[HN Gopher] Myths about how the brain works
___________________________________________________________________
Myths about how the brain works
Author : dnetesn
Score : 231 points
Date : 2021-03-04 11:42 UTC (11 hours ago)
(HTM) web link (nautil.us)
(TXT) w3m dump (nautil.us)
| jbandela1 wrote:
| > According to this myth, the brain is like a collection of
| puzzle pieces, each with a dedicated mental function. One puzzle
| piece is for vision, another is for memory, a third is for
| emotions, and so on.
|
| The author makes too much about parts of the brain not being
| specialized.
|
| As a neurosurgery resident in a former life who actually operated
| on brains and took care of people with strokes and trauma, yes,
| different parts of the brain are specialized to do different
| things. Yes, there is plasticity, but there are limits to it,
| especially once you reach adulthood.
|
| I will give some anecdotes, but these are very, very typical.
|
| Example, frontal lobe and impulse control. Saw an older patient
| with a giant tumor in the frontal lobe. His family came with him.
| Seeing where the tumor was, I asked the family if they had
| noticed any recent decline in his impulse control. Their
| response: "Now that you mention it,..." and out came all sorts of
| stories how their previously very proper father, was now doing
| all sorts of very things with very poor judgement and had even
| gotten in trouble with the law. If your frontal lobes get
| damaged, you will have issues with impulse control, long term
| planning, etc.
|
| Another example is speech. Speech is very localized to areas of
| the left brain. As an example, there was patient with seizures in
| the left brain so bad that we would have to remove parts of the
| brain to control them. We did a surgery where we opened up the
| skull, and then woke the patient up. Psychologists asked the
| patient to do various verbal tasks, while we touched different
| parts of the brain with an electrode. When the electrode touched
| the parts of the brain that control speech, the effect was
| instantaneous, the patient suddenly stopped talking mid-word. By
| doing this, were were able to map precisely which parts were
| being used for speech, and in the surgery, avoid those areas. The
| patient had a very good outcome with his seizures stopped, and
| still able to speak.
|
| Another example is movement disorders. Worked with a surgeon who
| is a world class expert in deep brain stimulation. In there you
| precisely place an electrode into a specific part of the brain
| and turn it on. Once you do that, you can have someone with
| severe tremor or Parkinson's who has been unable to even write
| their name for years, suddenly are able to write. You turn off
| the electrode, and the effect goes away. If the electrode is off
| by a millimeter, it does not work. It has to be precisely
| positioned.
|
| In terms of mental illness, I have seen patients with severe
| depression and obsessive, compulsive disorder improve
| significantly after precise placement of an electrode in the
| correct part of the brain.
|
| This thing about parts of the brain specializing is not just
| abstract theory. It is used every day by neurosurgeons,
| neurologists, etc to make life and death decisions. It has a lot
| of real world evidence backing it up. The most important question
| to answer when you see someone with a stroke or brain trauma, is
| "where is it located?" The same size injury can have vastly
| different effects on the person depending on where it is.
| tailspin2019 wrote:
| Thank you.
|
| I'm firmly in the zone of "I don't know what I don't know" when
| it comes to neuroscience but the hard emphasis on the areas of
| the brain not being specialised was in stark contrast to
| literally everything I've read about the brain and neuroscience
| to date.
|
| I wonder if the author is pushing both sides of the coin of
| "myth" and "reality" way to far to the extremes.
|
| I agree with another commenter that perhaps the author is
| trying to push back against older, more rigid ideas of much
| more extreme separation of functions of the brain in a more
| primitive sense.
|
| But some detail is lost here, because as far as I'm concerned
| (and I'm heartened by the support that your more experienced
| and expertise-led comment provides) the brain absolutely and
| demonstrably has specialised areas that focus on certain
| functions.
|
| So in an effort to bust these "myths" I feel parts of this
| article just serve to muddy the water and add some confusion
| rather than clarity.
| wombatmobile wrote:
| Your examples of localised point effects such as speech and
| Parkinsonian tremor responses to probes don't negate the
| article's observation that brain functions are distributed, and
| regions participate in multiple functions.
|
| By way of analogy, you can disable a car sooner or later by
| breaking the ignition switch or the gas tank lid. But those
| points are not alone responsible for the transportation
| function of the car.
|
| The wheels of the car are involved with and vital for
| acceleration, steering, and braking. Without transmission and
| suspension, wheels do none of this.
|
| The transmission of the car is capable of both propulsion and
| braking.
|
| To think of speech as a function of a small part of the left
| side of the brain is incomplete. Speech requires a number of
| motor, sensory, respiratory and data systems to work together
| in a coordinated pipeline that exists across the whole brain
| and body. The neurons involved in those circuits also work to
| perform other functions.
| rnetymtndfn wrote:
| this is more democrat brainwashing - seriously if you are a
| democrat you are a total piece of fucking shit
| frereubu wrote:
| I get the author's beef with the idea that discrete brain areas
| peform discrete tasks - if there's one thing my neuroscience MSc
| taught me it's that the brain processes things in parallel rather
| than series, which is what most of those theories rest on - but I
| think part of the issue is that we try to impose existing words,
| like "memory", onto the brain. One of the more productive lines
| of thinking I used when studying was trying to throw out all of
| those definitions and try to work from first principles about the
| kind of processing various areas were doing. Of course it's
| impossibly complex to get understand it in totality (which is
| probably partially what drives specialising in particular brain
| areas), but discarding the limits imposed by language really
| helped me think more flexibly about what it might be doing.
|
| Also, a small nit about the way it was presented was using
| plasticity (i.e. areas area able to perform different kinds of
| processing if the inputs change, e.g. blindfold + braille) as
| evidence of non-specialisation. That's doesn't follow. Just
| because neurons can be flexible doesn't mean they're not
| performing a discrete task, although I agree with the general
| conclusion.
| nosianu wrote:
| > a small nit about the way it was presented was using
| plasticity ... as evidence of non-specialisation. That's
| doesn't follow.
|
| A small nit about your small nit: The article does not make
| that claim. Quote:
|
| > _I'm not saying that every neuron can do everything, but most
| neurons do more than one thing._
|
| I mean, it's kind of obvious that all neurons are far from
| completely interchangeable, like RAM cells on a memory chip,
| since there clearly is quite a bit of higher level
| architecture.
| frereubu wrote:
| That's different - plasticity shows that neurons can change
| what they do, not that they can do different things at the
| same time.
| imbnwa wrote:
| > I think part of the issue is that we try to impose existing
| words, like "memory", onto the brain
|
| This is also what Freud meant by "time doesn't exist in the
| unconscious". What we call memory isn't discrete like RAM, nor
| is it organized around what we perceive as time, these are
| illusions of how we experience perception and consciousness. He
| described by suggesting we imagine the modern city of Rome,
| then, directly physically overlay ancient Rome on top of modern
| Rome, physics be damned, if an ancient column goes through a
| modern building, then it goes through the modern building
| _without destroying it_ , directly occupying the same space at
| the, er, same time
| [deleted]
| markus_zhang wrote:
| >Brains, however, don't work by stimulus and response. All your
| neurons are firing at various rates all the time. What are they
| doing? Busily making predictions.
|
| Is this a polling system...
|
| Oh actually more like a branch predicting system...
| killtimeatwork wrote:
| > The 21st century is a time of great scientific discovery. Cars
| are driving themselves.
|
| These are the first two sentences of the article and already I'm
| skeptical. I'd say the self-driving cars are mostly a product of
| recent technical inventions and not scientific discovery - the
| scientific discovery happened mostly in the XX century, with
| discoveries which made integrated circuits, or lasers (for lidar)
| possible.
|
| The deep learning concept itself did not "discover" anything,
| it's just a technical contraption that happens to work well for
| some classes of real-world problems. Granted, there were some
| maths advances in the eighties and nineties that made current
| SLAM possible, but again, new math is not "scientific discovery".
| davegauer wrote:
| I completely agree with you and I don't think it's being
| pedantic at all. Clearly the 21st century is bearing the FRUIT
| of scientific discovery and we're seeing incredible iteration
| and innovation that is very exciting. But much of this is the
| result of things which were DISCOVERED in the 20th century.
|
| Language is important. "Discovery" means something just as
| "inventing" means something. I see these words used all the
| time for things like websites (Facebook/Twitter) or computer
| hardware (Apple products most notoriously). Something can be a
| wonderful and very popular implementation without being either
| a discovery or an invention. Often these larger things DO
| contain many smaller real discoveries and inventions along the
| way! But people always seem to be referring to the end product
| as a whole, which I find bizarre.
| ad404b8a372f2b9 wrote:
| Wish someone had told me that I wasn't doing real science
| before I started in academia, would have saved me a lot of time
| and effort. On a more serious note, seems like weird
| gatekeeping of what constitutes scientific discovery and what
| doesn't.
| killtimeatwork wrote:
| Scientific discovery is learning new facts about the world.
| Inventing new contraptions to help us in our goals is
| technology. I.e. I don't think anyone would call Henry Ford a
| scientist or Albert Einstein an inventor. I thought it's
| basic and well-understood distinction.
| beaconstudios wrote:
| If you follow the constructivist philosophy of science
| (spoiler alert: I do) then absolutely Albert Einstein is an
| inventor. He invented a mental model (essentially a lossy
| compression) of some parts of reality that better fit
| observed phenomena than its predecessor. Our
| mental/scientific models are not descriptions of reality;
| objective reality is unknowable. What they are, are tools
| (technologies!) that we can use to predict effect, given a
| cause and a state.
| benlivengood wrote:
| Is constructivist philosophy of science an independent
| axiom or does it have testable predictions? E.g. is there
| a function from theorems of ZFC to {invented, not
| invented}?
| beaconstudios wrote:
| it's a philosophy, so no it doesn't have testable
| predictions - but neither does objectivism, its
| counterpart. But then, testable predictions don't tell
| you about the nature of reality so c'est la vie.
|
| > is there a function from theorems of ZFC to {invented,
| not invented}?
|
| Can you derive definitions of inventions versus
| discoveries from set theory? No, probably not. You can't
| derive the smell of a rose from set theory either though
| so it's probably not a very good theory of everything.
| chaosite wrote:
| You're being overly pedantic over the exact difference between
| "scientific discovery" and "technical invention", a discussion
| which is completely irrelevant to the article.
|
| That line isn't even important to the article, it's just a bit
| of flowery language intended to frame the subject of myth vs.
| fact.
| zaik wrote:
| Besides that, much academic work has to be done before the
| industry can use those ideas to achieve said technological
| advances.
| earthboundkid wrote:
| Okay, but pedantry aside, the 20th century kicked the 21st
| century's ass when it comes to scientific discovery. Some
| stuff discovered between 1900 and 1920:
|
| - Relativity
|
| - Atomic nuclei
|
| - Darwinian modern synthesis
|
| On the technological application side, there was the airplane
| and mass production of cars, plus the growth of telephony and
| radio.
|
| In the 21st century we have:
|
| - found a bunch of extra solar planets but the work really
| started in the 90s, lol
|
| On the application side, we have the cellphone/smartphone
| revolution and continued penetration of the internet, plus
| consumer EVs and solar panels. Not nothing, but the
| smartphone is the biggest change to daily life. Everything
| else is more just refinement of what came before.
|
| I can't really think of other things that are profound
| scientific discoveries versus technical applications or
| filling in of minute details. We're just clearly in the far
| side of the S curve now, and the 20th century was the
| rollercoaster.
| Issaclabs wrote:
| I feel like it was greatly due to the WWII. Those and so
| many other discoveries were the direct result of programs
| like project manhattan. Maybe the human species really
| needs to be pushed to extinction to further txhe human
| enterprise or maybe it was just the crazy funding similar
| to bell labs.
| earthboundkid wrote:
| My comparison period was 1900 to 1920.
| Qwertious wrote:
| >In the 21st century we have:
|
| In much the same way that much of 2020's progress was
| actually started from the 20th century, much of e.g. the
| year 2060's progress will be stuff actually started from
| 2020. We likely systemically underestimate the use of
| today's discoveries simply since the big stuff mostly isn't
| useful yet.
| earthboundkid wrote:
| I agree that we still don't totally know what happened
| 2000-2020, but e.g. the Eddington eclipse proof of
| relativity was 1919 and Einstein became an international
| celebrity around then.
|
| I think I am underrated some math discoveries since it's
| not an area I follow, e.g. the Poincare conjecture proof
| is probably a big deal. On the other hand, when did
| Poincare make his conjecture? 1900. So in a certain
| sense, we are backfilling a known gap.
| killtimeatwork wrote:
| I'd just expect an author to be precise when writing
| something that will be read by thousands of people, as
| opposing to just spitting out some flowery language.
| pattt wrote:
| I'm not somebody well informed about neuroscience hence apologies
| if I'm implying something that's against the common knowledge in
| your domain. One impression upon reading articles like these
| seems to be that there's a lot of research and curiosity about
| the way brain works together but the core model of "brain is
| composed of communicating neurons" seems to be generally
| accepted. Does that suggest that we already understand how a
| single neuron behaves in isolation? I'm mainly interested in the
| microscale model from the perspective of simulation, for example
| in the Wiki page of the Human Brain Project
| (https://en.wikipedia.org/wiki/Human_Brain_Project) among the
| obstacles it's mentioned that "detailed neuron representations
| are very computationally expensive", does it mean that we already
| cracked the microscale, i.e., defined exactly how a neuron
| behaves in a computational (mathematical) model? Perhaps the
| substantial intricacies of the brain can also arise in the
| microscale level depending on cellular mechanisms, nutrition and
| other side effects?
| 40four wrote:
| Great article, as usual from Nautilus!
|
| I would like to add one more myth the list. The idea that we all
| have a finite amount of brains cells.
|
| They used to teach that we're all born with a certain amount of
| brain cells, and over time from aging, or getting a concussion,
| or if you 'do drugs', you would lose said cells. And that's that.
| No more new brain cells :)
|
| We know this to be false now. I don't know how much this one has
| persisted, I haven't heard it in a while. But it was drilled into
| my head as a kid.
|
| Not related to brains, but another health myth that comes to mind
| is the idea that our tounges & taste buds are divided into
| 'zones' that perceive the different flavors. I don't remember the
| order, but something like the tip tastes sweet, the middle is
| umami, the sides are sour, et cetera.
|
| Now we understand all taste buds taste all flavors. Is is
| interesting these old models science came up with to try to
| explain things, and how long some of them persisted.
|
| PS: Check out the 2002 album 'Phrenology' by the Roots. It's a
| classic!
| devindotcom wrote:
| I believe there is at least one prominent exception in the hair
| cells in the inner ear. These are not replaced once they
| rupture - producing the distinctive tinnitus sound at the
| frequency they monitor. Or perhaps I'm mistaken in this -- it's
| been a while since my studies!
| abellerose wrote:
| Do you have links to share for what you're claiming is now
| false? I haven't seen any conclusive evidence yet for what
| you're claiming.
| [deleted]
| EamonnMR wrote:
| While it's not a fixed function pipeline, there is some level of
| correlation between 'brain damage at site x' and 'effect y' so
| while phrenology is bunk, the brain is also not just a blob of
| compute.
| harshreality wrote:
| I don't want to be too critical, because I've learned a lot from
| the author's books, but a fair amount of the article (mainly
| myths 1 and 2) seem to be over-generalization or skewed based on
| the author's bias. Her field is psychology, not primarily
| neuroscience; specifically, the psychology (and some neuroscience
| of) emotion. I recommend Jeff Hawkins's new book for a
| perspective closer to a neuroscientist's. (He's technically not a
| neuroscience Ph.D., but he has equivalent knowledge.)
|
| Myth #1: Brain areas aren't separate and didn't evolve in stages.
|
| 1. _Brain (neocortex) areas aren 't single-purpose._ Obviously
| neuroplasticity is a thing, but the article ignores that areas of
| the brain develop to be _focused_ on a single category of tasks
| (visual, auditory, etc.). The author 's example, blindfolding
| someone and watching their visual cortex get repurposed when
| learning to read braille, ignores that if you _don 't_ blindfold
| them, other areas will probably take up most of the task of
| learning braille because it's _not a visual activity_ and the
| brain tends to separate areas of responsibility.
|
| 2. The number of significant evolutionary steps may not be just
| three, so the triune brain theory may be technically false, but
| I've never seen any actual neuroscientist argue that it isn't
| roughly accurate. The evidence in the article is molecular
| genetics: the fact that there aren't radically different kinds of
| neurons. This is like scaling up an argument that ethanol and
| glucose are the same thing because they share the same elements.
| If the limbic system and neocortex have roughly the same kind of
| neurons, what does that matter? We know they serve radically
| different purposes, and we know that reptiles don't have a
| neocortex (at least, nothing of significance).
|
| Myth #2: Brain is stimulus/response machine
|
| Her argument against this myth seems tortured. Of course the
| brain is not a _simple_ impulse /response machine, but it's still
| essentially taking in inputs and responding in various ways. It
| just has a mind-bogglingly complex internal state.
|
| Myth #3: Strong dividing line between diseases of the brain and
| body
|
| Everything seems to point to her being right on this one. Science
| knows, nearly as much as it can know anything, that neurological
| stress leads to physical stress responses which can screw up
| other parts of the body, often through hormone dysregulation.
| Similarly, physical problems from gut health to inflammation can
| trigger immune responses or simpler biochemical reactions that
| have neurological side-effects. And, of course, diet.
| Psychoactive drugs are a clear example of how an external
| physical influence can have psychological effects.
| jessriedel wrote:
| Excellent comment overall. One quibble:
|
| > Myth #3: Strong dividing line between diseases of the brain
| and body
|
| > Everything seems to point to her being right on this one.
|
| The problem is that most of the time people debunk this "myth"
| they are using some motte-and-bailey tricks.
|
| First, there is no perfect dividing line between disease of the
| brain and body, but there is also no perfect dividing line
| between diseases of the brain and _differences_ of the brain
| (do domestic abusers have bad character or a disease?) or
| between diseases of different organs. Nevertheless, it is
| highly useful to have a taxonomy of phenomena that cuts reality
| roughly at its joints. These divisions have important practical
| and moral implications, and they fact that there are gray areas
| does not mean the categories should be undermined.
|
| Second, these seemingly scientific "there is no line" arguments
| are almost always used asymmetrically by experts to advance a
| normative position, e.g., my psychological disease should be
| treated like a physiological disease by the law and my friends
| because there is no perfect distinction between the
| psychological and physical. It is possible to go in the other
| direction and argue that many/most alleged psychological
| diseases are really just different _preferences_ and should be
| treated as such; see Thomas Szasz:
|
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5353517/
|
| This is just as well supported by "there is no line" argument
| as folks who want physiological-psychological disease equality.
| The reason the latter position is more popularly is based on
| values.
| SkyBelow wrote:
| I was originally against the authors take on Myth one as well,
| but then I considered that my perspective may have been
| somewhat different from the one they were actually talking
| about and I sort of incorrectly translated it. Maybe they were
| speaking directly against a much more harsh version of the
| 'each part of the brain does one thing' than we interpret it.
| Not as a 'the visual cortex handles most of our conscious
| sight' but 'the visual cortex only handles sight and all sight
| is handled by the visual cortex only'. That is much stricter
| and much quickly disproven. As someone with an interest in
| neuroscience, I have long since been exposed to evidence that
| would prevent me from ever considering the second idea as being
| the possible answer, but perhaps others have not. If we
| consider someone who has myths on how the brain works but has
| never taken as much as an intro psychology class and instead
| bases their opinion on what they hear in passing from others,
| such as news sources or daily talk shows, then it is possible
| some people have the second idea as their mental model for the
| brain.
|
| If that is the case, then I do think the author has made a
| slight blunder because the audience who would read their
| article is unlikely to include significant portions of people
| who would've lacked the exposure needed to have that much
| stricter and more incorrect mental model, and thus the author
| could've done better to present the myth so as to not confuse
| it with the not as incorrect mental model of the brain that
| their likely readers have.
| tailspin2019 wrote:
| Completely agree
| benlivengood wrote:
| > Her argument against this myth seems tortured. Of course the
| brain is not a simple impulse/response machine, but it's still
| essentially taking in inputs and responding in various ways. It
| just has a mind-bogglingly complex internal state.
|
| The author was dispelling the myth that a significant fraction
| (or all) of neural activity happens between the time of the
| stimulus and time of the response, which is probably a common
| misperception.
| neilpanchal wrote:
| Highly recommend the MIT course on the human brain if you have
| the time, absolutely amazing:
| https://news.ycombinator.com/item?id=17216634
| narrator wrote:
| I love the twitter account of Neuroskeptic. He makes fun of all
| the asinine stuff people say about the brain:
|
| https://twitter.com/Neuro_Skeptic
| happy-go-lucky wrote:
| I'm no expert at all on neuroscience, but when I recently got the
| opportunity to read a transcript of the lecture titled _The Value
| of Science_ by Richard Feynman, it filled me with awe and
| reverence. I can 't but share a sizable quote from the same.
|
| https://calteches.library.caltech.edu/1575/1/Science.pdf
|
| "For instance, the scientific article may say, 'The radioactive
| phosphorus content of the cerebrum of the rat decreases to one-
| half in a period of two weeks.' Now what does that mean? It means
| that phosphorus that is in the brain of a rat--and also in mine,
| and yours--is not the same phosphorus as it was two weeks ago. It
| means the atoms that are in the brain are being replaced: the
| ones that were there before have gone away. So what is this mind
| of ours: what are these atoms with consciousness? Last week's
| potatoes! They now can remember what was going on in my mind a
| year ago--a mind which has long ago been replaced. To note that
| the thing I call my individuality is only a pattern or dance,
| that is what it means when one discovers how long it takes for
| the atoms of the brain to be replaced by other atoms. The atoms
| come into my brain, dance a dance, and then go out--there are
| always new atoms, but always doing the same dance, remembering
| what the dance was yesterday."
| infogulch wrote:
| I recall some debate around the oldest buildings, and how (I
| think) the Ise Grand Shrine [1] is disqualified because it is
| rebuilt regularly -- for the past 2000 years. Of course, one
| may resolve this by more carefully defining "oldest building",
| but this quote by Feynman makes me lean towards a definition
| that includes this shrine. Who are we to say that some building
| is different because the atoms of its beams came from different
| trees, and in the same breath claim individual continuity
| across decades in the face of this fact about our brain?
|
| https://en.m.wikipedia.org/wiki/Ise_Grand_Shrine
| wilburTheDog wrote:
| The question has been debated longer than the shrine has been
| around. See: Ship of Theseus.
| Geee wrote:
| I wouldn't say that the Triune brain theory is a 'myth'. It's
| just not accurate, but it's not a complete lie either. There
| certainly are different parts of the brain that have evolved at
| different times, and have different functions.
|
| The older parts have evolved to specific functions, while
| neocortex, which is found in mammals, has a uniform structure and
| is capable of learning and adapting to different tasks. 75% of
| human brain is neocortex.
|
| Jeff Hawkings explains the difference between the 'old parts' and
| 'new parts' pretty well in this interview:
| https://www.youtube.com/watch?v=-EVqrDlAqYo&t=366s
| ksm1717 wrote:
| Yea, I think that in some ways the "myths" presented can be
| seen as abstractions that lack details for the sake of being
| digestible. It is also a fair point that these abstractions can
| be poorly carried to detailed conclusions like the example of
| humans being essentially more evolved; I think that's the bone
| to pick
| tgv wrote:
| Brodmann distinguishes 47 or so different areas in the cortex.
| Idk how many are exclusive to the neocortex, but it's not a
| uniform structure.
| cbsmith wrote:
| The article also has this weird notion that the only source of
| evidence of the Triune brain theory are brain scans. We also
| have evidence Wilder Penfield's work stimulating parts of the
| brain. We also have evidence from _damage_ to the brain, from
| physical injury, lesions, tumors, surgeries, strokes, etc.
|
| While that data shows that brain functions aren't strictly
| fixed and neuroplasticity is a thing, it does show that
| locations in the brain do have disproportionate impact on
| certain functions.
| orhmeh09 wrote:
| Barrett's views are not the only ones there are, and they are
| still debated in the field, however much she may insist to the
| media that her view is the only correct one and that all else
| are myths. Things are not nearly as settled as she claims.
| Panksepp, J. (2007). Neurologizing the Psychology of Affects:
| How Appraisal-Based Constructivism and Basic Emotion Theory Can
| Coexist. Perspectives on Psychological Science, 2(3), 281-296.
| https://doi.org/10.1111/j.1745-6916.2007.00045.x
| Panksepp, J. (2008). Cognitive Conceptualism--Where Have All
| the Affects Gone? Additional Corrections for Barrett et al.
| (2007). Perspectives on Psychological Science, 3(4), 305-308.
| https://doi.org/10.1111/j.1745-6924.2008.00081.x
| toolslive wrote:
| obviously, Jerry Fodor was wrong. But anyone who studies
| cognitive science still gets this stuff shoved down his throat.
| The followers will however claim there's a difference between the
| brain and the mind.
|
| from Wikipedia: "For Fodor, significant parts of the mind, such
| as perceptual and linguistic processes, are structured in terms
| of modules, or "organs", which he defines by their causal and
| functional roles. These modules are relatively independent of
| each other and of the "central processing" part of the mind,
| which has a more global and less "domain specific" character.
| Fodor suggests that the character of these modules permits the
| possibility of causal relations with external objects. This, in
| turn, makes it possible for mental states to have contents that
| are about things in the world. The central processing part, on
| the other hand, takes care of the logical relations between the
| various contents and inputs and outputs"
| MrDrDr wrote:
| There are lots of popular tropes of how our brain works and I'd
| agree with this author that they are oversimplified and generally
| incorrect - I'd add the left brain right brain divide to the
| list. However the author appears to be arguing from a position
| that they (or someone) actually know how the brain works - having
| done a neuroscience degree, my one take home was that when it
| comes to modelling the brain against our conscious experience -
| we really don't know anything.
| the__alchemist wrote:
| I had the same reaction to parts. This in particular:
|
| > So why does the myth of a compartmentalized brain persist?
| One reason is that brain-scanning studies are expensive. As a
| compromise, typical studies include only enough scanning to
| show the strongest, most robust brain activity. These
| underpowered studies produce pretty pictures that appear to
| show little islands of activity in a calm-looking brain. But
| they miss plenty of other, less robust activity that may still
| be psychologically and biologically meaningful. In contrast,
| when studies are run with enough power, they show activity in
| the majority of the brain.
|
| Another, more relevant reason, is that brain-scanning studies
| are in their infancy.
| jonnycomputer wrote:
| All of this seems really confused to me, or so simplified
| that it no longer makes any sense.
|
| The simplest thing you can do in a scanner is have them sit
| there doing nothing while you acquire scans. In the end, you
| just have a 4d matrix of unsigned integers. For each voxel
| you can acquire an average over the scan and check whether it
| is significantly above zero using a t-test. Given enough data
| everything will be significantly greater than zero, including
| parts outside the head. Or you can compute a global mean to
| center all the voxles, and check which parts of the brain are
| significantly above the average, or significantly below the
| average. Extremely simple analyses (and so yes, there are
| lots more you could do).
|
| In task fMRI, you have them do a task, and you use events in
| your task design as predictors of the BOLD, and then display
| a voxel map of either the beta values, or, more commonly, the
| T-values of those regression betas (or a contrast of those
| regression betas). In this case, you really aren't looking at
| activity. You are looking at correlations.
|
| Those _islands_ of activity in whole-brain analysis images in
| figures in papers happen because the result images are
| thresholded, e.g. at p < .05 false-discovery-rate correction
| for multiple comparisons. Personally, I think unthresholded
| images are better because they are more informative.
|
| Let's take a concrete example. You have a subject do a task
| where they have to choose between two gambles varying in risk
| and reward. Then, for each voxel, you predict the BOLD time
| course using a series of events (time of presentation of
| gamble options) with magnitude equal to the coefficient of
| variation between the two gambles. So now, for each voxel you
| have a beta value showing how CoV predicts BOLD. You notice
| that anterior insula on both cases has the highest beta
| values. You threshold at conventional statistical
| signficance, after correcting for multiple comparions, and
| all the spurious, or less important, correlations drop out of
| the image, and you are left with two bright spots on a map
| pin-pointed on the left and right anterior insula. See: in
| this anaylysis, not all "psychologically and biolotically
| meaninful activity" is being examined or looked at. For
| example, button presses events show up localized in the motor
| areas too, but they weren't looking at those. But they could
| have, if we were interested.
| Retric wrote:
| The issue here is the brain of test subjects aren't simply
| doing exactly one thing at a time. Your ears don't turn off
| because you're doing a memory task in an MRI.
|
| As such it's impossible to say what subset of brain activity
| is directly related to some activity rather than some related
| mental processes.
| jonnycomputer wrote:
| The brain is doing multiple things at once. But that
| doesn't mean its impossible to subset brain activity
| related to specific activities.
| nvrspyx wrote:
| Not necessarily. For one, most fMRI studies will have a
| resting state scan to establish a baseline of what an
| individual's brain is doing in an MRI setting when it's not
| really doing anything in particular (typically having the
| subject stare at a fixation cross and letting their mind
| freely wander). Then, for the actual task, stimuli are
| presented and responses are recorded at very specific times
| with that fixation cross in between with enough time for
| the brain activity to return to that resting "baseline"
| before the next stimuli.
|
| There's a lot of signal processing theory, regression
| analysis, etc. that goes in to it. With that said, the
| issue that arises is that only the strongest correlates may
| surface or be observed. There may be a lot of brain
| activity that overlaps or looks identical between that
| resting state (baseline) and the stimulation state, but
| can't really be included because a distinction can't be
| made, which goes back to your final point. That, however,
| doesn't mean that there aren't actual subsets of brain
| activity that we can attribute to a specific activity.
|
| For example, if you're in an fMRI and I show you nothing
| but a fixation cross, then show you a sad image at a
| specific time for a specific interval, then went back to
| the fixation cross, and also showed you a scrambled version
| of that same image, I can (oversimplified) run a diff check
| to see what's different between the three. From there, I
| can remove the overlap between the three from normal
| baseline activity and activity specifically related to
| visual processing (scrambled image) to reveal what's
| specifically different with that sad image. If I see that
| the amygdala has much higher activity during that sad image
| compared to the fixation cross and the scrambled image, I
| can conclude that it has some role in emotional processing
| (well not really in this example because you'd also need a
| ton of images, including neutral images, with different
| orderings of each to really be confident; also really
| couldn't make that conclusion, just present the correlation
| because...science).
|
| The point is that there are methods to isolate activity
| related to a specific activity/stimuli/response/etc.
| However, it's currently very difficult, if not impossible,
| to make distinctions in those overlapped areas.
|
| Note: this is obviously an oversimplification of
| neuroimaging research and analysis
| [deleted]
| meepmorp wrote:
| I don't think your point is more relevant than theirs.
|
| It's expensive to run brain scanning studies, so studies have
| smaller populations or lower resolution data collection in
| response. Yes, brain scanning studies are new, but we've been
| doing fMRI studies for nearly 3 decades and it's still
| expensive. Had that cost been scaled back, we'd have more
| and/or better data because grants are (very) finite.
| dr_dshiv wrote:
| Left/right divide is a myth-myth. Check out "Master and His
| Emissary" for the enormous amount of evidence about left/right
| divide.
|
| The mirror neuron system is also a myth-myth. While there
| aren't "mirror neurons", per se (e.g., biochemically
| different), there is a system of mirroring and it is very
| important
| caddemon wrote:
| I think there are a lot of myth-myths where basically the
| general public ran with a wildly pseudoscientific
| interpretation, and then the scientific community decides to
| dismiss the entire thing (at least outside of whatever
| subfield, although I've sometimes seen it within too).
|
| Speaking specifically to left vs right brain, in popular
| media I've mostly seen it presented as logic vs creativity,
| which completely disregards that people can be creative
| verbally, and that certain quantitative/technical things are
| very non-verbal.
| Blikkentrekker wrote:
| What surprised me most about the replication crisis was that
| neurology actually seemed to be more affected than psychology
| in how non-reproducible it was.
| ianhanschen wrote:
| I'm upvoting your comment but can you clarify on left
| brain/right brain? I thought split-brain/callosal syndrome
| showed us that a lot of our ideas about left brain right brain
| functional divide were true.
|
| Edit for clarification: I was not expecting folks to respond to
| this by linking split-brain experiments; I am specifically
| referring to split-brain experiments showing us that our ideas
| about left brain/right brain were correct. This was in reply to
| "I'd agree with this author that they are oversimplified and
| generally incorrect - I'd add the left brain right brain divide
| to the list" -- I want to know what this person thinks, thanks.
| armoredkitten wrote:
| My best understanding (which, it's been a while since I took
| classes about it) is that there are some functions that tend
| to be more lateralized to one hemisphere or another -- with
| language being the prime example. However, some people do
| show more balanced functioning, and in some cases (more
| frequently among left-handed people) the lateralized
| functions can even be flipped from "normal".
|
| However, there's left-brain/right-brain in terms of "some
| functions of the brain tend to be more on one side or
| another", and then there's left-brain/right-brain in terms of
| a pseudoscientific personality test about whether you're more
| of a "logical" thinker or "artistic" thinker, blah blah blah.
| There's no evidence for that. It's just mumbo-jumbo Buzzfeed-
| style quizzes to make you feel good about yourself.
| bregma wrote:
| More accurately, in right-handed populations subjects there
| is good correlation between localized brain insults and
| specific functional deficits. The association between brain
| insult locations and specific functional deficits is less
| strongly correlated in left-handed people and certain other
| subpopulations. These are also very much tendencies and not
| predictors for individuals.
| ianhanschen wrote:
| aha, thanks!
| sradman wrote:
| See Ian McGilchrist's 2009 book _The Master and His Emissary_
| :
|
| > McGilchrist digests study after study, replacing the
| popular and superficial notion of the hemispheres as
| respectively logical and creative in nature with the idea
| that they pay attention in fundamentally different ways, the
| left being detail-oriented, the right being whole-oriented.
|
| [1] https://en.wikipedia.org/wiki/The_Master_and_His_Emissary
| judge2020 wrote:
| Without listing the actual misconceptions some people have,
| it's hard to say 'the left brain/right brain divide' is a
| misconception since I was already aware of this
| understanding that they just observe in different ways, not
| that "left brain is creative and right is logical". I grew
| up with the internet, though, so my understanding didn't
| solely originate from grade school science books that might
| be simplifying this phenomenon.
| nullserver wrote:
| I get minor strokes every couple of months.
|
| Each time I lose feeling in right side of body, and lose
| the ability to write. Not 100%, but close enough. Typing
| is fine however, if slow. Critical thinking goes to crap.
| Talking is fine. I can still draw, though my motivation
| goes to crap.
|
| Is weird what stays and what goes.
|
| Last time I looked writing is a left brain activity.
| Which controls right side.
| anaphor wrote:
| Usually the right hemisphere is linked with comprehending
| speech/writing, rather than producing it, so it's
| interesting that you lose the ability to write. Is your
| speech affected at all? It could be because writing
| involves a bunch of other more domain-general brain
| functions too I guess.
| ianhanschen wrote:
| I think he's talking about motor control - how the left
| hemisphere is responsible for controlling the right side
| of the body and vice versa.
| nullserver wrote:
| Correct. Right side body is numb, cold and weak. So I
| assume issue is left side of brain.
|
| I can read and speak well enough. Thinking is harder, so
| I tend to stay quiet.
| impartial-word wrote:
| My son has total agenesis of corpus callosum and he is 100%
| asymptomatic. We discovered accidentally in the last
| ultrasound the doctor did and confirmed with magnetic
| resonance.
|
| The brain is complex.
|
| Edit: https://en.wikipedia.org/wiki/Agenesis_of_the_corpus_ca
| llosu...
| tamatech wrote:
| Look into corpus callosum separation (split-brain) and some
| of the experiments that have been performed after this
| procedure. Fascinating displays of two separate
| consciousnesses. Sam Harris' Making Sense Podcast #234 had
| Iain McGilchrist to discuss this in some detail.
| ianhanschen wrote:
| That is what I am referring to :)
| steverb wrote:
| I would further add that those oversimplified concepts of how
| the brain works have hung around because they are useful for us
| as an abstraction to think about how our brain works.
|
| They may be bad abstractions at a lower level of detail, but
| for general purposes they seem to be useful enough.
| pessimizer wrote:
| What are they useful for, though? The usefulness of wrong
| models, and why they hang around so long, mainly seems to be
| to provide income to people selling solutions.
|
| Solutions offered based on bad simple metaphorical models
| have the benefit of being intuitive, so they stick around.
|
| Theory-theory is the Efficient Market Hypothesis applied to
| common sense.
| lukas099 wrote:
| They are useful as a standard way to talk about the brain.
| If I say I am 'right-brained' in casual conversation, most
| people in my culture know what I mean.
| anaphor wrote:
| Obviously you know this, but the brain does localize some
| functions to either hemisphere, just not in the way most people
| think it does. My vague memory from having taken a class in
| psycholinguistics is that people with aphasia who've had some
| part of their brain damaged are good evidence of this
| localization.
|
| https://en.wikipedia.org/wiki/Wernicke%27s_area
| https://en.wikipedia.org/wiki/Broca%27s_area
| phkahler wrote:
| Yeah, and the amygdala has specific functions. Not that it's
| the only piece needed for that, or that it's not good for
| anything else.
|
| The evidence for more advanced brains in higher mammals is
| also plainly there.
|
| The author seems to be over-stating all this stuff in order
| to reject it.
| anaphor wrote:
| And it's also the case that even though certain brain
| functions are linked with specific locations, the brain can
| still use plasticity to re-organize things and adapt to
| damage. And when you're doing any language related task,
| there are always going to be other more domain-general
| brain functions involved too, which aren't as localized.
| lycopodiopsida wrote:
| Having done a neuroscience degree myself, I would double on
| your conclusion -- I still have no clue how a brain works,
| apart of some simpler systems, like visual pattern recognition.
| I am out of the field for a single-digit number of years
| already, but in retrospective it is hilarious how all the
| literature in neuroscience is gently moving around the question
| of <<guys, bit how all of it works>>? People are happy to hack
| on single neurons or do some fishy fMRI studies instead. But of
| course, our tooling today is not adequate for this task.
| hn_asker wrote:
| Yet somehow Pharma can prescribe drugs that affect the
| brain's functions. How do they get away with that knowing so
| little about the brain?
| lycopodiopsida wrote:
| I am by no means an expert in pharmaceutical studies, but I
| suppose they can afford a huge number of dead ends in the
| initial phase of research due to the massive wealth and in
| the end, they have to test only for two variables:
| efficiency and side-effects. An explanation on how it
| actually works, is a very nice extra, but is not required.
| The problem for Pharma is that at some point you require
| tests on human subjects, which is very expensive and
| dangerous.
| caddemon wrote:
| A lot of original psych drugs were also discovered by
| accident, intending to address some other medical issue.
| For example MAOIs were found to have antidepressant
| effects during a trial to use them for tuberculosis.
| Development of SSRIs (e.g. Prozac) then came from trying
| to create a similar drug with less side effects.
|
| Also, the many dead ends thing is true in general for
| pharma, but at some point there are too many dead ends
| for it to be profitable even given their bankroll. This
| is happening a lot lately with neuro-related drug
| development. In the last 10 years I know Amgen, Pfizer,
| Novartis, Eli Lilly have all had shut downs/lay offs in
| their neuroscience research divisions.
| itronitron wrote:
| You might be interested in reading about Stuart Hammeroff
| who is an anesthesiologist and professor focused on studies
| of consciousness...
|
| https://en.wikipedia.org/wiki/Stuart_Hameroff
| vlunkr wrote:
| They give random drugs to rats until something happens.
| pvarangot wrote:
| And then to humans
| devindotcom wrote:
| Psychiatrists are doctors who prescribe substances that
| have been closely studied - but their effects may be easily
| and specifically understood, their mechanisms may not be.
|
| Lithium is a great example - very effective treatment for
| bipolar. No one really knows why. Prescribed for decades as
| they've tried to figure it out because tests showed it was
| effective and relatively safe, just no one knew exactly
| what it was doing in there.
|
| It's sort of how you can be a woodworker without knowing
| the cellular biology of trees, and without being an
| electrical or mechanical engineer who can build a table saw
| from scratch.
| adolph wrote:
| The discovery of it is pretty interesting.
|
| _Lithium-rich mineral springs have historically been
| touted for their healing properties. It was first used
| for mania in the late 1800s, with Denmark leading the
| way, but little was published about the medication for
| more than half a century._
|
| https://www.verywellmind.com/lithium-the-first-mood-
| stabiliz...
| hntrader wrote:
| This is a good argument as to why we should look closely
| at traditional medicines of various cultures. We (1)
| coevolved with this stuff and (2) have gone through
| generations of trial and error.
|
| I'm a believer in modern scientific medicine, but think
| we often have it backwards. Before reinventing the wheel
| we should exhaustively test what we used traditionally.
| Maybe the reason we don't do much of that is that it's
| not possible to patent, and so there's no financial
| incentive to do so?
| adolph wrote:
| There seems to be a good bit of different literature
| studying traditional cultural practices. Maybe it flies
| under the radar compared to flashy high-tech stuff. Below
| is a link to related articles about fermented beverages.
|
| https://pubmed.ncbi.nlm.nih.gov/?linkname=pubmed_pubmed&f
| rom...
| cratermoon wrote:
| > fishy fMRI studies
|
| Subtle, but I get it :D
| Afton wrote:
| > fish fMRI studies
|
| Link for those curious about this comment:
|
| (Neural Correlates of Interspecies Perspective Taking in the
| Post-Mortem Atlantic Salmon: An Argument For Proper Multiple
| Comparisons Correction)[https://teenspecies.github.io/pdfs/Ne
| uralCorrelates.pdf]
| mikepurvis wrote:
| Well, I expected fishy as in _dubious_ , not like literal
| fish.
| andyxor wrote:
| Now is the perfect time to build models of 'how all of it
| works', just like Kepler did with Tycho Brahe' astronomical
| observations.
|
| There is plenty, more than enough, data to work with, and
| many promising/proven models to build upon, need more good
| theorists in the field.
|
| Saying "but we don't know much" is just being lazy.
| devindotcom wrote:
| I did a minor in neuro and had a very similar experience.
| Fascinating and useful but it was always slightly alarming
| when the professor would answer a question with "I don't
| know.. no one knows. That is far beyond the limits of our
| capabilities to know." A reminder that scientists really do
| work at the edge of ignorance!
| OrbitRock wrote:
| That to me is really how we need to be emphasizing
| education in science for young people.
|
| We tend to give the impression that we've figured almost
| everything out, and so you're just learning the facts of it
| all.
|
| Really, we've carved out a little island in a sea of
| ignorance, and the foundations of the island are just our
| current best rough approximations that might collapse.
|
| An example from the field I'm in -- biology. It's quite
| likely that if you worked at it you can describe a new
| species in your backyard. You don't have to go to the
| Amazon rainforest, there's scientific unknowns all around
| you all the time.
| lukas099 wrote:
| The major questions of biology have already been solved,
| though. The rest is filling in the details.
| goatlover wrote:
| This doesn't seem to be true at least for the nervous and
| immune systems. Probably also the microbiome we host.
| There's lots of important stuff yet to be learned with
| those systems.
| nescioquid wrote:
| I read the parent's comment in terms of how we once
| viewed life being mysterious, talking about the "elan
| vital" before we understood DNA. This is often used as an
| analogy to our current struggle to understand
| consciousness.
| lotsofpulp wrote:
| What? This very thread is about an article talking about
| the lack of accuracy in our model of the brain's
| mechanisms.
| ramzyo wrote:
| > However the author appears to be arguing from a position that
| they (or someone) actually know how the brain works
|
| Interesting that you had this takeaway, I didn't get a sense of
| this at all. My takeaway was that the author presented modern
| findings (which constitute our present model for how the brain
| works, speaking nothing to a notion of some absolute
| correctness) to dispel older hypotheses that are disprovable
| based on the latest research. As presented, IMO, the author
| captures well that these modern findings are just a reference
| point against which to refute the stubborn tropes.
| teucris wrote:
| The central thesis is excellent, but this really caught my eye:
|
| > Depression is usually catalogued as a mental illness, but it's
| as much a metabolic illness as cardiovascular disease, which
| itself has significant mood-related symptoms. These two diseases
| occur together so often that some medical researchers believe
| that one may cause the other. That perspective is steeped in
| Cartesian dualism. Both depression and cardiovascular disease are
| known to involve problems with metabolism, so it's equally
| plausible that they share an underlying cause.
| carabiner wrote:
| I wish this to be true. I'm in excellent cardiovascular health
| - low BP, 60 bpm resting heart rate, extensive cardio/endurance
| activity 4-5 days per week. Utterly miserable every waking
| hour.
| lukas099 wrote:
| I am so sorry to hear that and I hope you are able to get any
| help that you need.
| pvarangot wrote:
| I struggle with depression for periods of time but have
| mostly always been fit. In my experience, even though it's
| contrary to most "broscience" out there, diet helps more with
| depression than working out.
|
| What working out does definitely improve is my sex drive and
| self-esteem, so it's important to know what's the triggers
| for your depression, as it may help anyway.
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