writes "Researchers have given lab rats the ability to sense infrared light through a brain implant. From the article, "They taught the rats to choose the active light source by poking their noses into a port to receive a sip of water as a reward. They then implanted the microelectrodes, each about a tenth the diameter of a human hair, into the animals' brains. These electrodes were attached to the infrared detectors.
The scientists then returned the animals to the test chamber. At first, the rats scratched at their faces, indicating that they were interpreting the lights as touch. But after a month, the animals learned to associate the signal in their brains with the infrared source.""Link to Original Source