Smart, successful, and well-connected: a good description of Albert Einstein … and his brain. The father of relativity theory didn’t live to see modern brain imaging techniques, but after his death his brain was sliced into sections and photographed. Now, scientists have used those cross-sectional photos to reveal a larger-than-average corpus callosum—the bundle of nerve fibers connecting the brain’s two hemispheres. Researchers measured the thickness of the famous noggin’s corpus callosum (the lighter-colored, downward-curving region at the center of each hemisphere, above) at various points along its length, and compared it to MRIs from 15 elderly men and 52 young, healthy ones. The thickness of Einstein’s corpus callosum was greater than the average for both the elderly and the young subjects, the team reported online last week in the journal Brain. The authors posit that in Einstein’s brain, more nerve fibers connected key regions such as the two sides of the prefrontal cortex, which are responsible for complex thought and decision-making. Combined with previous evidence that parts of the physicist’s brain were unusually large and intricately folded, the researchers suggest that this feature helps account for his extraordinary gifts.