Human neurons. Courtesy of Heather de Rivera (McCarroll Lab) Computers have long been good at carrying out assigned tasks but terrible at learning things on their own.

Thus all the excitement around "neural networks," a breakthrough artificial intelligence technique that mimics the structure of the human brain and allows machines to learn things independently.

Tech giants are using neural networks to do some pretty impressive things.

Microsoft is using them to make instant translation real for Skype. Google's artificial intelligence learned Atari video games and then mastered the ancient game of Go, with its AlphaGo program beating the human champion Lee Sedol 4 to 1.

The first artificial neuron was created in 1943, but it's only been in the last few years that neural networks have taken off.

Neural networks are a part of an artificial intelligence revolution that's as important as the invention of the Internet itself, says University of Washington computer scientist Pedro Domingos, author of "The Master Algorithm: How the Quest for the Ultimate Learning Machine Will Remake Our World."

With neural networks, AI can learn from experience; a programmer doesn't have to write prescriptions of how to behave within the code.

"One of these artificial neurons is to a real neuron a little bit like an airplane is to a bird. At a certain level of detail, they’re very different, but the important point is that the do the same job, they both fly," Domingos says. "In the same way a neural network and a brain, they’re very different. One is made of silicon, one if made of cells, but they do the same job, which is to learn from experience."

Like the human brain, neural networks can learn by association — the Skype translator gets better at translating German to English after has done done German to Chinese.

Beyond driving cars, Google is using neural networks to create surreal electronic paintings. The pattern recognition is so advanced that Google's trippy algorithms can see the silhouette of a tree and turn it into a building or find a leaf and make it look like a bird. Meanwhile, Microsoft's neural networks are better at recognizing images than humans.

These artificial brains are only getting more important: Google chief Eric Schmidt says that they'll be behind every meaningful tech IPO over the next five years.