Nothing about the brain is foreign to David Eagleman, neuroscientist, technologist, entrepreneur and one of the most interesting science writers of our time.
Born in New Mexico 52 years ago, he researches brain plasticity, synesthesia, time perception and what he calls
neurolaw
, at the intersection between knowledge of the brain and its legal implications.
His book
From Him Incognito.
The Secret Lives of the Brain
, from 2011, was translated into 28 languages, including Spanish in Anagrama, and now returns in the same publishing house with another ambitious work,
A Living Network
, which revolves around a fundamental idea of current neuroscience: that the brain is constantly changing to adapt to experience and learning.
His science is not only first-class, but also first-hand, but his brilliant, crystalline writing—a perfect reflection of his mind—turns one of the most complex issues in current research into a triumphant ride. for the reader.
We spoke with him by videoconference in the first interview he has given to a Spanish media in the last decade.
Could a newborn's brain learn to live in a five-dimensional world?
“We still don't know how much there is genetics and how much experience in our brain,” she responds from California by videoconference.
“If we raised a baby in a five-dimensional world, which would surely be a very unethical experiment, we might find that the child can figure out how to function there.
The general theme of brain plasticity is that everything is more surprising than we thought, in the sense that the brain is a design capable of learning anything that the environment presents to it.
More information
Robert J. Sternberg, psychologist: “Your intellectual abilities change, intelligence is learned”
Eagleman pulls out a voluminous bowl of salad from somewhere, puts what will fit on his fork into his mouth, and continues his argument: “Your example of the five-dimensional world is highly hypothetical, but what we do know, of course, is that babies born anywhere in the world, whether in a hyper-religious culture or in a secular country, in an economy based on agriculture or in another technologically overdeveloped one, like here in Silicon Valley, adjust their brains to any of those environments.
My children adapt to using a tablet or a mobile phone just as well as other children, in other places, adapt to agricultural tools.
So yes, we know that our brain is actually very flexible.”
The distinction between genetics and experience, or between nature and nurture, is not as clear-cut as it may seem.
It is common to think that genes build the brain and then the environment takes over by modifying the strength of the connections between neurons (synapses) or establishing new contacts.
But forming new connections and modulating old ones requires reactivating the same genes that built the brain in the first place.
I put this question to you.
“The way we think about brain biology is that experience involves changes at all levels, so yes, you're right, genes have to be involved in brain plasticity.
It is true that the usual thing is to investigate plasticity at the level of neuronal cells and the synapses that they form, strengthen or weaken, but the main reason is that this is easier to measure.
Experience modifies the brain at all levels, and the distinction between synapses and genes is not real, but rather an arbitrary boundary drawn by us, the human observers,” he responds.
A long century of neurology has established that the cortex (or cerebral cortex), the outer layer that gives the brain its wrinkled appearance, is divided into hundreds of specialized areas: seeing, hearing, speaking, projecting, managing emotions and everything else.
However, anatomists have not found major differences between the circuit architecture of some areas and others, and no specific genes are known for each area.
What does this mean?
One of the lessons of Eagleman's new book is that the brain is the same thing everywhere.
“The cortex uses the same trick, the same circuit architecture, in any area.
The only reason we see distinctions—this area is dedicated to visual information, this one to hearing—is because each receives different input cables,” says the neuroscientist.
For example, information from the eyes enters through the optic nerve to the back of the brain, and that is why that area becomes what we call the visual cortex, but if you go blind that same cortex becomes auditory, tactile or other things.
So there's nothing fundamental about this compartmentalization of the brain, Eagleman explains: it's just a question of which input cables are plugged into one area or another, that is, what type of information it receives.
Mysterious evolution
The evolution of the brain is currently as mysterious as its functioning.
The six million years that separate us from chimpanzees are barely a blink of an eye on evolutionary scales, and some scientists believe that the key lies in the mere increase in the size of the cortex, which has tripled compared to chimpanzees and australopithecines.
Eagleman is one of them.
“Our cortex is much larger than that of any of our animal cousins, and this is a big part of the
magical change
from them.
There are other parallel changes, such as a large larynx that allows us to communicate quickly through spoken language, or an opposable thumb that is a great help as well, but the main difference is the size of our cortex.
The scientist continues: “This implies that there is much more territory between the
input
and the
output
(the input and output information), so that, when one receives sensory information and has to emit a response, in most animals Those two areas are very close to each other, but in our case they are further apart.
The result is that, when you see something, you can make other types of decisions.
If you put food in front of me, I can take into consideration that I'm on a diet, or that I don't want to eat that right now because I'm doing intermittent fasting, or whatever, before I jump on the food.
Eagleman teaches neuroscience at Stanford University, California, but his work as a researcher and teacher falls far short of his deep and restless mind.
He is the chief executive of Neosensory, a company he helped found that is dedicated to developing technology so that the blind and deaf can regain part of their faculties by recruiting areas of the brain that are normally dedicated to other things to replace the lost sense. .
He is also the chief scientist of
BrainCheck
, a digital platform to help doctors diagnose cognitive problems.
In addition to writing high-quality informative books, he writes and presents the television series
The
Brain with David Eagleman and the
podcast
The Interior Cosmos with David Eagleman
.
If there is a backbone to all that frenetic activity, it is harnessing the brain's knowledge to help medicine in innovative and creative ways.
“Consciousness is the great unsolved mystery of neuroscience.
There are those who believe that they are just algorithms”
The next question was inevitable.
And yes, Eagleman has used ChatGPT.
He says that the fascinating part about these large language models (
LLM
, the type of systems ChatGPT belongs to) is that right now we are more in a time of discovery than invention.
Most of the things we've invented in the past—a washing machine or a coffee maker—we know exactly how they work, because we designed them, he says.
But these LLMs are full of surprises and do things that no one expected, not even their programmers.
"This is amazing.
I think what they do really, really well is find connections that we hadn't thought about.
LLM models have read everything that has been published in the world, have an all-encompassing memory and can find unexpected links if you ask them the right question.”
Eagleman believes that ChatGPT's ability is extremely valuable to science.
“Every month 30,000 new papers (peer-reviewed scientific articles) come out and I can't read all of that, but the LLM can.
I recently published a paper in which I propose that there are two-level scientific discoveries.
Level one is about putting together things I just didn't know, and ChatGPT can be helpful there.
But that's different from level two discoveries, which require imagining a model that doesn't exist.”
“Albert Einstein,” Eagleman continues, “wondered how he would see light if he were riding on a photon, and that thought experiment led him to the special theory of relativity.
What he did was not put together things that were already in the scientific literature, but rather imagine a new model and develop a simulation with it.
And I'm not so sure that artificial intelligence can do that at the moment.
I think that's why we scientists still have work.”
Scientist David Eagleman in his laboratory at Baylor College of Medicine, in Houston, Texas, in 2009Joe Baraban
But Eagleman is also a writer.
And he also believes that he will keep the job in that other side of him, because, while ChatGPT can write “surprisingly cool” answers on various questions, as a writer he is not particularly creative.
“You and I can structure paragraphs or call back to a previous passage, and ChatGPT is far from that, at least for now.
So no, I am not worried as a writer either,” he states.
But I tell you that the AI can copy you:
—You are a master at finding analogies, metaphors and illustrative examples.
Maybe the model can analyze his books and imitate him in all that, I ask him.
“Writing is hard, you know,” he responds politely.
I'd be really amazed if ChatGPT could write a good book in 10 years, but I'm not convinced it can.
Writing a good book involves putting together new ideas, new models, thinking about them and asking: what kind of story can I tell to start this chapter and introduce that concept?
How to link it with what will come next and then and then?
While I'm writing a book I'm thinking about all those levels at once, and what the reader's experience can be like, and how to make a reference to what came before, how the rhythm is sounding, it's like you're composing a symphony.
Since ChatGPT and the rest of LLM only
think
about what word to type next, they can't think about all the levels at once.
Eagleman explains that what's so hard to imagine about ChatGPT is that “he's read every book ever, every blog and website, and he remembers all of that.
What this illustrates is that, at a fundamental level, we are also something like a statistical machine, and that if you copy those statistics and know which word goes next to another in every text that humanity has produced, the result is much better. “than we had imagined.”
Mind/machine
One of Eagleman's areas of research is mind/machine interfaces, small panels of electrodes that are implanted in the brain to help people who are blind or deaf.
How do these electrodes connect with the correct neurons?
“We know the area we are interested in controlling.
For example, if you are trying to move a robotic arm, you puncture the area of the cortex that normally controls the arm, and you also do not record a neuron, but an entire collection.
In a normal situation, if someone puts a weight on your wrist, it will not take long for you to modulate your brain commands to move your arm in that new situation and not knock over the coffee cup, and the same thing happens with patients.
Our brain is used to changes in the body, it's like saying: this is the goal I want to achieve, so how do I get there with what I have?
That is why mind/machine interfaces do not need to contact the exact neurons.
The person knows that he wants to move a robotic arm, and he figures out how to do it.”
The cortex is made of repetitive units called columns, tiny in surface but with millions of neurons in a stereotyped organization of circuits.
They repeat over and over throughout the entire cortex, Eagleman says, “like the ribs of a snake.”
Everyone is interested in knowing what that column does, that kind of basic unit of the brain.
There is a lot of data, but we still don't understand what it is about.
According to him, “what the structure of the cortex does is convert data into representations that are useful for acting in the world, and this requires abstracting details.”
Will machines achieve a form of consciousness?
“Everyone has an opinion about it, but we don't really know.
Consciousness is the central unsolved mystery of neuroscience.
One idea is the computational hypothesis, where everything is algorithms, and if we replicate those algorithms in silicon we will have consciousness.
"Other schools think there is something particular about the biology of the brain that we haven't discovered yet."
It's amazing what a salad can do.
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