The mammal brain is an amazingly flexible organ. A new study reveals that blind rats can learn to navigate a maze almost as good as rats with perfect eyesight.
The findings, published in the Current Biology journal, may one day lead to helping blind humans move about more freely and safely.
"The most remarkable point of this paper is to show the potential, or the latent ability, of the brain," said Yuji Ikegaya of the University of Tokyo. "That is, we demonstrated that the mammalian brain is flexible even in adulthood — enough to adaptively incorporate a novel, never-experienced, non-inherent modality into the pre-existing information sources."
It seems the brain somehow compensates for vision loss by drawing on an allocentric sense, which lets animals and people know the position of their body in relationship to their environment.
In the study, the missing sense was recreated by headgear featuring a geomagnetic sensor that connects to the same kind of digital compass used in smartphones.
The sensor detected the position of the rat's head, providing electrical stimuli to indicate direction, such as north or south, according to Ikegaya and fellow researcher Hiroaki Norimoto. Using the wearable gear, the blind rats were trained to hunt for food in a maze. Within a short timeframe, they had learned to use the geomagnetic data to solve complicated mazes.
The study involved 20 trials over nine consecutive days. By the fifth day of testing, the rats were choosing the correct turn 90 percent of the time.
The results show that performance and navigation skills quickly became on par with normal seeing rats, through the restoration of allocentric sense to the blind rats. The proponents were surprise how the rats were able to comprehend the new sense and were able to carry out behavioral tasks in a matter of two or three days.
The findings could lead to the development of similar sensor technology for humans who are blind or dealing with severe eyesight issues. The sensors could tap ultraviolet radiation or ultrasound waves.
The study also illustrates how the potential of the brain is going largely untapped.
"Perhaps you do not yet make full use of your brain," Ikegaya said. "The real sensory world must be much more 'colorful' than what you are currently experiencing."
