Lively — almost childlike — the 70-year-old men skipped out of a monastery one fine morning. They’d just spent five days living in the old building, under observation by Harvard researcher Ellen Langer. Now the men were leaving for home —smiling, happy, active, laughing. It was the fall of 1981, the first year of Ronald Reagan’s administration, and the men had the same sunny abandonment associated with our 40th president — who, coincidentally, was exactly their age.

But these seniors, as part of Langer’s research project, had just been through a time warp. Their brains had spent the past workweek not in 1981, but in 1959. The monastery was filled with songs like "Mac the Knife" and the "Battle of New Orleans." On the black-and-white TV, the Boston Celtics beat the Minneapolis Lakers in the finals (yes, Minneapolis Lakers) and Johnny Unitas played for the Baltimore Colts ... President Eisenhower had just signed into law the Hawaii Admission Act, creating the 50th state.

That walk down memory lane was the reason the men were so happy as they left the monastery. Waiting for the bus to take them home, a few entered into a spontaneous game of touch football — an activity most had not done for decades.

You might not have recognized these men 120 hours previously. They were shuffling, with poor vision, hearing, and memory; some of the men required canes to walk into the monastery. A few could not carry their suitcases up to their rooms. Langer and her team had poked and prodded the men’s bodies, and assessed their brains. These baselines proved one thing: before entering the monastery, the men were stereotypically old, as if ordered from Central Casting under the request “Eight infirm seniors, please.”

But they didn’t stay infirm.

Read the excerpt from Dr. John J. Medina's book Brain Rules for Aging Well at The Naked Scientists.