WebZine
2017.02
What's New
New Record: Paralyzed Man Uses Brain Implant to Type Eight Words Per Minute
By Eliza Strickland
Posted 21 Feb 2017 | 18:00 GMT
“What did you enjoy the most about your trip to the Grand Canyon?” the Stanford researchers asked.
In response, a cursor floated across a computer screen displaying a keyboard and confidently picked out one letter at a time. The woman controlling the cursor didn’t have a mouse under her hand, though. She’s paralyzed due to amyotrophic lateral sclerosis (also called Lou Gehrig’s disease) and can’t move her hands. Instead, she steered the cursor using a chip implanted in her brain.
“I enjoyed the beauty,” she typed.
One-Step Optogenetics for Hacking the Nervous System
By Emily Waltz
Posted 20 Feb 2017 | 16:00 GMT
Engineers have taken one of biotech’s hottest tools—optogenetics—and made it better. The 12-year-old technique, which enables scientists to control brain cells with light, typically requires a multi-step process and several surgeries on animal models.
Polina Anikeeva at the Massachusetts Institute of Technology (MIT) and her colleagues came up with an engineering solution that combines those steps into one, and improves the function of the device. The group described their invention today in the journal Nature Neuroscience.
Optogenetics enables researchers to hack into the body’s electrical system with far more precision than traditional electrical stimulation. The technique involves genetically altering specific neurons so that they can be turned on or off with a simple flash of light
The woman was one of three participants in a study, published today in the journal eLife, that broke new ground in the use of brain-computer interfaces (BCIs) by people with paralysis. The woman who took the Grand Canyon trip demonstrated remarkable facility with a “free typing” task in which she answered questions however she chose. Another participant, a 64-year-old man paralyzed by a spinal cord injury, set a new record for speed in a “copy typing” task. Copying sentences like “The quick brown fox jumped over the lazy dog,” he typed at a relatively blistering rate of eight words per minute.
That’s four times as fast as the previous world’s best, says Stanford neurosurgeon Jaimie Henderson, a senior member of the research team. Further improvements to the user interface—including the kind of auto-complete software that’s standard on smartphones—should boost performance dramatically.
The tool is useful for figuring out the functions of neural circuits—fire up a select few brain cells and see how the body responds. A mouse might run faster or eat more or become aggressive, depending on which neurons were manipulated.
So far, optogenetics research has been limited to animal models. That’s partly because the tool is invasive and the process rather protracted. First the animal’s brain cells must be genetically altered. One way to do that is to incorporate a light-sensitizing gene into a viral vector—the non-infectious kind—and inject it into the brain using a small syringe.
The genetic modifications cause the neurons to produce proteins and other cellular elements that, when exposed to light, allow ions to enter. An influx of sodium ions will activate the neuron, causing it to fire, and starting a chain reaction among the neurons connected to it. An influx of chloride ions, on the other hand, will inhibit the neuron.