial value problems in ODEs preserve certain invariants and are useful for many many problems, but sometimes you want computation to preserve some sense of volume -- clasically, in mechanics. So even though many problems are too abstract to be seen, the notion of volume conservation is the best way to acquire the basic notions of the field.
- disc1300 10y agoDidn't even mention if their performance was better/worse. What area of the brain lit up when I read this article? The BS detector...
- mamon 10y agoThere is nothing special about algebra in that regard. Ask blind person to recall some visual memory (from before they went blind, obviously) and the effect is exactly the same. Or ask any healthy person to close one's eyes and do algebra - still the same effect. The point is: our brain does not really tells apart reality from imagination. The same areas are involved in processing real images comming from the eyes, as well as internally "rendered" imaginary images.
- panglott 10y agoThe study examined people blind since birth. But the article doesn't say much about the degree of their visual impairment—there's a big difference even between "no light perception" and "light perception only" (where people can still get visual information useful for orientation), much less higher amounts of vision. If the study was restricted to people with no light perception since birth, that's a very small population, getting a larger sample might be difficult.
- agumonkey 10y agoMaybe what they considered visual includes abstract spatial (mentioned) areas, and abstract distances (n-dimensional differences) are the bread and butter of reflection.
- lotsoflumens 10y agoWhat happens when a dead salmon does algebra?
- veidr 10y agoSee? Offloading computation onto the GPU was inevitable...
- dominotw 10y agoAre we ever going to move past this 'what parts light up' stage of neuroscience? one-trick-pony science.
- DenisM 10y agoIt's a good question, I've been asking that myself. I have recently befriended a post-doc in neuroscience and in one of his lectures he referred to "part of brain lighting up" as a legitimate research method. So it's not pop-science, it's how the actuals science is being done today. The brain is vast in it's complexity, so much so that we don't even grasp the magnitude of the complexity itself. There are between 10^11 and 10^13 neurons, depending on the method of approximation. There are 10^4 dendrites (inputs) to each neuron, and one output (axon). The inputs are analogue and mediated by chemistry. The output is binary, thankfully, however the axon is fairly long and itself can go in/out of order based on certain chemical balance along its entire length. It's a heck of a job.
- brainfire 10y agoThey're working on it- https://www.braininitiative.nih.gov/ https://www.braininitiative.nih.gov/
- omginternets 10y agoThe research community is way past that stage already. This is a journalistic account of a scientific result. It's important to keep that in mind.
- gcr 10y agoDo underused brain areas adapt to different tasks? If so, isn't this an expected result?
- dschiptsov 10y agoThere is an old idea that the visual cortex involved when we visualize past experiences or memorized material. It probably has a recall machinery. With the blind subjects, perhaps, this activity (dealing with abstractions) has been registered as a distinct (due to lack of sensory input), while in the control group it is drowned in the noise of normally functioning visual cortex. So, it is interesting but inconclusive. Also fMRI can't be used as a method of discovery, because it is based on very approximate statistical models. Something is going on there. Well, there always something is going on.
- pygy_ 10y agoAlso, transcranial magnetic stimulation of the visual cortex of blind braille readers makes their fingers tingle.
- moovacha 10y agoThis really doesn't tell us anything. You could instead speculate that what we consider the "Visual Areas" of the brain are more than that. Hence we have been wrong about those parts of the brain.
- ahstro 10y agoDoes this mean that, if blind people take some drug that has an effect on the "visual areas", their math gets screwed up? What if you gave them a - for sighted people - highly visual psychedelic, will their algebra be all weird (or, weird in a different way than it would be for a sighted person)?
- DanBC 10y agoThat's an interesting question. I don't know an answer, but I did find this post about an old experiment: https://mindhacks.com/2009/11/18/do-blind-people-hallucinate-on-lsd/ https://mindhacks.com/2009/11/18/do-blind-people-hallucinate... It's very unlikely that anything similar would be done today.
- aisofteng 10y agoAs someone with a graduate degree in mathematics, I not only find the result with blind people unsurprising but also doubt the veracity of the results with sighted people. Let me elaborate. Pure mathematics, at a high level, seeks for formalize some sort of observable, intuitive behavior in an experientially accessible system and then generalize it to an abstract degree that is no longer anything to do with experience. For example, counting pebbles directly leads to the positive integers, but you can construct the real numbers, almost all of which are uncomputable and/or transcendental, starting entirely from the integers. When doing high school algebra, we are reasoning about quantities and moving them around, so it makes sense that an otherwise underutilized visual cortex would be used for this purpose in a blind person, especially considering that he would need to construct a more elaborate mental model as a consequence of being unable to look at scratch paper. I would not expect a random sample of sighted people to show activation of visual or spatial reasoning areas just because math education is so poor and so many people get through it by memorization rather than employing abstract reasoning skills based on spatial reasoning - in fact, I would expect increased activation of areas related to language. I would expect fMRI imaging of mathematicians, in contrast, to show high activations of areas to do with spatial reasoning, and perhaps even visual processing. See, for example, [1], which provides evidence for this hypothesis. Drawing on personal experience, I learned the basic concepts of linear algebra by direct analogy to three-dimensional visualization, which is of course experientially already present. However, as I progressed and studied n-dimensional vector spaces, I no longer had an experiential analog - and yet I still use some of the same spatial reasoning abstractions (in a different, extended and/or generalized way) when reasoning in the N-dimensional case. My opinion is that this study should have included an experimental group of trained mathematicians (or at least advanced mathematics students with demonstrated mathematical reasoning skills), and I again point to [1] for some degree of justification for this stance. [1] http://m.pnas.org/content/113/18/4909.abstract?sid=fae659df-d2cf-4d4f-bf92-7ed163684721 http://m.pnas.org/content/113/18/4909.abstract?sid=fae659df-...