The field of prosthetics, or creating and fitting artificial body parts, has provided humans with many innovative replacements, from functioning limbs that replace those lost in combat to devices that restore hearing in people who are deaf.
But in a radical departure, scientists say they've now given lab rats an extra ability the animals didn't have before: They can sense infrared light, which is normally invisible to rats (and to many other animals, including humans).
Typically, researchers design neurological prosthetics "to restore a motor function lost to lesion or damage of the central nervous system," Eric E. Thomson, a neurobiologist at Duke University in Durham, N.C., said in a press release.
"This is the first paper in which a neuroprosthetic device was used to augment function, literally enabling a normal animal to acquire a sixth sense," Thomson said of his research, which was published in the journal Nature Communications.
In the study, scientists at Duke trained a group of rats to visit feeding ports whenever a bright, visible light flashed on. The rats were then outfitted with an infrared sensor connected to the part of their brain that senses touch, according to PopSci.
Would the rats then "feel" the presence of infrared light that they couldn't see with their eyes? Sure enough, when the feeding ports flashed a normally invisible infrared light, the trained rats would scurry over to the infrared feeding port for their reward, according to the BBC.
To test the rats' perception, the scientists put the animals into a chamber with several feeding ports and switched the ports that would flash an infrared signal. And within a matter of days, the rats were able to choose the correct feeding port with 100 percent accuracy, the Telegraph reports.
In other recent advances, scientists have created a prosthetic device that allows a woman with quadriplegia to control a robotic arm using just her mind. And prosthetic retinal stimulators have been used to give vision to blind mice.
Scientists are excited this latest research might someday allow human beings who have lost a sense like vision to regain a portion of that sense.
"What we did here was to demonstrate that we could create a new sense in rats by allowing them to 'touch' infrared light that mammals cannot detect," Dr. Miguel Nicolelis, co-author of the research paper and co-director of the Center for Neuroengineering at Duke, told the Telegraph.
"This suggests that, in the future, you could use prosthetic devices to restore sensory modalities that have been lost, such as vision, using a different part of the brain," Nicolelis said.