Tuesday, September 27, 2011

Rats get partly 'robot brain'

A new step in the development to create fully-fledged bionic robots, as scientists have replaced part of the rat brain by a chip, which is supposed to mimic its functions. The synthetic implant, which replaces the part of the brain called cerebellum, appears to be functioning in anesthetized rats. Researchers from Tel Aviv University showed that animals in which the cerebellum was replaced by the chip could be taught a reflex. Normally, the cerebellum is needed to coordinate reflex behavior, showing that the digital brain is functional. A first step in replacing brain material with a 'robot version', and something we might harness for patients with brain damage, for example due to stroke.

In the experiments, rats were anesthesized, whereafter their cerebellum was disabled. The chip is connected to the brain with electrodes, in order to receive and send signals to other parts of the brain. The cerebellum, nicknamed 'small brain' because it is a separate piece of brain tissue at the back of your head, is involved with coordination, timing and precision of movement. Therefore, the scientists tried to teach the unconscious rat a reflex, that requires certain motor skills to test the functionality of the chip. While a sound was being played, a puff of air was blown into the eye of the rat, causing the animal to blink. Because the sound is played at the same time that a puff of air was delivered to the eye, the rats 'learned' to associate the sound with the reflex of blinking. Because the cerebellum was disabled, this showed that the chip can be used to take over functions that are normally attributed to this part of the brain.

Naturally, the cerebellum does more than just help you with blinking your eye. Future generations of the brain chip could be used for more complex motor movement. For this, scientists need to model more parts of the cerebellum. Because the brain structure is relatively simple, this could well be possible. In addition, the chip needs to be tested in a conscious animal, which is likely to be much harder.

The synthetic brain is an important step in replacing dead brain material with a computer version. Patients that suffered from a stroke often have damage that can not be repaired, as large parts of the brain have been shut down. Replacing dead tissue with a chip can possibly restore brain functions that are often impaired in stroke patients, such as speech, movement, coordination and cognitive functions. Of course, before this is possible, scientists would have to model parts of the cerebrum, the 'big brain', and integrate them into a chip, something that is likely to be decades away.

Would it be possible to replace our brain completely with a computer version? I don't know, but this is certainly a first step.

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