Workers try to remove some of the 11 million gallons of oil spilled by the Exxon Valdez off Alaska in 1989. The ship's third mate may have been up for 18 hours before the accident. Rob Stapleton/AP hide caption

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

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Playing this game won't make you feel older, unless you're already getting up there in age. iStockphoto.com hide caption

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Strenuous mental exercise like reading difficult books, solving tricky math problems — or, maybe, playing the right video game — can help keep a healthy brain sharp, research suggests. Images.com/Corbis hide caption

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