How our brains are NOT like computers!
On the neuroplasticity of the human brain
“To see something stationary, our brains have to scribble our eyes very subtly over its surface. Experiments have even proved that if you artificially stabilize an image on the retina with a combination of special contact lenses and microelectronics, the image will vanish.” — Sam Kean. The Tale of the Dueling Neurosurgeons: The History of the Human Brain as Revealed by True Stories of Trauma, Madness, and Recovery.
I’ve been reading a lot of books recently on neuroscience, mental disorders, and how the brain works. I’m fascinated not just by the complexity of the human brain and its impressive reasoning capabilities but also man’s attempts to decipher how this powerful supercomputer actually functions, how it deals with trauma, and how it heals and reprograms itself with no external assistance or manipulation.
There are many studies out there that have shown the amazing plasticity of the human brain: stories of people who lost large chunks of their brains due to birth defects or as a result of accidents or a lobotomy yet somehow managed to live an almost normal life. The results are sometimes hard to believe but are meticulously researched and documented by scientists. The brain, in these cases, automatically rewires and reprograms itself and recovers even from catastrophic failures.
One of the most famous examples is that of Phineas Gage, a 19th century railroad worker, who was impaled by a massive iron rod which entered through his lower jaw and exited from the top of his head, removing with it a large chunk of his brain.
Amazingly, he was able to sit and even speak within a few minutes of the accident. He ended up losing an eye but managed to live a relatively uneventful life, albeit with some personality changes, for another twelve years. Imagine if you took a hammer to your computer and still expected it to work afterwards!
“I gotta tell you… The life of the mind. There’s no roadmap for that territory… and exploring it can be painful.” — John Turturro. Barton Fink.
Neuroscientists have been carefully studying the brain and have identified specific regions that are responsible for many functions. I’m sure you’ve all seen those colored pictures of the brain: This part over here controls your hearing, this part controls language, this part controls logical thinking, etc.
They’ve even drilled holes in people’s heads and poked and prodded those regions to show that they can manipulate specific functions: If I apply an electric current to this spot, you’ll taste liver and onions.
The results are, as expected, consistent in all people with a normal brain. The only problem is the last two words in that sentence: “normal brain”. Change the brain in any way, say through a birth defect or by performing a lobotomy, and you find that it automatically repurposes other regions to perform the particular function that used to be handled by the missing part.
That, to me, is the most amazing fact about the human brain — not how it functions under normal conditions but rather how it fixes and reprograms itself in millions of unique abnormal situations that it couldn’t have possibly encountered in the past.
The scientific literature is replete with incredible case studies and many books have been written on the topic. One of the most startling examples, in my opinion, is the recent publication of a scientific paper: Perfectly normal 24 year old Chinese woman complains of dizziness, X-Ray reveals her entire cerebellum (home to half the neurons in her brain and responsible for much of our motor activities as well as parts of language) is missing — apparently a genetic defect.
Yet, for all practical purposes, she is a healthy adult woman and no one really noticed any problems over the first two and a half decades of her life. Her mother remembers that she started walking and talking a couple of years later than normal — which means her brain was busy reprogramming itself in those two years so other regions could pick up the responsibilities usually handled by the cerebellum. The end result? Almost no externally visible degradation in performance; the only complaints that brought her to the hospital were some slight dizziness and occasional vomiting. Unbelievable, yet true.
Another example is hemispherectomy, a rare medical procedure in which an entire half of the brain is removed to reduce epileptic seizures. Studies “have found no significant long-term effects on memory, personality, or humor, and minimal changes in cognitive function overall.” Wow! Just wow!
It’s as if your laptop were to wake up one morning and say to itself: “Dammit, I see both the hardware and the software for the disk controller are not working properly. Let me just rewrite the network driver to take over that function and repurpose this chunk of silicon from the graphics controller over there to perform storage operations instead!” Meanwhile, the rest of the system, including graphics and networking, continue to work with little or no degradation in functionality and performance.
Note that this is very different from a loosely coupled cluster of computers (multiple brains) making forward progress in the case of a single node failure or even network partitioning. It’s the equivalent of a single computer continuing to work properly even after you attack the motherboard with a blunt instrument.
As you read about the human brain and its neuroplasticity, you realize that any comparisons to the “artificial intelligence” of computers and new advances in “deep learning” algorithms is laughable. We can’t even keep our simplistic computers working with a dozen specialists (engineers, support people, operations team, etc) on-call round the clock; we have to throw away the hardware and the software every few years and start over again.
Computers becoming smarter than us soon? Don’t make me laugh. Computers may be better (read: faster) than us in some respects but that is a superficial advantage at best. We have been reprogramming our brains for millions of years. Evolutionarily speaking, the computing industry is not even at the mammalian stage of development yet. In terms of plasticity, it would be more apt to compare today’s most powerful supercomputers to Darwin’s favorite barnacles than to a human brain.
If I could talk to my computer, I’d remind it of Woody’s immortal words to Buzz Lightyear in Toy Story: “YOU ARE A TOY! … You are a child’s play thing!”
The next time we get all proud of ourselves for the quality of our software, its “robust” error handling capabilities, or its (snicker) self-healing algorithms, we should remember the story of the software that runs us — non-stop for a hundred years, 99.9% defect free, with no need for reboots, no need for an “OS upgrade” or even “hardware” replacement.
And, oh yeah, by the way, it heals itself and reprograms itself around massive partial system failures, too.