Our visual system evolved to recognise objects from any angle: a tiger facing left is the same tiger facing right. This 'mirror invariance' is useful in nature but a trap for reading, where b and d, or p and q, are different letters. Learning to read means unlearning that symmetry, which is why mirror writing is so common in young children.
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.