Smithsonian has done a nice profile of Tilly Edinger, one of the most important paleontologists of the twentieth century: “The Woman Who Shaped the Study of Fossil Brains”.
Tilly Edinger was one of those rare people who knew exactly what she wanted to do. After reading Othenio Abel’s Principles of Vertebrate Paleontology, she had her calling: the study of ancient animals through their bones. She would go on to become one of the most significant paleontologists of the 20th century, and the first woman to be elected president of the Society of Vertebrate Paleontology. Not only that, but she would found an entirely new field of inquiry—paleoneurology, or the study of fossil brains.
The study of ancient endocasts in hominins is frustrating because of how little information is preserved on the outside surface of the brain. I’ve gotten a good introduction to the subject with the Homo naledi endocast material.
With some other lineages of vertebrates, there is a bit more to say, and Edinger made significant discoveries about the evolution of brain form in many of those lineages.