[HN Gopher] Myths about the brain
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Myths about the brain
Author : dnetesn
Score : 85 points
Date : 2021-12-22 11:05 UTC (11 hours ago)
(HTM) web link (nautil.us)
(TXT) w3m dump (nautil.us)
| notfed wrote:
| This article bothers me a little bit. It makes it sound like the
| brain is completely structureless, and that the division of brain
| into "parts" is a myth.
|
| I'm not a neurologist but this seems a disingenuous. Surely we
| know that the limbic system serves a major role in emotions. We
| know that the hippocampus serves a major role in long term memory
| formation. The amygdala controls the fear response. Plenty of
| other examples.
|
| But this article is very high level so maybe I'm completely
| misunderstanding what "myth" they're trying to debunk.
| ziddoap wrote:
| Also not a neurologist, but my reading of it was not the brain
| is "completely structureless" by any means. More that the
| 'structures' aren't clearly defined and, crucially, that the
| 'structures' don't act completely independently from the rest
| of the brain.
|
| _" Pretty much everything that your brain creates, from sights
| and sounds to memories and emotions, _involves your whole
| brain_."_
|
| They briefly mention that our notion of distinct brain
| structures may be influenced by our hyper-focus on certain
| areas of the brain, rather than wholistic study of the brain
| (because it's expensive).
|
| As a kid, I certainly thought each portion of the brain was
| independent. As in, I believed that my motor functions came
| from the clearly distinct "motor function structure" of the
| brain and without that structure, I would have no motor
| function at all (and with no ability to regain motor function).
| I think that is the myth they are referring to.
| neom wrote:
| I think what he's trying to say is that although the brain is
| divided, because consciousness is complex, most neurons are
| involved in most things?
|
| Good conversation: Potential Functional Role for Minicolumns in
| Neocortex - https://www.youtube.com/watch?v=9nEVO22IsVY
| neuroma wrote:
| Agreed. Phrenology was the old hat idea, where names of folk
| psychology concepts were scrawled across areas of cortex.
|
| The brain is specialised and differentiated.
|
| However our concepts of what it does are being refined.
|
| Instead of hunting for "the place where happiness lives",
| imposing ideas from culturally laden folk psychology onto the
| gelatinous mass... we are moving towards more fundamental
| notions of complex nervous system axioms. Like seeking,
| avoidance, arousal, mood, emotional valence, attention.
|
| Brains are fun
| eveningsteps wrote:
| > The third myth is that there's a clear dividing line between
| diseases of the body, such as cardiovascular disease, and
| diseases of the mind, such as depression.
|
| "The Widowmaker", the 15th episode of "Circle of Willis", also
| touches this topic, where heartache and uneasiness may, and often
| do, kill:
| http://circleofwillispodcast.com/episode/3c339c578a884870/th...
| taeric wrote:
| I regret that we have grown to call things like this myths. Seems
| many are then dismissed as false, without retaining any sense of
| usefulness they may or may not have.
|
| Instead, simplifications and the limits of their explanation
| would be a much greater framing for some things.
| wrp wrote:
| The books of William Uttal cover the issues of localization and
| neurological modeling at different levels of detail. The most
| popular I think is _The New Phrenology_ [1] and the most
| technical is _Mind and Brain_ [2]. A quote from the latter:
|
| _To sum up, the new metaphor proposed here asserts that it seems
| more likely in the light of current research that there are no
| demarcatable regions nor any regions of predetermined and fixed
| cognitive functionality in the brain; there are, rather, just
| "softly" bounded areas that may shrink, enlarge, or be recruited
| as the current task demands. Furthermore, none of these weakly
| bounded regions has any specific, preassigned, or fixed function.
| They all serve as general-purpose processing entities as required
| by whatever cognitive task is being processed. The whole notion
| of a place on the brain having a specific identifiable purpose
| has to be abandoned as an unreliable and outmoded metaphor._
|
| [1] https://www.amazon.com/New-Phrenology-Localizing-
| Philosophic...
|
| [2] https://www.amazon.com/Mind-Brain-Appraisal-Cognitive-
| Neuros...
| NikolaNovak wrote:
| I love articles like this. But I have NO facility or background
| to evaluate them. Given their premise is "everything you've been
| told is wrong", how do I know that this one is right? :-/
|
| I just finished Blindsight, which is a SciFi novel but written by
| PhD Biologist and highly respected in Neurological circles...
| which pretty much commits to every.single.one. of these 'myths'.
|
| Note, this is not an issue of "it's a young empirical discipline
| with a lot of uncertainty" (though that is the case as well:).
| For things which we _should_ be able to discern some basic
| patterns and models, there seems to be tremendous amount of
| disagreement in seemingly-authoritative and knowledgeable
| sources; which just allows so much Woo-Hoo of the world to arise
| (and I 'm not _just_ thinking of Deepak Chopra:).
| sowbug wrote:
| If you find the subject interesting and would like to read
| more, I recommend Jeff Hawkins' _A Thousand Brains: A New
| Theory of Intelligence_ , which was released earlier this year
| and covers a theory that a large part of your brain is made of
| 150,000 near-identical subsystems called "cortical columns."
| It's geared toward people who have little background in
| neuroscience. You might also follow up with Anil Seth's
| "controlled hallucination" theory in _Being You: A New Science
| of Consciousness_.
|
| If you prefer to pay for this knowledge with just time rather
| than also money, on YouTube there are three videos from Numenta
| that cover Jeff's book, and then there's a Ted talk by Anil on
| consciousness.
| jasonhansel wrote:
| > Most neurons have multiple jobs, not a single psychological
| purpose. For example, neurons in a brain region called the
| anterior cingulate cortex are regularly involved in memory,
| emotion, decision-making, pain, moral judgments, imagination,
| attention, and empathy.
|
| One possible answer here is that these things (e.g., memory,
| emotion, decision-making, and pain) actually have more in common
| than we perceive. It's possible that mental states that seem very
| different to us (from "inside" our brains) are in fact quite
| similar (from "outside" the brain), or vice versa. The lesson may
| really just be that our own introspection is an unreliable guide
| to the actual structure of the mind.
| ppod wrote:
| I agree with the other comments in here: this article takes
| several complex, long-running debates (modularity vs
| connectionism, predictive vs feedforward processing,
| dualism/monism) and reduces them to simplistic flamebait answers
| that come down definitively on one side. It's really the worst
| kind of popular science writing, because it's overconfident and
| dismissive of the opposing view rather then separating the debate
| out into appropriate parts that can be tackled with evidence-
| based research.
| devindotcom wrote:
| I'm no expert, but this article seems misleading in several ways.
|
| >Myth number one is that specific parts of the human brain have
| specific psychological jobs.
|
| Your brain is both very compartmentalized and generalized. The
| neocortex contains many discrete regions with very specialized
| neural architectures for specific tasks. The visual cortex and
| Broca's Area have specific and very different psychological jobs.
| No one's Broca's Area does edge detection on signals coming from
| the optic nerve, and no one's V1 is contributing to their manner
| of speech. The cerebellum does one thing, the olivary complexes
| another, etc.
|
| Of course there is a huge amount of uncertainty as to what
| various areas do and how they communicate - the brain is an
| amazingly plastic network and as the author points out it can
| reorganize and repurpose quickly, but there are certainly
| specialized areas like "puzzle pieces," just with somewhat fuzzy
| borders to them. The "triune brain" is
|
| >Myth number two is that your brain reacts to events in the
| world... All your neurons are firing at various rates all the
| time.
|
| I don't understand this. Of course your brain reacts to events in
| the world. That is what it is for, to interpret events in the
| world and issue instructions to respond to them. It is true that
| for example the reading portions of your brain are not "off"
| until you open a book, but it's clear that neuronal activity and
| blood flow increases to these areas when a person is engaged in
| the corresponding activity. So it is not a matter of off and on,
| but rather idle and under load.
|
| Prediction is part of this process as well, but it doesn't mean
| that the brain does not respond in a macro or micro way to
| stimuli.
|
| >The third myth is that there's a clear dividing line between
| diseases of the body, such as cardiovascular disease, and
| diseases of the mind, such as depression.
|
| I can see how this might be confusing, but I don't think many
| people take Cartesian Dualism this literally. Maybe I'm wrong.
| People I think generally understand that the brain is an organ,
| part of the body and different from individual to individual.
|
| But what you treat with a serotonin reuptake inhibitor or
| antipsychotic is different from what you treat with therapy. One
| is a treatment for the brain, the organ, the other is a treatment
| for the mind, the abstract concept we have for the sum of our
| learned experiences. These are certainly different things.
|
| I would not go blindly repeating the things this article claims.
| It is mischaracterizing both the myths and the truth, in my
| (amateur) opinion.
| bjornsing wrote:
| > Scientists have believed for a long time that severe damage to
| the visual cortex in the left side of your brain will leave you
| unable to see out of your right eye, assuming that the ability to
| see out of one eye is largely due to the visual cortex on the
| opposite side.
|
| IIRC it's well known that the left hemisphere processes visual
| stimuli from the right field of view of both eyes...
| rikeanimer wrote:
| "Today, we know the brain isn't divided into puzzle pieces with
| dedicated psychological functions. Instead, the human brain is a
| massive network of neurons."
|
| Wow. Speechless. Maybe it's Broca's aphasia?
|
| It's a sad day when nautil.us is publishing stuff like this.
| Sigh.
| jbandela1 wrote:
| I think this article focuses on too much on some nuances of
| neuroscience, that in the end it becomes misleading. I guess a
| similar example would be making a statement like, all programming
| languages are equally useful since they are all Turing complete.
| It has some basis of truth, but is very misleading as in the real
| world, Javascript and QBasic are used in radically different
| ways.
|
| Though I no longer am practicing neurosurgery, I did do 6 years
| of training in neurosurgery and probably treated thousands of
| patients with various brain issues.
|
| So let me give my perspective on the first myth, and if I have
| time may address some of the other ones as well.
|
| > Myth number one is that specific parts of the human brain have
| specific psychological jobs.
|
| What is true is that specific parts of the brain have very
| specific _physiological_ jobs. Psychological function is likely
| complex enough that multiple parts of the brain are involved, but
| there are areas when affected, that can have certain
| psychological effects. Let me give a couple of cases that
| illustrate both the physiological and psychological aspects.
|
| For the physiological case, we had a patient that had seizures
| that could not be treated with medicine, and required some of the
| brain tissue to be removed. Unfortunately, the area was very
| close to the speech areas of the brain. What we ended up doing is
| putting the patient to sleep, opening up the skull and brain
| covering (dura), and then waking the patient back up.
| Neuropsychologists tested the patient's ability to name things
| and speak as we zapped small areas of the brain with electrodes.
| When we hit a critical area, the patient's speech stopped
| instantly. Doing this, we were able to map the speech areas with
| millimeter accuracy so we could safely do the surgery.
|
| In terms of psychological function, it is know that the front
| part of the brain is involved in impulse control. I saw an older
| patient with his family who had a large tumor there. I asked them
| if he had done anything impulsive recently. They had surprised
| looks on their faces as they said, "How did you know?" and then
| related how the man, who had been a very upstanding person all
| his life, had done something that had gotten him arrested.
|
| So I would say, for the general non-specialist, the idea that
| brains have specific parts that do specific things is probably
| less of a myth than some notion of all parts of the brain doing
| everything/most things.
|
| A computer analogy to what the article is doing would be like
| saying that because there is no one specific part of a computer
| that is responsible for playing Youtube videos (the CPU, GPU,
| Memory, SSD, PCI system would all be involved) it is myth that
| computers have specialized parts.
| sabellito wrote:
| Well, the first myth is a complete surprise to me, especially the
| bit about the lizard brain. I've parroted about it in casual
| conversation for decades now.
| mwattsun wrote:
| Like me, you were probably exposed, like most of us, to the
| ideas in Carl Sagan's "The Dragons of Eden" and "Broca's Brain"
|
| _The triune brain hypothesis became familiar to a broad
| popular audience through Carl Sagan 's Pulitzer prize winning
| 1977 book The Dragons of Eden._
|
| https://en.wikipedia.org/wiki/The_Dragons_of_Eden
|
| https://en.wikipedia.org/wiki/Broca%27s_Brain
|
| The other mythical meme of note from those days is that we only
| use 10% of our brain.
| boomboomsubban wrote:
| I thought the "lizard brain" was the part of our nervous system
| that would respond before the actual brain had time to process.
| Like I've heard we'll pull our hand away from a hot pan before
| we feel pain.
|
| Now I both don't know if I've misunderstood peoples references,
| and have no idea if my version of a lizard brain does exist.
| roywiggins wrote:
| Some reflexes do happen before the signals hit the brain,
| they go through the spinal cord and back to your limbs.
|
| https://www.ncbi.nlm.nih.gov/books/NBK544292/
| ppod wrote:
| The article sets up a bit of a straw man (or maybe a motte-and-
| bailey) I think, because it says "all mammal brains (and most
| likely, all vertebrate brains as well) are built from a single
| manufacturing plan using the same kinds of neurons."; but I'm
| not sure that really refutes the notion that most of us have
| when we think of the lizard brain. Ontology doesn't
| recapitulate phylogeny, but we do have a cerebellum, and our
| actions and reactions happen along a broad spectrum of temporal
| control and conscious awareness.
| feoren wrote:
| > [Myth 1] specific parts of the human brain have specific
| psychological jobs ... [Rebuttal] Neurons in a brain region
| called the anterior cingulate cortex are regularly involved in
| memory, emotion, decision-making, pain, moral judgments,
| imagination, attention, and empathy.
|
| This is not a rebuttal to the myth. Imagine I'm talking about a
| car, and I say: It's a myth that specific parts of the car have
| specific functions. For example, the engine is involved in
| starting the car, accelerating the car, decelerating the car,
| regulating the car's speed, producing heat for the cabin, and
| running the alternator to produce electricity for the lights,
| power systems, and radio! That's so many things! But of course
| the engine has one dedicated, primary function, and the others
| are either downstream functions or side benefits. The anterior
| cingulate cortex is clearly not as specialized as a car engine,
| but it _is_ highly specialized; it 's just that its specialized
| function is not so easy to describe (or even discern) in words
| like "memory", "emotion", etc. Each of those words describes a
| huge group of functions that are downstream of the function of
| the anterior cingulate cortex and many other specialized
| structures.
|
| I believe the "specialized brain regions" idea has been over-
| debunked. It was the source of so much woo woo in the late 20th
| century (are you right-brained or left-brained!?) that we've come
| to think it's complete bunk. But we have a huge body of evidence
| showing that there is a big difference in how the left vs. right
| brain processes information and that different brain regions are
| highly specialized, but that their specialized functions don't
| map cleanly into the language we were already describing human
| behavior with.
| treeman79 wrote:
| Suffered some minor strokes. Right left brain stuff was
| interesting. Lost ability to hand write. But could draw fine.
| Right side of body became very weak and numb. Some mental stuff
| was fine. Others were not. Last I looked up it seemed to match
| left and right brain theory. Creative vs math side, etc.
| lr4444lr wrote:
| Fascinating. How is your ability to do math problems? Can you
| do them on paper at least?
| treeman79 wrote:
| All math or programming tasks become oddly hard. Something
| simple that I had done 1000 times before in seconds became
| a week long project.
|
| After I had been on blood thinners for a bit and my mind
| recovers I sat down at a problem that I couldn't figure out
| for six months. 10 minutes later it was done.
|
| Had an ER visit were I was getting all questions wrong.
| Year, president, etc. I knew my answers were wrong. But I
| didn't know why, or what they should be.
| feoren wrote:
| You've probably already heard of Dr. Jill Bolte Taylor, but
| if you haven't, you should look up "My Stroke of Insight".
| The TED talk version is quick and interesting -- she talks
| about exactly this. I'm working through her "Whole Brain
| Living" book and it addresses many of the exact points in
| this Nautilus article, although I can't _resoundingly_
| recommend the book as it has its own flaws.
| cknizek wrote:
| > I believe the "specialized brain regions" idea has been over-
| debunked. It was the source of so much woo woo in the late 20th
| century (are you right-brained or left-brained!?) that we've
| come to think it's complete bunk.
|
| I still see PopSci articles with a title along the lines of;
| "Scientists have discovered the part of the brain responsible
| for X". Even in studies or experiments in the literature, I
| still see color gradient scales used for fMRI. These are
| _known_ to vastly over exaggerate the discrepancy between
| functional areas. And yet they allow for a more easily
| digestible view of what the study is after, which is probably
| why they 're still used.
|
| I think what the author is getting at is that, yes, some parts
| of the brain are more specialized than others. But there is
| _no_ specific part of the brain that regulates a specific
| function and _nothing else_. Rather, it 's an enormously
| complex system.
|
| edit: Color gradient scales are fine for academic studies and
| research. However, they can be misleading to laypeople.
| uniqueuid wrote:
| I think the key here is that some tasks are very clearly
| localized, such as speech in Broca and Wernicke.
|
| But others are not as localized. And functional areas might
| even move during phases of plasticity (i.e. being born blind).
|
| So it seems very clear that some functionally distinct regions
| exist, but researchers still struggle to pinpoint very abstract
| things like memory, personality, and complex behavior.
| TheOtherHobbes wrote:
| Can we be sure what "localised" means in this context?
|
| If you destroy an area and some people lose one particular
| function, while other people only lose small fragments of the
| function - which seems to be true of Broca's region - can the
| function really be said to be localised?
| uniqueuid wrote:
| That's a good question, I'd need to ask a neurologist
| friend of mine.
|
| IIRC there are some areas that are localized almost in the
| sense of a circuit.
|
| Hearing is an example, which needs to process sensory
| information much faster (and more direct) than ordinary
| pathways would, in order to be able to construct spatial
| representation from latency differences.
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