Of mind over matter

If machines become safe enough to interface with human brain then paralyzed people can start walking with prosthetic limbs.

A latest study of interaction between brain and machine shows that learning to move a cursor of computer or to control robotic arm with thoughts is not much different from learning any game. Computer interfaces that translate thoughts into movements are given new set of instructions every day.

Training the mind to move the cursor

Experiments shows that just by using one set of instructions and small number of brain cells which delivers the instruction, monkeys learned to performing same computer cursor movements each day. This is the first demonstration that the brain can form a motor memory to control a disembodied device in a way that mirrors how it controls its own body.

This surprising and dramatic results show that the brain is smarter than we thought. To perform the experiment electrodes are implanted directly into the brain to record activity from a population of about 100 cells that involved in helping the movements. The activity pattern of those cells in animals when they move their hand or arm is recorded. Later the limb is immobilized, and researchers tried to predict what the animal wants to do with it by looking at the cells activity, that patterns is then sent to computer decoder algorithm which can translate the brain signal into commands that machine can understand. Due to the variable pattern caused by the motion of electrodes and changes in brain cells made researchers to assume that a new population of cells would be in control of the movement every day. They recalibrated the decider each day and subject has to relearn the task.

Researchers wondered what would happen if they keep the decoder constant as it measured the activity of just few neurons. Then a team trained two monkeys to move cursor to the marked location with joy stick. In the beginning the trajectory of movement observed appeared random but over a period of time cell firing stabilized and monkeys developed a stable mental pattern.