Monday, July 15, 2019

What are some of the wrong assumptions about the brain?


There are so many incorrect assumptions that crop up here on Quora that I created a topic called Neuromyths and Neuroconfusions!
Here is a list of the most common misconceptions I come across on Quora and in popular culture generally:
I. We use only 10% of our brains

This is wildly false. We use 100% of our brains, since the neurons that are not firing are also “in use”. Having all cells fire at the same time would be like pressing the accelerator and the brake of a car at the same time! (As a neuroscientist on Quora, I find it quite depressing to see that this question seems to get asked multiple times every day!)

II. The left brain is “rational” or “logical” while the right brain is “emotional” or “creative”.

This particular misconception arose from neuroscientists, but we have been arguing that it is false for several decades. Sadly the media is relentless in spreading this incorrect factoid. (The most irritating aspect of it for me is the lazy assumption that creativity does not require logic, and vice versa.)


III. Dopamine is the happiness molecule

This is a more subtle issue, since even many neuroscientists say things like this. Dopamine is definitely involved in rewarding events. But that is not the whole story. Dopamine is also released after painful events, and as a result of certain types of stress. So it is deeply misleading to say that dopamine is devoted to one simple task. We are still trying to figure out what dopamine is doing. These days I think it makes more sense to think of dopamine as a “lubricant” for behaviour and learning. This lubrication is not necessarily pleasurable or good. In the case of drug- or stress-induced dopamine release, it can be quite bad. More broadly, dopamine hype is a symptom of a wider problem: the idea that the brain/mind is a “chemical soup”, rather than a complex and dynamic network.

IV. Emotions are opposed to rationality

This is another subtle one. There is no doubt that excessive emotionality can interfere with calm rational thinking, but the other extreme — no emotion — is equally bad. People with damage to their emotional systems cannot make normal decisions, despite seeming quite rational and sane. In the right proportion, emotions are a good thing.

V. Neuroscience can tell us how to be “smarter”

This is potentially controversial. We don’t really know what exactly intelligence or smartness is, especially from the perspective of brain science. We also know that “brain training” games are not particularly effective, other than making you better at the games themselves. General-purpose intelligence is not something you can target — it is too vague a goal. If you want to be good at something, you have to pick something specific and practice that. So far, neuroscience has not discovered any shortcuts, despite what you may have read on the internet. Sometimes the word “neuroplasticity” is bandied about like a magic spell. But the word “plasticity” just means “changeability”, and it is “always on” in the brain. You do not need to “turn on” neuroplasticity. Normal standards of health — exercise, sleep, diet etc. — are sufficient to maintain neuroplasticity. You brain will absorb whatever it is that you are doing. So focus on how you spend your time, since that is the main determinant of how and what you learn.

VI. Scientists can predict when major breakthroughs will take place

I often see questions asking for some kind of timetable for future discovery. Will mind-uploading happen by 2048? How on earth are we supposed to know? It strikes me that the people who make predictions of this sort are trying to sell something or inflate the value of some stock (including their own, as a prognosticator). Science is about studying the unknown, and therefore we have no idea when the unknown will cease to be unknown. We don’t know how much we don’t know. There are unknown unknowns. And typically, when we do make major discoveries, we find that even more mysteries arise. So a five-year plan for future discovery is an absurd thing to expect.

Reference: Yohan John


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