Mimicking the human brain is fundamental to most AI research; on DeepMind's website, they say that they employ computational neuroscientists and companies such as IBM are very interested in whole brain emulation.

Mimicking the human brain is an obscure branch of AI. Most AI projects, and certainly the successful ones you've heard about, are at best inspired by stripped down models of specific isolated aspects of human thought, if they take any inspiration from the human brain at all.

DeepMind for example is reinforcement learning on top of modern machine learning. Machine learning may make use of neural networks, but beware of the name: neural networks only casually resemble the biological structure from which they take their name. DeepMind doesn't work anything like the human brain, nor does Watson, Deep Blue, or self driving cars.

Learn a bit about practical AI and neuroscience and you'd be surprise how little they have in common.