A computer designed by hobbyists to look like a brain on display at a Berlin fair in 2012. What happens when we go from crude models to complete working simulations of this all-important organ? Britta Pedersen/DPA/AFP/Getty Images hide caption

itoggle caption Britta Pedersen/DPA/AFP/Getty Images

The brain edits memories of the past, updating them with new information. Scientists say this may help us function better in the present. But don't throw those photos away. iStockphoto hide caption

itoggle caption iStockphoto

Study participants were trained in practical reasoning skills like managing medications. Jorge Salcedo/iStockphoto hide caption

itoggle caption Jorge Salcedo/iStockphoto

Erick Munoz stands by a photo of his wife, Marlise Munoz, at home in Fort Worth, Texas, on Jan. 3. She is being kept on life support in a local hospital against the family's wishes. Fort Worth Star-Telegram/MCT via Getty Images hide caption

itoggle caption Fort Worth Star-Telegram/MCT via Getty Images

Researchers have only recently been able to use brain scans to detect Alzheimer's risk factors in living people. iStockphoto hide caption

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Having a perfect memory can put a strain on relationships, because every slight is remembered. Katherine Streeter for NPR hide caption

itoggle caption Katherine Streeter for NPR

A newly discovered neural circuit in the brain of the common fruit fly seems to serve as a sort of "volume control," turning up and down the perception of sound and light. Nicholas Monu/iStockphoto hide caption

itoggle caption Nicholas Monu/iStockphoto

A technique called optogenetics is being used in the laboratory to observe and control what brain circuits are doing in real time. Henning Dalhoff/Getty Images/Science Photo Library RM hide caption

itoggle caption Henning Dalhoff/Getty Images/Science Photo Library RM

Surgeons use a grid of electrodes laid on a patient's brain. They record electrical activity and can deliver a tiny jolt. Courtesy of Dr. Josef Parvizi hide caption

itoggle caption Courtesy of Dr. Josef Parvizi