The latest Silicon Valley arms race is a contest to build the best artificial brains. Facebook, Google and other leading tech companies are jockeying to hire top scientists in the field of artificial intelligence, while spending heavily on a quest to make computers think more like people.

They're not building humanoid robots — not yet, anyway. But a ­number of tech giants and start-ups are trying to build computer systems that understand what you want, ­perhaps before you know you want it.

"It's important to position yourself in this market for the next decade," said Yann LeCun, a leading New York University researcher hired to run Facebook's new A.I. division in December. "A lot is riding on artificial intelligence and content analysis, and on being smarter about how people and computers interact," he said.

Artificial intelligence programs already can recognize images and translate human speech. Tech researchers want to build systems that can match the human brain's ability to handle more-complex challenges — to intuitively predict traffic conditions while steering automated cars or drones, for example, or to grasp the intent of written texts and spoken messages, so they can better anticipate what kind of information, including ads, users want to see.

Facebook has recruited several well-regarded A.I. scientists, including one from Google, in recent months. Google has been working on artificial intelligence for several years, enlisting such prominent researchers as Stanford's Andrew Ng and the University of Toronto's Geoffrey ­Hinton to help build computer systems known as "neural networks," which are capable of teaching themselves.

But Google wants to do more, so it paid a reported $400 million in January to buy DeepMind, a British start-up said to be working on artificial intelligence for image recognition, e-commerce recommendations and video games. In March, Facebook CEO Mark Zuckerberg invested personally in Vicarious, a Silicon Valley start-up working on software that can recognize — and draw — images of animals or other things.

"In the last 18 months, every venture capital firm I know has made at least one investment" in artificial intelligence, robotics or related ­sectors, said Raj Singh, CEO of Tempo AI, which makes a "smart calendar" mobile app that acts like a personal assistant.

Already, Google has used artificial intelligence to improve its voice-enabled search and Google Now, as well as its mapping and self-driving car projects.

"I think we're seeing a lot of exciting work going on, that crosses computer science and neuroscience, in terms of really understanding what it takes to make something smart," Google CEO Larry Page said in March.