Livewired, by David Eagleman, likens the neurons in our brains to countries competing for territory. Every time you learn or feel or move or hear, your brain physically changes. 3 lessons:
- Our neocortex is pluripotent. Blind people recognize tactile motion in their occipital lobes (where you ‘see’). Put on a blindfold, you start to do the same in 45 minutes.
- A life with more variety and mental stimulation maintains a greater degree of plasticity. A predictable life, or one focused on expertise, solidifies your brain more quickly.
- Slower layers of our memory provide scaffolding on which faster memories form. Faster memories, if salient and repeated, change the underlying structures.
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This blog post is part of a series I am making called Reading For The Aspirational Self. Don’t think of this as book summaries – I’m not doing that. Instead, I’m drawing out specific lessons that I find particularly interesting. And which I think could act, together, to help people who share my aspirations. If you, too, want to be present, family-centric, intrinsically motivated and polymathic, I can help.
- The most distilled version of what I’m offering is a free mailing list designed for learning, “Think On Thursday” – each e-mail will include a lesson designed around the content. Click here for some information on that.
- The series is also on YouTube in the form of 7-12 minute videos. Here’s the channel link – the video and transcript are below.
- I’m tweeting excerpts from the videos, as well as some of the story of this project, how we’re doing it, and where it is going, on Twitter. @DaveCBeck
If you want to know more about Livewired you can check out Eagleman’s website here.
This week’s video
Livewired by Daniel Eagleman shows us how the neurons in our brains are probably best thought of as individuals or networks competing for territory. Our brains are hugely flexible. And every time you learn or you feel, or you move or your hair, your brain is physically changing. It’s live wired.
I’ll talk through how our brains take in information. Secondly, how our capacity for live wiring declines as we age, especially if we focus our lives on one or two things. And thirdly, I’ll talk a little bit about what neuroscience knows and doesn’t know about memory.
(section – what is livewiring?)
For Eagleman, the term that you might know for neurological change plasticity just doesn’t cut it. It’s not sufficient because our brains don’t just melt, form a new shape, and be stuck in that shape the way that plastic does. Change is constant. And it can be remarkably fast. And so if you put on a blindfold within about three quarters of an hour, you, you might notice that some of your other senses are heightened, whether that’s touch or taste or smell or you’re hearing, you’ll be able to do things with your other senses that you wouldn’t normally be able to do within just three quarters of an hour. And if you study somebody’s brain activity, while they put a blindfold on and do other things, you’ll see that their visual occipital cortex, the area that’s normally just dealing with your eyes right back here, start showing activity that you wouldn’t really expect.
Eagleman asks what if the localization that neuroscience has gone through is something of a dead end, but actually the areas of our brain don’t have mostly anything specifically interesting about it. And actually you can consider each area as a kind of processing device. And it’s the data that you feed it that makes the area. So he refers to a chlorine potent neocortex. The neocortex, the area near the outside of the brain all looks the same because it is the same. And it’s actually the data that you feed into the brain that make the area do things differently.
So the best example of this is what happens in the occipital lobes for blind people, especially those blind from birth, or they’ve also people blinded relatively early in their lives show much of this. And even if you’re blinded later, some of this can happen.
When blind people read braille and they’re using their sense of touch to, to recognize the characters, the areas of their brain that would normally recognize visual characters that, that kind of section of the occipital lobe is active. When blind people feel a tactile sense of touch, of motion, sense of touch. The same region of the brain is activated as for you or me, would be activated for visual motion.
The region of their brain. That’s normally active. For vision that is, has been colonized by their other senses. So Eagleman often talks in terms of seeing the different regions of your brain as fighting for territory. And in the case of people who’ve been blind since birth, their ocipital lobe is basically colonized. It’s all active in a different way for different senses. And even if they become blind later on, most of it will be colonized.
(section – our flexibility declines with age and routine)
Your brain’s ability to what he calls live wire – to change its wiring, declines as you age and declines as you fall into well-worn routines. The brain’s tendency to react autonomously and without much kind of activity or conscious choices is shown in lots of different ways.
The motion after effect is a really interesting one. If you stare at a waterfall for long enough, as Aristotle found out, and then look away, it will look like the rest of the world is moving up because your body, your brain has adapted to the idea that all of the stuff that surrounds the center of your vision is moving.
Everything is moving down all the time and the brain has adapted to that. So then when you look at something that isn’t moving in the real physical world, it looks like it’s moving up.
What you do and how you live your life, particularly things that you focus your attention and your time on can often be read in your brain. So you can tell from a scan of somebody’s brain, whether they play piano or a string instrument by the development of their motor cortex. So a little kind of puckering appears on the motor cortex if you practice a habit like play piano or a string instrument for an awful lot of time, the traditional, you know 10,000 hours to develop a skill at something that’s fairly narrow, like playing one of those instruments. And you develop that pucking with a string instrument. It only happens on one side of your brain with a piano it happens on both sides because you’re using both hands in just as complex a way.
You see this with particularly habit forming mental activities too. So the example is normally given is London, taxi drivers, who, who memorized in the past – I presume they don’t still do this, maybe they do -memorize the route map of London, so they could always get around and find their way around. And that extension of their spatial memory was recognizable on neurological scans.
Your brain physically changes when you do new things, but it’s not just about practicing them. It’s also about understanding the salience of them and wanting them to be part of you rather than just something that you’re doing, a habit that you’re doing, because you’re forced to.
And what Eagleman talks about is how a salience, so a kind of conscious knowledge of why this thing is important to you and a desire to do it. And, and a focus on it increases the plasticity of your brain in the region that is active at that moment. So that part of your brain is more prone to rewiring itself because you want it to. Basically.
It’s, it’s not quite that simple. It’s actually, because you want the thing and you’re feeling those emotions led by desire and your brain activates a certain set of neurochemicals. But basically if you want something to become part of you and you practice it, you have to put in the time too, you can rewire your brain quite drastically.
Rewards also increase the plasticity. So that dopamine hit comes alongside some of the neurochemicals that probably increase plasticity or that kind of happen at the same time as something else that we don’t understand that increases plasticity. I love how Eagleman is very qualified in terms of what he knows and what he doesn’t know.
And as you’ll have got from these videos. If you’ve watched any of my prior videos, that’s the sign of somebody who really understands their field. They see what they don’t know as well as what they do know. And he’s refreshingly honest about this.
There are several things that lead to less plastic brains, so less ability to rewire. One of them it’s just age. So when your children under six or seven, they’re in what neurologists will call the sensitive period, their brain can adapt phenomenally quickly, to incredibly difficult things like losing sight, almost completely, almost as though it had been from birth. There were a couple of things that have to happen within the first year or two.
For other things, your brain is able to rewire later. But in that period of up to six or seven, your brain is at its most plastic, basically. And as time goes on, it becomes less plastic and it becomes more difficult to create new ways of looking at the world.
There’s another thing that leads to less plasticity and that’s expertise. So if you are focused for the majority of your life on one thing or one area, your brain is probably less plastic than somebody who has lived a more varied life. It’s more difficult for somebody who has been an expert in their fields, you see this in sportsman as well. It’s more difficult for people who have that level of expertise and focus and practice in one area to learn new tricks. It’s not just about age. It’s also about expertise in a specific place, rather than a more, varied, general sense of expertise.
Variety, and a constant input of new data, Eagleman hypothesizes, that the more data that’s novel that you feed your brain, the more plastic your brain generally is. So the more you can expose yourself to new things and not just go through old routines and the more plastic your brain will be. And the more you will be able to adapt to different circumstances as time goes on and to rewire yourself consciously, if you choose to.
So, I talk about memory, finally. I love again, Eagleman honesty here. It’s an incredibly complex area, and it’s likely that most of the paths that neuroscience is going down now to try and explain memory largely about synaptic strengthening, the way that net networks rewire themselves, neurons, that fire together, wire together.
It’s likely that they’re all dead ends and they won’t explain anything. it’s an incredibly complex area. There are a few things we do know about memories that are fairly fixed. So older memories are more stable. It’s something called Ribots Law. And those older memories are central to ourselves too, they’re really important to us.
There are several types of memory, so there were several different types of memory that look different in the brain, as well as feeling different. Memories aren’t overwritten. You don’t have a fixed memory capacity that you can fill up, or at least not one that anybody’s found yet.
They’re probably moved, if they’re salient or if you repeat them a few times. So the hippocampus stores, your short-term memories, we think, and then if, if those memories are rehearsed a few times, it moves into the cortex. And if they’ve rehearsed a few times in the cortex, they become more accessible and they are more likely to be part of your longterm memories.
It also helps if they kind of link different things together. So the more connections that you have there, and the more likely those memories are to become long-term. But like I say, synaptic strengthening is probably a consequence of something we don’t understand. So that explanation is probably wrong.
There are two areas that are not explicable by the synaptic strengthening of memory explanations at all. So one of them is neurogenesis. And so when you’re experiencing new information, your brain forms and keeps about twice as many neurons as it normally would. Your brain is constantly creating new neurons, but it doubles when you’re forming new information.
And also epigenetics. So how our genes are expressed in our brain changes with our world experience. So even with the same DNA, the way that they’re expressed in your brain and the rest of your body is different depending on what you do. And that’s a type of memory too. It’s a very long term one.
So Eagleman thinks we should talk about timescales from fast biochemical changes, somewhere in the middle is the synaptic strengthening thing, and gene expression is at the slower end. This is one of the reasons that learning something again is faster and because you’ve already got the foundations and experience and the kind of basis that those shorter term memories can be built up.
They don’t have to do anything to change the rest of your brain. So when you try and speak a new language for them, first time, it’s really hard. The second time it becomes easier. And then if, even if you leave it for a few years, the third time, it becomes easier. Again. That that’s kind of a well-known thing.
Or if you haven’t rode a bike in a few years, but you used to a lot, when you were a child, you can get on a bike now and you can probably ride it reasonably well because of that school of experience, that scaffold of experience.
They’re very individual too.