This is an ultra realistic, highly detailed Portrait of Sylvia by South Korean 3D artists Jung-won Park, created using Autodesk Maya, Mental ray, Pixologic ZBrush, and Adobe Photoshop.
CGRecord has a breakdown of his render layers which is really interesting.
This is just so realistic that it looks too real. Uncanny Valley doesn’t exist anymore!
The software used in Portrait of Sylvia
Portrait of Brian? NoneCG Models
If you are interested in working with prebuilt models of humans, you might want to check these out from NoneCG. These are for 3ds Max, not Maya.