Some apps, like CBT-I Coach, use proven scientific methods to help people manage their underlying sleep challenges. Mary Mathis/NPR hide caption

If you like sudoku, go ahead and play. But staying sharp means using many parts of your brain. Yasuyoshi Chiba/Getty Images hide caption

Facebook CEO Mark Zuckerberg speaks during the annual F8 conference in San Jose, Calif., on May 1. California passed legislation that would allow users to sue for damages for data breaches like the one Facebook recently suffered. Josh Edelson/AFP/Getty Images hide caption

Sylvester performs with his band at the Los Angeles club Whisky a Go Go in 1972. Richard Creamer/Michael Ochs Archives/Getty Images hide caption

Faith-based groups from both sides of the political spectrum are working to inspire voters for the midterms. A man listens as Black Voters Matter co-founder LaTosha Brown speaks at a church as part of The South Rising Tour, aimed at getting more voters to the polls. John Bazemore/AP hide caption

Kevin Scott, a South Dakota farmer and secretary of the American Soybean Association, welcomed the deal to replace NAFTA because it preserved the market access established under the previous agreement. Courtesy of Jannell Scott hide caption

A man sits draped in a rainbow flag in a nightclub in Bucharest, Romania on Sunday after learning election results. A referendum to redefine marriage as between a man and a woman failed to attract the minimum number of voters and the result was invalidated. Andreea Alexandru/AP hide caption

Pope Francis leaves the Paul VI hall at the end of his meeting with youths attending the synod at the Vatican on Saturday. The three-week meeting will likely be dominated by what many analysts call Catholicism's worst crisis since reformation. Gregorio Borgia/AP hide caption