Do you ever wonder how the brain works and how we are able to think? The short answer is that we do not really know. The longer answer is that we know a lot about the workings of nerve cells and some simple brain circuits. But, the real brain function that we are all familiar with from everyday life “emerges” from the brain cells in a way that seems magical – much in the way that a melody emerges from specific combination of individual notes, and how the rich sound of music emerges from the combination of instrumental and vocal components. The outcome is more than its parts.
Good music is not random – quite the opposite. In fact, the word “orchestrate” denotes a precise order. As defined by the Merriam-Webster dictionary, it is “to arrange or combine to achieve a desired effect.” Yet, to someone who is just discovering the music and does not know the composer’s complete design, the resulting song cannot be produced based on knowledge of the individual notes alone.
Take the Eagles’ 1977 hit, Hotel California, for example. It is one of the most recognizable songs for its story line, its musical sound, and the way it makes you feel. Hotel California is ranked by Rolling Stone magazine in the top 50 songs of all time and was named by the Rock and Roll Hall of Fame as one of the songs that ‘Shaped Rock and Roll.’ The song has a captivating instrumental that just makes me tap my foot and sing along (sometimes with an air guitar accompaniment). But, that is only if the song is played according to its original design – with the correct notes, tempo, instruments, and really good musicians. The four different guitars must play their parts in the right way, and, of course, the drummer keeps the precise beat while emphasizing the right notes. Only then does the whole Hotel California song emerge in the right way, and only then do you get that good feeling when hearing it. To test this out, ask your neighbor’s son – the one practicing the trumpet every evening – to play Hotel California. You get the picture.
So, how is the brain like Hotel California?
Hotel California, like all good music, is complex. The complete song emerges from the precise coordinated activity of all its components. The brain is also complex. Indeed, it has so many aspects of complexity that scientists do not yet have the tools to study and analyze it properly. One consequence of this complexity is that the brain is not simply a clock-like machine, where its future states can be predicted from its current setting. That means that the brain’s function may seem magical, or perhaps random. But, just reflect on your own seemingly hard-wired thought patterns to realize that your brain is highly ordered and reliable. Neuroscientists just do not understand the brain to the point where they can predict what comes next. Indeed, the brain may be so wonderous that science may never fully understand it. So, how does it work? How can we behave so predictably?
First, I will explain a little about “complexity.”
We generally like to think that the world works in a strictly cause-and-effect manner, where you can predict what will come next with great certainty. People are very good at this type of logic. If we know the rule and know the current state, then we can predict the future state. The more unpredictable the situation, the more mysterious or magical it seems to us. If good music were simply a mechanical result of knowing which notes to play, then computer-generated music, or even a monkey with an organ-grinder, would be good enough for us. Musicologists tell us that it is precisely the unpredictability of the music that makes it interesting and enjoyable for us.
In science, this type of system is called “complex”, not because it is harder to figure out, but rather because our usual type of thinking is inadequate to understand the system sufficiently. For hundreds of years, since the late 1600’s, when Isaac Newton accomplished the unthinkable by capturing the essence of the known rules of physics in simplified mathematical equations, scientists have been obsessed with finding the simplest way of describing nature. This “reductionist” approach is very useful when trying to discover many aspects of nature, since it simplifies the rules to the point where they can be understood by us, or at least to the point where a computer simulation is useful. But, as scientists have learned, reductionism is inadequate for very complex systems, such as the weather, biology, natural ecosystems, and the brain.
The type of complexity that is most fascinating is called “emergence.” In the brain, emergence is responsible for all higher-order functions, starting from the way your brain knows to identify the image of a house as a house, all the way to your perception of reality and your ability to transcend yourself to empathize with others or to obtain a spiritual feeling of awe.
Going back to Hotel California, your brain hears the song in a rather strange way.
- First, the sound waves that are the physical carriers of the sound enter your outer ear and cause your eardrum to vibrate.
- The vibrations are transmitted to your inner ear, where your cochlea converts the mechanical waves to electrical signals by exciting a precise sequence of nerve cells, each one designed to fire when the vibration of a specific frequency is sensed.
- These auditory nerve cells convey the information by relaying the signals via a cascade of nerve cells in the brain stem and thalamus, finally reaching the auditory cortex, the outer layer of the brain dedicated to sound processing.
- The cells that fire in your auditory cortex as Hotel California is played send the information to other areas of cortex that are responsible for decoding the sounds and for mixing them back together as the perception of music.
- Having identified the sounds as music, other areas of the brain, such as those responsible for memory and for emotion, are pinged so they could contribute the information that the song is familiar, that it is called Hotel California, that this version is played by the Eagles, and that it brings you back to your college days with the warm memory of joking with your friends. The signals from nerves in the brain converge to mix all of the right things – what, why, when, and how does it feel. That brain process is called ‘binding’, and scientists still do not understand how it happens. The resulting perception and feeling emerges from the components in an automatic and reliable manner – in what can only be understood as a natural wonder.
There is much more to it, but this is enough to paint the picture. Consider how complex it is go from a series of sounds to the emotion of ‘ahh’ when remembering your college buddies. That result cannot be predicted by any computer program – it only emerges by an awesome chain of events that happen in the human brain.
This piece was adapted from my book Embracing the Unknown: A Fresh Look at Nature and Science, I talk a lot about complexity in nature, and how that fills us with a sense of awe and humility. There are many things we do not know about nature, but this type of complexity is what creates harmony and beauty. Emergence is a major reason why the more we discover, the more we understand how much we really do not know. Stay tuned for more …
Dr. Ely Simon is an adult neurologist working in Modiin, Israel. www.modiinneurology.com