Updated: 5/16/2006; 3:05:49 PM.

Current events
Post-9-11 events and analyses


daily link  Tuesday, December 07, 2004


Cap Harnesses Human Thought to Move PC Cursor: Study published in the Proceedings of the NAS:  "Scientists have developed a non-invasive brain-computer interface that enables a person to move a cursor across a computer screen just by thinking about it. .. Before the new finding, many researchers previously assumed that only invasive brain-computer interfaces, in which electrodes are surgically implanted into the brain, could control complex movements. ..

Of the four people who participated in the study, two had severe physical disabilities. The subjects wore the electrode caps, which analyzed electroencephalographic (EEG) activity (brain waves) recorded from their scalp. The electrodes, small metal disks about a quarter of an inch (three-fifths of a centimeter) wide, were placed over the sensory motor part of the brain.

At first, participants learned to use their thoughts to direct a cursor on a computer screen by imagining specific actions, from running to shooting baskets. As they became more comfortable with the technology, the subjects began to rely less on such imagery to direct the cursor. Eventually, the participants couldn't tell what they were thinking about to move the cursor; they simply moved it. ..

Each session lasted 24 minutes. It took participants two to three sessions to begin to acquire control of the cursor movement. After ten sessions, participants were able to hit the target on a computer screen about 80 percent of the time.

The two study participants with spinal cord injuries performed better than the uninjured participants, possibly reflecting greater motivation or injury-associated brain changes. ..

"The computer automatically adapts to the person using the system," Wolpaw said. "It is an interaction between two adaptive controllers—the system and the person using it." Wolpaw predicts future improvements of the non-invasive brain-computer interface will focus on three-dimensional movement. In the future, users may be able to operate a robotic arm that could pick things up, or they may be able to control a neural prosthesis in which electrodes implanted in a paralyzed limb may be stimulated to get the muscles to move."

  12:25:25 PM  permalink  

Even the Economist has it on their cover:  "How long can [the dollar] remain the world's most important reserve currency? ..

the privilege of being able to print the world's reserve currency, a privilege which is now at risk, allows America to borrow cheaply, and thus to spend much more than it earns, on far better terms than are available to others. Imagine you could write cheques that were accepted as payment but never cashed. That is what it amounts to. If you had been granted that ability, you might take care to hang on to it. America is taking no such care, and may come to regret it. ..

America's challenge is not just to reduce its current-account deficit to a level which foreigners are happy to finance by buying more dollar assets, but also to persuade existing foreign creditors to hang on to their vast stock of dollar assets, estimated at almost $11 trillion. A fall in the dollar sufficient to close the current-account deficit might destroy its safe-haven status. If the dollar falls by another 30%, as some predict, it would amount to the biggest default in history: not a conventional default on debt service, but default by stealth, wiping trillions off the value of foreigners' dollar assets.

The dollar's loss of reserve-currency status would lead America's creditors to start cashing those cheques—and what an awful lot of cheques there are to cash. As that process gathered pace, the dollar could tumble further and further. American bond yields (long-term interest rates) would soar, quite likely causing a deep recession. Americans who favour a weak dollar should be careful what they wish for. Cutting the budget deficit looks cheap at the price."  Background online.

  8:35:09 AM  permalink  

 
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Copyright 2006 © Ken Novak.
Last update: 5/16/2006; 3:05:49 PM.