Dec. 7, 2004 — An electrode-covered hat can translate brain waves into computer commands, a non-invasive thought decoder that could someday let the disabled communicate by using their brains alone, according to a new study.

The hat may someday also be used to operate word processing programs or control movement of a robotic prosthesis.

The study is published in the current Proceedings of the National Academy of Sciences.

Jonathan Wolpaw, lead author of the study and chief of the Laboratory of Nervous System Disorders at the Wadsworth Center within the New York State Department of Health and the State University of New York, described the mind-reading hat to Discovery News.

"It looks sort of like a light-weight elastic version of an old-fashioned rubber swimming cap, with small metal disks that are connected by a ribbon cable to EEG amplifiers and the computer," Wolpaw said.

Wolpaw and colleague Dennis McFarland explained that brain activity can be detected from the scalp, from the cortical surface, or from within the brain itself. Some devices are implanted into the brain, but Wolpaw and McFarland's new cap is noninvasive and poses minimal, if any, risk to the wearer.

The problem with such caps in the past is that, like a bad radio, they would pick up all sorts of brain waves, to the point where the desired ones were lost or reduced to a quiet buzz amongst the din.

The new cap system, which scientists refer to as a brain-computer interface (BCI), has better tuning. It also has an enhanced decoder that not only conveys the user's intent to the computer, but also focuses on thought patterns determined to be successful in operating the computer. As a result, the device becomes easier for the wearer to use over time.

Wolpaw and McFarland tested the system on two disabled and two non-disabled adults. For the tests, a square would appear from various angles on a computer screen. A cursor would then appear on the screen. The user's goal was to move the cursor to the square target by thought alone.

The researchers kept check on muscle movements to ensure that only mind control, and not muscles, was moving the cursor.

All of the test subjects were able to hit the targets using the BCI, but the wheelchair-bound test subjects excelled over the non-disabled individuals.

"Based on many scientists' work, including work in our lab, showing that the nervous system has tremendous ability to adapt to new needs, it is possible that areas of sensorimotor cortex deprived of their normal function might conceivably acquire a new function, such as EEG (electroencephalographic)-based cursor control, more readily," Wolpaw explained.

William Heetderks, director of the neural prosthesis program at the National Institutes of Health in Washington, DC, told Discovery News that "the results reported in the PNAS paper are very encouraging."

Heetderks believes that once such devices are made available, "they will profoundly improve lives of some individuals whose thoughts and desires are otherwise locked within their bodies."

Dawn Taylor, assistant professor in the Department of Biomedical Engineering at Case Western Reserve University and a Research Associate at the Cleveland VA Medical Center, believes that both invasive and noninvasive BCI's will be beneficial to patients.

She said that her colleagues at the Cleveland Functional Electrical Stimulation Center are restoring arm and hand movement to paralyzed individuals through implanted stimulators that activate muscles. She is supportive of Wolpaw's work as well.

"Non-invasive BCI's have the potential to greatly improve the lives of the 'locked in' or completely paralyzed individuals by providing them with an efficient means to use a computer," Taylor told Discovery News. "With the right customized software, these most severely disabled individuals will be able to communicate by typing, control assistive robots, and control devices, such as their light or television."

Non-disabled individuals, who might be interested in giving up their keyboards, should not look for BCI's in the marketplace anytime soon.

"In the past, there have been a few failed attempts to commercialize non-invasive brain recording devices for playing video games, or creating 'mental music or art,'" Taylor said. "However, the non-invasive BCI's are still not as effective for playing video games as the standard hand controllers, so it is unlikely that these devices will catch on with the general public."