How technology inspired neuroscientists to reinvent the brain


It’s hard to talk about the human brain without talking about inadvertently computers. “I’m still processing,” you might say, or “Could we do a quick download of your findings? Then there’s the favorite line of over-stretched office workers: “I don’t have the bandwidth.”

There’s a reason computational metaphors are strewn across academic papers and brain lectures, according to Matthew Cobb, zoologist and author of The idea of ​​the brain, a deep dive into the history of neuroscience. As he scrutinized early brain research centuries back, he kept coming up against increasingly ancient mechanical metaphors.

“I realized that at different times, one of the ways people designed the brain was to draw a metaphor between what they think the brain does and the highest technology of their time,” explains he does. Different generations of researchers have established connections between the brain and automatons, electrical circuits and the telegraph.

These technological metaphors served not only as illustrations of existing conceptions of the brain. Instead, Cobb says that comparisons to inventions such as the telegraph wire – which could transmit information from a central node to distant points in the countryside – actually helped researchers reimagine the brain, thus stimulating their understanding of the structure and function of the brain.

“Once I realized that scientists were using these metaphors or analogies, it allowed me to understand for myself why there have been shifts and shifts in our understanding,” Cobb says.

The last episode of Inexplicable, Vox’s Unsolved Mysteries of Science podcast, traces the impact of new tools like fMRI that probe the brain’s many secrets. But tools aren’t enough, Cobb argues: Researchers also need concepts or frameworks to interpret the data they collect from their tools. And technologies that have little to do with brain research have often inspired and influenced studies of the mind.

The following is a transcript of our conversation, edited for clarity and length.

So what’s the timeline here? When did we first start doing this?

Well the first thing to realize is that even an interest in the brain [came] quite late. For most of human history, the brain has not been the center of attention when it comes to perception, emotion, mind, spirit – no matter how. you name it. It has been an organ in the body like the liver or the kidneys or the heart.

You mention in your book that phrases like “heartache” or “pulling the cords of the heart” go back to this idea that thought occurs in the heart. So when do researchers in Europe start saying, “Ah, maybe it’s the brain after all? “

Not in an instant. You don’t have to have the idea that someone has suddenly had an experiment and said, “Aha! Instead, there is this slow build-up of certainty. First, there is the anatomical demonstration that the “viscera” like the heart have other functions. The heart is a pump, which was shown at the beginning of the 17th century – therefore, it does not have the means to do the mysterious affairs associated with perception and thought, etc.

On the other hand, the brain, as anatomical studies have shown, has all of these neurons, and it is connected by neurons to all the sense organs and everything in between. So gradually, during the 17th century in particular, people became more and more convinced that it was the brain that thought. How he did it, they weren’t quite sure. Descartes, the French philosopher, looked at mechanical, water-powered, animatronic statues, and he thought, maybe we have some kind of hydraulic system inside of us.

We don’t, and it was quickly shown that there is no kind of hydraulic energy inside our neurons. But this is an example of people trying to use technology to explain and understand how the brain works.

[Researchers were later inspired by clockwork automata, like the one below.]

I think the telegraph is the example that has best helped me understand how having a technological metaphor has really helped researchers understand the brain. Can you tell me what happened there?

The telegraph was finally mastered in the mid-1830s and 1940s, and incredibly quickly it spread across entire continents. And almost immediately, scientists drew a parallel between these telegraph networks and the nervous system and the brain.

This metaphor of communication, threads, and most importantly, there is information in those threads – news, facts, and orders – going from the center to the periphery to make things happen. It has changed the way we think about the brain a lot.

How to think of the brain like a telegraph, to send signals electrically from one point to another, how has this helped the researchers?

They examined, for example, the structure of submarine cables that carried telegraph messages across the Atlantic, and they could see that there was a central copper core and that around it was insulation. . And then they looked at the neurons, the nerves, and they said, “Well, that’s exactly the same thing. There is this outer sheath that seems to isolate it. So even our understanding of the most basic units of the nervous system began to be completely merged with our understanding of technology.

When did they get to the point where they realized that maybe this telegraph metaphor had its limits, or was it not a perfect analogy for the brain?

Well, the key problem with the telegraph system is that it is fixed and the wiring is static. It doesn’t change. You send a message from the head office to your branch in a suburb, and that’s it. You cannot decide to redirect this message to the head office, branch or somewhere nearby.

What happened was that new technology came along and people started to think, “Well, actually the brain is a lot more like a telephone exchange. Because that was the next big development.

A switchboard operator in Kansas City, Missouri.
Jack Delano / Farm Security Administration (Library of Congress)

A telephone exchange, is it like switchboard operators who plug in and unplug cables?

A telephone exchange at the end of the 19th century consisted of a grid of slots with incoming wires. And if you wanted to phone someone, you would pick up your handset at home, and a light would come on in the local exchange. And one of the telephone operators, who would normally be female, would then plug a cable into your slot.

She would then say: “What number do you want? And then she would connect that wire to the number you wanted to talk to. The key point here is therefore that messages can change destination. The wiring is flexible, in that it changes depending on what you are doing, and that has coincided with an awareness of the structure of the nervous system. Some amazingly beautiful neuroanatomies, with new spots that people were developing, allowed them to see these structures under a microscope in particular.

These structures and their interconnections have changed over time, and they have grown, and our nervous systems are not fixed. And it looks a lot more like a telephone exchange than a telegraph system. You still get the idea of ​​messages going through the wires, but now that can change – it can change and it’s plastic.

At the end of the 19th century, the Spanish physician Santiago Ramón y Cajal mapped the neural networks in the brain, making very beautiful drawings. He struggled with the telegraph as a metaphor because his anatomical work showed too much plasticity and flexibility. Instead, he turned to plant metaphors.
Cajal Institute, Spanish National Research Council (CSIC)

And after the phone?

Well, the dominant metaphor is that the brain is something like a computer. It’s doing some sort of math. And this idea, which emerged in the 1940s and early 1950s, still dominates more than 70 years later.

There are distinct limits to this metaphor. There aren’t many scientists who would say, “Literally, the brain is like a computer with a central processing unit, with a graphics card. If I take my graphics unit out of my computer, it will have no image, whereas if I’m damaging a particular part of my brain, if I’m lucky there may be enough plasticity in other parts of my brain to recover some aspect of these functions. Brains are alive.

If we see the limits of this metaphor that we have been working with for 70 years, is it because the computer metaphor has somehow exceeded its usefulness? Is there a better metaphor?

Well, if I knew it, I would be very rich. I’m not sure just saying “Yeah, we need a new metaphor” is going to help us. When I was a student holograms were big business, but people gave it up. More recently, with the advent of cloud computing, people have started to say, “Well, maybe the brain looks a little more like a cloud computing system. But there haven’t really been any experiences that have emerged from using the metaphor.

Brains have evolved over perhaps 600 million years. Each animal line has a different type of brain that reacts and processes the world in different ways due to its evolutionary past. So maybe our brains don’t have a single explanation. It may be a mistake. Maybe we’ll have to settle for lots of little explanations.


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