miriam english (miriam_e) wrote,
miriam english

how the brain works

I just watched a wonderful talk by Nancy Kanwisher titled "A neural portrait of the mind". (My internet connection is really slow and I can no longer use the TED Talks website since its recent changes so I've given the direct download link to the lowest resolution, 512x288, version there.)

Recently, in the course of a conversation with an old friend I've known for many years, she said something that surprised and dismayed me. She said that what separates good thoughts and bad thoughts is that they have different frequencies (perhaps making an analogy to a radio in being able to tune in different frequencies). I attempted to correct this misunderstanding by describing how the brain is laid out, and that what distinguishes various thoughts and feelings from each other is actually connection -- the wiring map of the brain. In terms of the way the nerves in the brain respond, the sensation of the taste of a strawberry is exactly the same as the blueness of the sky, the pain of a bee sting, the sound of a birdsong, the luxuriantly moist air of a rainforest, the sense of space looking out from a high cliff, the pleasure engendered by a baby's bubbling laughter, the tingling protective pleasure I derive from patting my doggie friend Nata. What makes all these things different is where in the brain they happen. It is architecture, the way these messages connect to each other via the wiring that is important.

A number of times in the past I've heard people say, somewhat mystically, that the frequency of the thoughts is what makes them unique -- their vibration -- and that this explains telepathy. Of course, if pressed on this topic they generally have no real understanding of what is meant by "frequency" or the other mystical term often used, "vibration".

The original meaning of those words is very easy to understand. Frequency is how often something happens in a certain amount of time. For instance the frequency range of the human ear is roughly 10 Hertz to 20,000 Hertz. That is, you can hear sounds that are the result of air molecules being pushed back and forth as slowly as 10 times a second, which is a very low buzzing sound, to 20,000 times every second, making a very high pitched ringing. Frequency can describe much slower things too -- the frequency of my visits to town is roughly once every couple of months.

But when people speak with mystical intent of "frequencies" in the brain they seem to have a vague magical notion. I think it's fostered by a lack of understanding of what electromagnetic waves are, and how radios "tune in" to particular frequencies. They see it as a magical kind of thing, even though they probably know there is a logical explanation for it. Their magical lack of understanding is what allows them to believe in telepathy. They think that these "frequencies" can be broadcast.

I could explain that electrons are like those little paper windmills we all made as kids and would run with, delighting in how they rotate as we move them through the air. Electrons do something similar. As you move one along, its magnetic field rotates around it. Just like the little paper windmill held at arm's length and swished back and forth, it will rotate one way when moved in one direction then rotate the opposite way when moved back. If you move electrons back and forth in a wire alternately one direction then the other (alternating current, abbreviated to AC) then the field around it also rotates first one direction then the other. These changes try to happen in the electron's field all at once everywhere, but change can only propagate outward at the speed of light (about 299,792 kilometers per second), which although it is very fast is not instant, so you can imagine these reversals in the fields rippling outward as waves at the speed of light. But just as electrons affect the magnetic fields around them, it works the other way too, and a little like rotating propellers on airplanes can move the planes along, changing magnetic fields can move electrons. So when these electrons' magnetic (electromagnetic) fields change, rotating back and forth, they push electrons to move in a similar way to the ones that generated the changing field in the first place. If the electrons are in a conductor then they move easily, producing a weak alternating current. If we connect together some specially designed conductors (for example, a capacitor which resists low frequencies and a coil which resists high frequencies) so that they resonate with a particular frequency the way a guitar string resonates when plucked, then we can select one frequency of electromagnetic waves out of many being transmitted. This is, in a very simplified way, is how a radio tunes in a radio transmission. I could try to explain this, but I fear most people's eyes will glaze over and they'll stop listening after the first sentence... after all, this is science, right? One thing we all learned at school is that science is boring and hard to understand. But science isn't boring, and it is actually thrillingly easy!

Anyway, if people understood this I think it would go a long way to dispelling mystical notions such as telepathic waves that might be transmitted and received. However I am always depressed by the number of people who believe in gods and homeopathy and spirits, so I have little hope that many will even attempt to really understand the reality of the world we live in, preferring instead, one of magical notions.

It just amazes me that we live in an era of scientific advances that far outstrip anything that has gone before, but that most people have little more understanding of the modern world's wonders than someone from the dawn of civilisation thousands of years ago. So sad. I don't see this as anybody's fault, in particular, nor do I look down on the people who lack this knowledge. But it does worry me. Greatly.

(Crossposted from http://miriam-e.dreamwidth.org/325378.html at my Dreamwidth account. Number of comments there so far: comment count unavailable)
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