25 October 1999
The connected brain
or
Das Wohltemperierte Klavier

From brainwaves controlling a cursor on a computer screen to inside-the-skull activity controlling outside activity, and vice-versa, the potential is being developed for enhancing freedom of mind as well as for enslaving it.

For some time, it had been possible for patients suffering from amyotrophic lateral sclerosis, a neurodegenerative disease, to compose messages and do other task by controlling the electrical potential of their brain waves. Electrodes attached to the skull near the motor cortex pick up the signals. The patients had to learn to make their cortical potentials more negative or positive to move a cursor up and down a computer screen. Here are some details from a report by the BBC Online Network of 25 March this year: 

"First the patient has to learn consciously to control a particular kind of brain activity which is called slow cortical potential, which everybody has," says Professor Niels Birbaumer of the University of Tübingen in Germany.

"It comprises slow changes in the excitation level of the brain. Patients learning to control this see their own brain activity on a computer screen in the form of a trace that moves up and down - so they can observe it continuously. 

"Then the computer or a therapist asks the patient to control the shape of the trace and to use it to move a cursor on the screen." [full story]

A next step is the control of movement from activity within the brain instead of encyphalographically, from the outside surface of the skull.  And the honor of making that step goes to rats. It is Dr John Chapin, of the MCP Hahnemann University School of Medicine in Philadelphia, who has shown this can be done.

First part of the experiment was to train rats using time-tested stimulus-response techniques. From a report by the BBS Online Network on 21 June of this year:

Scientists trained rats to obtain water from a robotic arm by pressing a small lever. Each rat had electrodes implanted in its brain to record the activity of certain cells. As the rats performed this task, the scientists analysed the patterns of activity in the regions of the brain that control movement and identified specific brain cell activity associated with the rat's paw movements. 

Then a direct link was made by connecting the robot arm directly to the rat's brain. The brain now controlled the robot arm directly through the electrodes and the computer.

The rats appeared to have little difficulty in controlling the robot arm. Initially, they continued to press the lever, even though this was no longer necessary to cause the robot arm movements. But eventually many rats learned that they could obtain water through brain activity alone and stopped pressing the lever. 

The medical benefit envisaged from this line experimentation is direct control of artificial limbs. [full story]

Next in line for scientific honors are cats. Condensed from a report by BBC News Online Science Editor Dr David Whitehouse on 8 October: 

Garrett Stanley, Yang Dang and Fei Li, from the Department of Molecular and Cell Biology, University of California, Berkeley, have wired a computer to a cat's brain and created videos of what the animal was seeing.  They attached electrodes to 177 cells in the so-called thalamus region of the cat's brain and monitored their activity. 

The thalamus is connected directly to the cat's eyes via the optic nerve.  Each of its cells is programmed to respond to certain features in the cat's field of view. Some cells "fire" when they record an edge in the cat's vision, others when they see lines at certain angles, etc. This way the cat's brain acquires the information it needs to reconstruct an image. 

The scientists recorded the patterns of firing from the cells in a computer.  They then used a technique they describe as a "linear decoding technique" to reconstruct an image. 

To their amazement they say they saw natural scenes with recognisable objects such as people's faces. They had literally seen the world through cat's eyes. 

Other scientists have hailed this as an important step in our understanding of how signals are represented and processed in the brain. Some day, scientists may be able to build devices that interface directly with the brain, providing access to extra data storage or processing power or the ability to control devices just by thinking about them. Stanley has already predicted machines with brain interfaces. [full story]

Thus far the BBC reports. We may conclude that Garrett Stanley is not the first person to make such a prediction. More than two decades ago, Carl Sagan wondered about that in his book The dragons of Eden.   He asked whether it will be possible some day to add:

"... a variety of cognitive and intellectual prosthetic devices to the brain -- a kind of eyeglasses for the mind. This would be in the spirit of the past accretionary evolution of the brain and is probably far more feasible than attempting to restructure the existing brain. Perhaps one day we will have surgically implanted in our brains small, replaceable computer modules or radio terminals which will provide us with a rapid and fluent knowledge of Basque, Urdu, Amharic, Ainu, Albasian, Nu, Hopi, !Kung, or delphinese; or numerical values of the incomplete gamma function and the Tchebysheff polynomials; or the natural history of animal spoor; or all legal precedence for the ownership of floating islands; or radio telepathy connecting several human beings, at least temporarily, in a form of symbiotic association previously unknown to our species."

It appears that science has now made great strides toward this outcome.  And, as a corollary, strides toward another outcome as well: the direct control of a human brain from the outside. Imagine aspects of such techniques patented by corporations with huge commercial and political powers. Then human brains may become well-tuned instruments in corporate hands. 

Shudder one may, but how much better to sharpen our ability to timely assess possible untoward events by cultivating a better understanding of what folks may well be up against some, not-so-far-away day. [vE]
 

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