Myths about the brain

> 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.

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.

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.

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.

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.