Tuesday, April 4, 2017

Probing (and prodding) the Brain

I got really excited recently when I learned about John Grisham's new book. And no I'm not a Grisham fan. But his new book means a lot to me because it's about something called "focused ultrasound," an extension of an idea I had many many years ago. I was never able to convince anyone it was viable. And I didn't have the resources to pursue it, but I always hoped someone would eventually figure it out -- and someone actually did. Finally. Grisham decided it was important enough to write a book about, and his book is free -- because he wants the news to be as widely disseminated as possible. It's a huge medical breakthrough, and I'm really proud of myself, because I had that basic concept in mind so long ago.

His book is called "The Tumor" and it's about this "focused ultrasound" method he's so enthusiastic about. What is "focused ultrasound"? You should know because some day it could save your life. Here's a link to the article in the Guardian. And here's the link to the book itself. It's free! 

My original idea was based on the notion of a "standing wave." What is a standing wave? Well, for example it's possible to create a standing wave in an auditorium so that the sounds can be heard in only one spot and no other. That wave is just standing there in that one place and all its energy is focused on that one spot. This is a known acoustic phenomenon. 

My idea was to apply this to the exploration of the brain using highly focused standing waves of extremely high frequency (ultrasound). By controlling the interference patterns among different pitches it would be possible to move the standing wave through various parts of the brain without doing any damage. But the volume would be just high enough to stimulate certain brain tissue very selectively and then observe the effect. For example you might be able to stimulate a particular memory, or induce a particular perception. By such a method one could map any brain in detail without the need for invasive surgery, such as electrodes, which are now used.

When I described this method to people with a medical or technical background they felt sure it would not work because our skulls are too thick to permit the sound waves to pass with any degree of control. They were wrong. If the ultrasound pitches are high enough, they will penetrate the skull no problem. So basically this is what "focused ultrasound" does, as far as I can tell. It can be used not only to explore the brain but also as a surgical tool, to destroy tumors -- in the brain but also anywhere else in the body, without the need for invasive surgery. 

When  I looked into "focused ultrasound" in more detail I learned that it's not quite what I'd predicted. They've found a way to create a kind of acoustic lens that actually focuses the sounds. (A detailed description of the history behind this method and how it works can be found in this Wikipedia article.) In fact standing waves can be considered a problem with this technology as they can appear where they are not wanted. However, this patent, describing an Ultrasound Standing Wave Application, seems quite close to what I originally had in mind.

Some background:

Back in the 60's I became very interested in the ability of audio vibrations to stimulate both physical and mental experiences. I did some experiments along such lines in 1968, while at the electronic music studio at the U. of Illinois, and produced a composition with extremely low pitches (that may or may not have carried subsonic sounds along with them) inspired by that idea. I did somewhat similar experiments with extremely high pitches as well. In 1977, I received a grant from the Media Center at SUNY Buffalo, to explore the possibilities of both ultrasonic and subsonic sounds and consulted with a local audio electronics guru (I think his name was Bode), to see if we could come up with designs for musical instruments that could play such sounds. The idea was the produce a piece of "music" that was inaudible, but nevertheless would be able to program the "listener's" mood in meaningful ways.

We were never able to produce such instruments, mainly because of the expense involved, but I've always been curious to know whether or not ultra- or sub- sonic sounds could have an effect on mood, or even thoughts. Sometime during this period, I got the idea that one might be able to stimulate specific brain cells, or contiguous groups of cells, by creating microscopic standing waves based on the interference of ultrasound pitches. Here's how I described it in an email sent a few years ago to a friend, when discussing the film, the Matrix:
You're probably the only one who knows enough about me to actually believe this, but the Matrix concept is very similar to an idea I had many years ago that scared a lot of my friends. My idea was to turn the brain into a synthesizer, using ultrasonic standing waves that could pinpoint specific cells in the brain and activate them. You'd just have to put on a pair of headphones and press the button and you'd have a completely synthesized virtual experience that would take over your whole "reality." My main interest was to produce totally abstract experiences involving floating among all sorts of colored lights and sounds. But I also thought you could also synthesize some sort of travel experience, where you could go anywhere in the world you liked in an instant and wander around the streets. I realized I'd need to design some sort of safety device in case things got too heavy. My first thoughts centered on things like parking meters, so, if you decided you needed to "bail out" of the virtual experience and get back to where you "really" were, you could turn the knob on a parking meter and the synthesizer would be turned off and you'd be back. When I saw how they used those telephones in the Matrix, that really was a kind of deja vu until I remembered my old "great idea." I realized that using such a device to synthesize "artistic" experiences was probably too scary for most people to accept, but since it had obvious implications for brain research and also therapeutic possibilities, it occurred to me that I might be able to get a foundation interested in helping me develop it. 
Since I knew nothing about how to pursue brain research, I needed a collaborator with a medical background, but everyone I discussed this with discouraged me, because no one thought such sounds could penetrate the skull. It's really gratifying to learn that someone actually figured out a way to do this and I'm really pleased to see how far they've taken it.


  1. Doc- as someone who's had a craniotomy to remove a non-cancerous colloid cyst, this is fascinating. I asked about something like this before they cut my skull open (I didn't call it "focused ultrasound," because I wasn't quite sure what I meant anyway). They do use an endoscopic method in some instances, but the little bugger can grow back, if it's not removed in its entirety. Focused ultrasound could be such a fantastic tool for something like this!
    Thanks for the book link. I'm certainly going to take a gander.

    1. Hi Candace. Yes, brain surgery can be a daunting experience. I'm assuming (hoping) you got through it OK. I do think focused ultrasound could represent a revolutionary breakthrough, as Grisham has envisioned, as it could, ideally, be totally noninvasive. It would also represent a huge boost to brain research. I hope they're getting the funding they need and look forward to learning more about their progress over time.