A study published in the journal Brain[22] in September 2013 analyzed Einstein's corpus callosum - a large bundle of fibers that connects the two cerebral hemispheres and facilitates interhemispheric communication in the brain - using a novel technique that allowed for a higher resolution measurement of the fiber thickness. Einstein's corpus callosum was compared to two sample groups: 15 brains of elderly people and 52 brains from people aged 26. Einstein was 26 in 1905, his Annus Mirabilis (Miracle Year).