In 1978, researchers slipped an invented colour word, 'chromium', into an instruction for 3- and 4-year-olds: 'Bring me the chromium tray, not the red one.' For many children, that single exposure left a lasting trace days later. Known as 'fast mapping', it helps fuel the vocabulary explosion of early childhood.
In Kuşköy, a mountain village in northern Turkey, people talk across valleys by whistling Turkish. A 2015 study showed that whistled Turkish draws on both hemispheres fairly evenly, whereas spoken Turkish relies mostly on the left. The physical form of the signal, it turns out, matters to the brain.
Speech has no gaps between words. In 1996, researchers played 8-month-old babies a continuous stream of made-up syllables for just two minutes. The infants picked out the 'words' by tracking which syllables tend to follow one another. That's probability calculation, done without a calculator or any visible effort.