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Myths about the brain

nautil.us

21–30 of 80 posts

Re: Myths about the brain

#21
> 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…

Re: Myths about the brain

#22
post #3

> [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 functio…

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.

Re: Myths about the brain

#23
post #4

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 exam…

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

Re: Myths about the brain

#24
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...

Re: Myths about the brain

#25
post #3

> [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 functio…

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.

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?

Re: Myths about the brain

#26

Earlier quoted context omitted.

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.

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?

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.

Re: Myths about the brain

#27
"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.

Re: Myths about the brain

#28

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 yo…

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.

Re: Myths about the brain

#29
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.

Re: Myths about the brain

#30

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.

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.
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