Based on the scientific research so far, neuroscientists consider three things to be the human brain’s most important characteristics: complexity, changeability (plasticity), and infinite potential. As a brain philosopher and brain educator, I’m glad that my personal experience with my own and other brains led me to the same discovery about the brain.
The Brain Is Complex
The complexity of the connectivity between our brain cells is mind-boggling. The brain may be the most complex structure in the entire universe, not to mention the human body. Previously, I mentioned that our brains start out with 100 billion neurons. A single neuron creates 1,000 to 100,000 synapses, resulting in 125 trillion synapses in the cerebral cortex alone. That’s at least 1,000 times the number of stars in our galaxy! And each of these synapses is like a minicomputer, ready to contain and process information.
The way this information is processed makes the brain even more complex. A particularly fascinating form of processing is commonly called “pattern recognition.” Those studying this phenomenon ask how the brain, even when viewing an object for the first time, knows what kind of object it is. The brain has an uncanny ability to match information perceived by the senses with information stored in its memory, which helps us make sense of unfamiliar things.
For example, if we see the letter “A” in a fancy new font we’ve never seen before, we’ll still be able to recognize it as an “A” because it matches information we hold in our brain about the letter. We’re also able to read a handwritten letter “A,” even though everyone’s handwriting is unique. The human brain perceives the letter “A” as an “A” regardless of how it’s written.
Thanks to this pattern-recognition capability, we’re able to understand and use a variety of symbols — including language — and we can engage in the cognitive function of abstraction, which finds and universalizes the common elements of different objects. This allows us to interact well with each other, too, since we’re able to read and react to the meanings of facial expressions, despite their great diversity in different individuals.
Understanding this brain characteristic is central to the development of artificial intelligence. Thanks to the application of pattern recognition principles, we now use phones that can understand commands spoken by humans and convert handwritten notes into text for storing or sending by email.
Where and in what form, then, does information on such patterns exist in the human brain? The answer to this question hasn’t yet been precisely determined, but researchers are certain that it’s not a one-to-one relationship, like information stored on a hard drive. Rather, it’s believed to be a kind of multilevel structure that’s still not fully understood. Stated simply, specific information isn’t stored in a specific neuron or circuit. Rather, identical networks or neurons can participate simultaneously on many levels and carry different information, depending on the levels on which they’re operating. In short, our brain is extremely complex, and the amount of information it can handle is virtually infinite.
The Brain Is Always Changing
The brain likes change. Change is happening in your brain right now, in the very moment you’re reading this. If you feel fascination with the content of a book, if you’re moved or even inspired by some part of it, then the changes taking place in your brain will be even greater.
Just a few decades ago, scientists generally agreed that a person’s brain no longer changes after they reach a certain age. Even after the lifelong potential of the brain to change was recognized, it was commonly held that brain cells are continuously lost following birth and no new brain cells develop. It’s now understood, however, that synapses and neural circuits definitely change throughout life, and that new brain cells are also created regardless of age. Neuroscientists call this property of the brain “plasticity.”
There have been many cases of miraculous recovery from brain injury, thanks to the brain’s plasticity. In one case, despite the fact that doctors had completely removed one hemisphere of a patient’s brain, the other hemisphere fully adopted the missing hemisphere’s functions. The patient’s brain eventually functioned completely normally, as if it had both hemispheres. In another case, a patient showed cognitive abilities on a level that could be called “genius” even though he had only 10 percent of normal brain volume.
Conversely, there have been cases where a specific area of the brain has been removed or the neural network in a certain part of the brain has been cut, resulting in a totally different personality or a great loss of cognitive ability.
The changeability of the brain is, in fact, a great hope to us all. It means that painful memories of the past can be forgotten or healed with time, and we can always have new experiences and accept new information. Thanks to this brain property, we can examine ourselves, alter our habits and thinking, and even change our personalities.