George Borjas and Kirk Doran of Harvard and Notre Dame, respectively, studied the rate of published works in the years following a mathematician's receipt of the Fields Medal and found a significant productivity drop in the 20 years following a medal win. Compare the output of the medal-winners to that of the contenders who didn't take home the prize:
So do rewards make us rest on our laurels? Kind of. Business Insider cites the "wealth effect" at work -- how new opportunities due to prestige can make a winner more likely to opt for leisure activities -- but also the idea that winners tend to take bigger research risks in the future. So a top performer may increase his leisure after a significant accolade, but he's also more likely to go outside his comfort zone and take bigger intellectual and cognitive risks compared to lifelong specialists.