3/8/2010

Artificial Intelligence is the intelligence of machines and the branch of computer science that aims to create it. In my book Dead Head a human brain was able to produce speech by use of a brain/computer interface – a device for translating thoughts into mechanical actions. One reviewer considered this to be “science fiction.” Well it isn’t.

For years neuroscientists have struggled on decoding brain electrical activity recorded from the scalp down to individual neurons. They’ve made progress, too. One multidisciplinary research team from a consortium of universities has developed a brain/computer interface they call Braingate. http://www.braingate2.org/aboutUs.asp This device is a small grid of needle-like electrodes that penetrate the brain surface (the pia) to record from multiple neurons simultaneously. Implanting this device requires surgery to open the scalp, skull and Dura. The cable from the electrode grid is then tunneled to a separate area where it can be connected to a computer. The electrodes are implanted into the brain region that controls movement of the opposite hand of subjects who have lost the ability to use their arms from a variety of neurological diseases such as stroke, muscular dystrophy, or Lou Gehrig’s disease. After the wound heals the electrodes are sampled to determine which ones are recording and which are not.

The subjects are then shown a computer screen similar to an old game of Pong where the object is to move the cursor into a target. Because the electrodes are within the arm/hand region of cortex, subjects “think” of moving the object with their hands and can learn to manipulate the cursor so with surprising accuracy. As subjects gain efficiency in controlling the cursor, they can spell out commands (for those who have lost their ability to talk) or move robotic devices that can help them accomplish tasks.

The downside of Braingate2 is the requirement of an implanted recording device. To work around this other research has sought to decoding brain activity recorded at a distance from the brain, like the scalp. But with increased recording distance comes weaker signals and interference from other electrical activity (such as muscle and even heart contractions) (see 2/19/2010 blog) including surround brain. As a result, scalp recording are more complex and difficult to control by subjects, so progress is slower than with Braingate.

The good news is that as complicated and cumbersome as these experiments are today, they indicate tremendous strides in technology that may one day help the neurologically damaged patient.