Scientists in Japan have challenged a dominant theory that the brain can only incorporate a new data stream if it’s an extension of, or structured the same as, existing senses. The new results suggest that the brain is more flexible than earlier studies suggest.
By coupling a so-termed geomagnetic compass with electrodes placed inside the visual cortex (the neuroprosthetic device), scientists have successfully allowed rats, with eyelids stitched shut, to navigate mazes as well as rats that could see. Through experiments, as reported by The Scientist, the researchers discovered that after just a few days, the “blind” rats fitted with the neuroprosthetic device could find food in a T maze as well as sighted rats. In addition, after the rats had learned the maze, they could navigate it even if the device was only turned on for a brief period before they entered, then silenced during the trial.
With the device, when the compass recognized that a rat had turned its head toward the north, an electrode stimulated the left visual cortex. When the animal turned to the south, a separate electrode stimulated the right visual cortex.
The researchers hope their results in rats might one day inform the development of similar devices for humans. Understanding one’s place in an environment will be key to successful navigation, for without an ability to perceive their orientation, people who are blind have difficulty in getting around.
The study was carried out at the University of Tokyo. The findings have been published in the journal Current Biology. The research is titled “Visual cortical prosthesis with a geomagnetic compass restores spatial navigation in blind rats.”
