There's a very fundamental clash. It's almost like a religious debate. They help Saffran show how infants can find word boundaries in a long stream of speech. The nonsense language is needed to guarantee the babies never encountered the words before. By using different speakers and flashing lights to grab attention in her lab, Saffran can carefully observe when the babies' attention is held and when it's diverted.
Kids love repetitive stuff, like rhymes and babble, and they are fascinated with flashing lights.
In her new lab at the Waisman Center, Saffran can use the same arrangement to probe all sorts of related questions about the language mystery. You don't have to do anything special. In nature, Saffran finds an interesting parallel in the diverse songs of birds. Each species of bird has its distinct songs, like secret handshakes shared only with their species. It is so clinically precise, it clearly suggests a firm genetic imprint honed through centuries of evolution.