Talk of the Nation

Chances are, you've fallen victim to earworms — pesky songs or melodies that get stuck in your head and just won't get out.

Research suggests that there are psychological reasons why some songs are more likely to stick, including memory triggers, emotional states, and even stress. Some researchers hope to better understand why this happens and figure out what, if anything, music memory can teach psychologists about how to treat patients dealing with memory loss.

The New Horizons Mission blasted off toward Pluto in 2006; it's on course to arrive in Pluto's neighborhood in 2015. Mission leader Alan Stern discusses the journey of the spacecraft, and why he thinks Pluto is still a planet. Plus, the mission to get Pluto on a commemorative stamp.

Reporting in Nature, researchers write they have deciphered the genetic code of the gorilla, the last of the great apes to have its genome sequenced. Study co-author Aylwyn Scally discusses what the data reveal about the evolution of humans and other apes.

When you crunch into a potato chip or take a spoonful of chocolate mousse what you experience is more than just the taste of the food. In her book Taste What You're Missing, Barb Stuckey discusses why truly experiencing food involves all five senses and offers tips on how to get more enjoyment from your next meal.

Reporting in Cell Metabolism, researchers write that when people who lead relatively sedentary lives worked out the DNA in their muscle fibers changed almost immediately. Scientists also found caffeine had the same effect on isolated rodent muscles. Study co-author Juleen Zierath discusses the DNA modifications.