In many of the oldest Greek inscriptions, the text switches direction on every line: right to left, then left to right, and so on, with the letters mirrored as they turn. This style is called boustrophedon, Greek for 'turning like an ox' at the end of a furrow. The law code of Gortyn, on Crete (5th century BCE), is a famous example. Left-to-right writing only became the rule later.
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.