View Full Version : Stealth sharks to patrol the high seas

03-02-2006, 10:10 PM
IMAGINE getting inside the mind of a shark: swimming silently through the ocean, sensing faint electrical fields, homing in on the trace of a scent, and navigating through the featureless depths for hour after hour.

We may soon be able to do just that via electrical probes in the shark's brain. Engineers funded by the US military have created a neural implant designed to enable a shark's brain signals to be manipulated remotely, controlling the animal's movements, and perhaps even decoding what it is feeling.

The team is not the first to attempt to control animals in this way. John Chapin of the State University of New York Health Science Center in Brooklyn has used a similar tactic to guide rats through rubble piles (New Scientist, 25 September 2004, p 21). Chapin's implant stimulates a part of the brain that is wired to their whiskers, so the rats instinctively turn toward the tickled side to see what has brushed by. Chapin rewards that response by stimulating a pleasure centre in the rats' brains. Using this reward process, he has trained the rodents to pause for 10 seconds when they smell a target chemical such as RDX, a component of plastic explosives.

Mavoori's implant can also stimulate one part of the brain in response to activity in another, and has a microchip that can interpret the neural signals and send a message to another part of the brain or a muscle accordingly. He and his colleagues believe such an implant might ultimately help humans compensate for lost nerve function caused by injury or disease.

They have found that when a monkey is free to move around, sets of neurons controlling opposing muscle groups - those that extend and flex a joint - are both active throughout many movements. However, when a monkey is restrained in a chair and taught to extend its hand for a food reward, say, only the neurons that control the extensor muscles tend to be active.

Understanding this difference may be vital in creating a muscle-stimulating prosthesis to restore movement to a limb paralysed by nerve damage. For some loose movements, such as gently extending your arm in and out, sending signals to opposing muscles in turn works quite well. However, for movements that require some rigidity in the joint, such as inserting a book into a bookcase, you need to engage opposing muscles simultaneously. A successful neural prosthesis will need to mimic both patterns.


Interesting article


03-02-2006, 11:19 PM
Remote-controlled sharks:


03-03-2006, 01:36 AM
Roshi, maybe they are on to something here eh?

One thing can hopefully lead to another. Guess this is kind of like robotics. :dontknow:[/