Albert Einstein is considered to be one of the most intelligent people who ever lived, so researchers are curious about what made his brain tick.

Photographs taken shortly after his death, but never before analyzed in detail, reveal that Einstein's brain had several unusual features, providing tantalizing clues about the neural basis of his extraordinary mental abilities.

Now, anthropologist Dean Falk of Florida State University in Tallahassee and her colleagues have studied photographs from the National Museum of Health and Medicine in Silver Spring, Maryland.

The most striking observation, says Falk, was "the complexity and pattern of convolutions on certain parts of Einstein's cerebral cortex," especially in the prefrontal cortex, and also parietal lobes and visual cortex.

The prefrontal cortex is important for the kind of abstract thinking that Einstein would have needed for his famous thought experiments on the nature of space and time, such as imagining riding alongside a beam of light. The unusually complex pattern of convolutions there probably gave the region and unusually large surface area, which may have contributed to his remarkable abilities.

Read more from Nature journal.