The Electric Commentary

Friday, December 30, 2005

Science is Fun!

New Scientist is no stranger to the ubiquitous year-end top ten list, and their list is a beaut'. Of the items on the list of important developments in science this year, this is my favorite:

The HAL 4 and HAL 5 prototypes, which will also be demonstrated at Expo 2005, don't just help a person to walk. They have an upper part to assist the arms, and will help a person lift up to 40 kilograms more than they can manage unaided. The new HALs will also eliminate the need for a backpack. Instead, the computer and wireless connection have been shrunk to fit in a pouch attached to the suit's belt. HAL 5 also has smaller motor housings, making the suit much less bulky around the hips and knees.

HAL 3 weighs 22 kilograms, but the help it gives the user is more than enough to compensate for this. "It's like riding on a robot, rather than wearing one," says Sankai. He adds that HAL 4 will weigh 17 kilograms, and he hopes HAL 5 may be lighter still.

Sankai has had many requests for the devices from people with brain and spinal injuries, so he is planning to extend the suit's applications to include medical rehabilitation. The first commercial suits are likely to cost between 1.5 and 2 million yen ($14,000 to $19,000).

Maybe next Christmas I'll ask for a super strong robotic exoskeleton. Cool.

And if you missed it earlier this year, they give you a chance to revisit the 13 things in science that, as Johnny Cochrane would say, do not make sense. The Placebo Effect is weird:

DON'T try this at home. Several times a day, for several days, you induce pain in someone. You control the pain with morphine until the final day of the experiment, when you replace the morphine with saline solution. Guess what? The saline takes the pain away.

This is the placebo effect: somehow, sometimes, a whole lot of nothing can be very powerful. Except it's not quite nothing. When Fabrizio Benedetti of the University of Turin in Italy carried out the above experiment, he added a final twist by adding naloxone, a drug that blocks the effects of morphine, to the saline. The shocking result? The pain-relieving power of saline solution disappeared.

So what is going on? Doctors have known about the placebo effect for decades, and the naloxone result seems to show that the placebo effect is somehow biochemical. But apart from that, we simply don't know.

Benedetti has since shown that a saline placebo can also reduce tremors and muscle stiffness in people with Parkinson's disease (Nature Neuroscience, vol 7, p 587). He and his team measured the activity of neurons in the patients' brains as they administered the saline. They found that individual neurons in the subthalamic nucleus (a common target for surgical attempts to relieve Parkinson's symptoms) began to fire less often when the saline was given, and with fewer "bursts" of firing - another feature associated with Parkinson's. The neuron activity decreased at the same time as the symptoms improved: the saline was definitely doing something.

We have a lot to learn about what is happening here, Benedetti says, but one thing is clear: the mind can affect the body's biochemistry. "The relationship between expectation and therapeutic outcome is a wonderful model to understand mind-body interaction," he says. Researchers now need to identify when and where placebo works. There may be diseases in which it has no effect. There may be a common mechanism in different illnesses. As yet, we just don't know.


  • Some guy actually got mildly famous in some medical circles for arguing that the FDA standard of "more effective than a placebo" was a bad standard because (as he argued) placebos were so effective.

    By Anonymous Scott H, at 11:24 AM  

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