Thursday, August 27, 2009

Machines That Read Your Mind

The Dawning Age of Mind-Reading Machines
By Hilmar Schmundt
Imagine controlling machines, typing text or juggling balls using nothing but the power of thought. What sounds like far-fetched science fiction is gradually becoming possible, providing hope for disabled patients -- and new gimmicks for the computer gaming industry.
DIZ SENTENS IS WRUTEN WID TAUGHTS. No keyboard, no hands, no blinking even. I think, therefore I write.
My original plan was to write this article with nothing but the power of thought, but the technology of transforming ideas into characters is still crude and prone to error. The first word alone took a few minutes, and even after that the result was still "diz" instead of "this."
Still, that little sentence is like a little miracle. The old dream of mind-reading is slowly becoming reality -- though this time around it is the product of machines rather than the minds of fiction writers.
"The advances are tremendous," says Christoph Guger, the developer of a brain-reading system. "In the past, you would have had to train for days. Today, entering text takes only a few minutes."
Guger is an engineer and a businessman. But with his hair falling past his jacket's collar, he looks the part of a start-up entrepreneur. Still, he is certainly not new to the business. His company, Guger Technologies, which is based in the Austrian city of Graz, has been a supplier to countless brain-research laboratories for years. In addition to scalpels and medications, though, Guger also sells thought-transport technology.
Guger recently presented his latest thought-reading system at a workshop entitled "Brain-Computer Interfaces" held at Berlin's Charité, one of Europe's largest university hospitals. The new electronic interfaces between brain and computer are referred to as BCI.
Hardware and Wetware
The goal of BCI is to enable the user to use thoughts -- instead of a keyboard, mouse or touch screen -- to control a computer's actions. But what sounds like telepathy is, in fact, quite banal. First the user puts on a device that looks like a bathing cap. Then an electrically conductive gel is squeezed through small holes in the cap onto the scalp. Finally, eight electrodes are plugged into the cap, and a colorful array of dreadlock-resembling cables are attached to the electrodes. The cables are then connected to the computer through a signal amplifying interface. So much for the hardware.
Then the "wetware" -- the term IT researchers sometimes use to refer to the brain -- takes over. An alphabet flickers across a screen in front of the subject, and the letters light up one at a time. The user waits until the letter he or she wants to use appears. When it lights up, the brain has an involuntary reaction that produces a small "electric potential," a tiny increase in voltage of about 15 microvolts, which is 100,000 times weaker than the voltage generated by a flashlight battery.
The principle is based on the tried-and-tested EEG, or electroencephalogram. The brain's small gray cells fire off electrical signals, which can be measured on the surface of the scalp. Guger's special method is called P300, a reference to the sudden fluctuation in voltage he is looking for, which appears in the visual cortex of the brain 300 milliseconds after each expected letter flashes on the screen.
This method is very rudimentary in the sense that it doesn't really read a thought but, rather, merely the average activity of millions of neurons. Likewise, those neurons may not be reacting only to letters, but also to someone else's sneeze or to tightness in the subject's left shoe. Guger's current task is to filter all of these interfering signals out of the chaotic flow of thoughts in the brain.
Brain Caps for Pinball
As challenging as this task might be, there was still a lot of excitement at the Berlin workshop. The project involves a rapidly growing group of researchers hoping to capture thoughts with what can best be described as an electronic camera. "Ten years ago, there were perhaps a dozen research groups in this field," says Klaus-Robert Müller, the director of the Machine Learning/Intelligent Data Analysis Group at the Technical University of Berlin. "Now there are more than 200."
Müller has also developed a BCI that works in a similar way to Guger's mental typewriter. His system isn't based on tediously poking around in a jumble of letters but, rather, on lightning-fast reactions. To develop the system, Müller has his subjects use their brain caps to play pinball.
When they think "right," the lever on the right side pops up. As if moved by the hand of a ghost, it flings the ball back into the game without anyone having touched the controls.
Müller is working closely with John-Dylan Haynes, one of the stars of the elite thought-reading community. Haynes attracted attention last year when he reported that, using a magnetic resonance imaging (MRI) machine, he had correctly guessed the decisions of his subjects before they were able to act in more than half of the cases. A full seven seconds before they moved a finger, Haynes could see that they were planning to press a specific button.
After Müller's presentation, Niels Birbaumer stood up to speak at the Berlin conference. Birbaumer is the director of the Institute of Medical Psychology and Behavioral Neurobiology at the University of Tübingen in southwestern Germany and is considered a pioneer in the field. For years, he has been trying to teach people with physical handicaps to control their wheelchairs or prosthetic limbs using only the power of thought. "Our successes are still modest," he says, "but I'm already totally crazy with hope." He expects that within two years he will be able to use his system with locked-in patients -- that is, paralyzed individuals who are fully aware of their surroundings but can move nothing other than their eyes -- for the first time within two years.
Communication with these types of patients is something of a Holy Grail in the profession because it promises to make it possible to help locked-in people like the lead character in the 2007 film "The Diving Bell and the Butterfly." In the film, an almost totally paralyzed patient dictates his memories to his therapist using the only means of communication he has left: blinking.
Eavesdropping on Dreams
Completely locked-in patients, on the other hand, can't even blink. All they can still control is their neurons.
The prospect of getting a glimpse of those thoughts is by no means hopeless. Birbaumer has already demonstrated that the brain waves of locked-in patients respond to various pieces of music, familiar faces and grammatical errors.
The BCI experts now believe that their technology is on the verge of a major breakthrough. Their successes are indeed astonishing, but they still have a long way to go before realizing their ambitions. Last fall, Japanese researchers reported in the journal Neuron that -- with the help of a technology known as functional magnetic resonance tomography -- they had observed the brain processing certain images. This promptly led them to speculate that one day it might even be possible to eavesdrop on the "illusions and dreams" of the brain.
In an atmosphere in which everything seems possible, though, there is a great temptation to hope that the power of thought can somehow make the pitfalls of technology magically disappear. But we still haven't reach a point yet where we can control things with thoughts alone. For example, for many years now, the American firm Emotiv has advertised a system that allows paralyzed people to control their wheelchairs. But neither emotions nor thoughts are involved. Instead, Emotiv's technology is based primarily on signals produced by facial muscles. It has everything to do with smiling and blinking -- and nothing to do with controlling with your thoughts.
But what happens if the day comes when we actually are able to drive cars -- or even fly fighter jets -- using our thoughts alone? The US Department of Defense finds this vision so promising that it has already invested $4 million (€2.8 million) to develop a certain kind of telepathy. The goal of the project -- dubbed "Silent Talk" -- is to enable soldiers to communicate with each other "on the battlefield without the use of vocalized speech through analyis of neural signals."
Opinions vary on how much of this research is science and how much is science fiction. A report by the MITRE Corporation, a consulting firm headquartered in Virginia, derisively describes brain control as a crude technology. According to the report, the problem is "in part due to the early stage of development of the associated technologies, and in part due to limited understanding of the central nervous system." The report soberly concludes that "the possibility for using such brain control in a military scenario is not readily apparent."
Even the prophets of the new era cannot deny that many systems are highly prone to error. In most cases, the detection rate is around 70 percent. In addition to the cable cap, the conductive gel and a computer, users also need a great deal of patience. Another problem is that about 30 percent of subjects have proven to be "EEG-illiterate." In other words, their brains remain impervious to the machines.
All too often, exorbitant promises are associated with this visionary technology. For example, in the game "Mindball," two players wearing EEG headbands compete by becoming as relaxed as possible. The player who is better able to relax his brain -- and thereby occasion uniform vibrations -- can drive a ball the farthest onto his opponent's side of the game table.
According to the companies that sell the game, it can provide significant benefits to players. They cite a study "conducted by London's prestigious Imperial College demonstrated that EEG feedback can improve academic performance and creativity."
Electrifying Audiences
The distinctions between science, art and slapstick are often vague, especially when people do things like artist Adi Hoesle, who produces "EEG sculptures" or sells colorful swirls on a canvas while claiming that they are images of his thoughts. One of his works is titled: "I'm so surprised by the red in my head." Meanwhile, an orchestra in which some of the instruments are brain-controlled is performing in small theaters around Europe. Its musicians wear gimmicky, brightly colored EEG caps on stage.
Such theatrical effects are part of a long tradition, a sort of colorful flipside of science. For example, when so-called "natural philosophers" were studying electricity around 1750, they developed parlor games, such as producing sparks when a couple kissed. They also hoped to use therapeutic bursts of electricity to help lame people walk again. Their audiences were -- literally -- electrified.
Even a company like Mattel, known mainly for its Barbie Doll products, has now discovered the allure of brain control. The new system Mattel is introducing at computer trade shows is called "Mindflex." According to the company's fact sheet: "A true mental marathon, Mindflex exercises the brain in an entirely new way as players learn to continuously control their brain activity."
So, you ask, how does it work? To train the brain, the user puts on a headband with sensors at the temples and a cable connected to something that looks like a mini miniature golf course. Then the user tries to master the first task: balancing a small ball above an air current, causing it to levitate and making it pass through a plastic ring.
A cluster of curious onlookers has formed at the trade show. The players are doing their best not to get nervous, collect their thoughts and concentrate on the ball. Sure enough, the more they are able to descend into mental nothingness, the higher the ball hovers in the air.
Mattel refuses to divulge how the device works. Experts assume that the headband -- like the sensors used in Mindball -- measures alpha waves that pulse through the cerebral cortex at about 10 times a second when a person relaxes.
In any event, playing these thought-controlled games produces an indescribable sensation. It's as if you were using a new muscle that you had only heard about but never experienced -- the organ underneath the top of the skull. Astonished audiences must have felt a similar sensation in the 18th century, when a kiss produced a spark.
It took another 200 years before it was discovered that what was once a cheap party trick could have many other uses and that the science on which it is based keeps the Internet, the stock markets, the global economy -- and thoughts -- running today.

No comments: