Your eyes don't glide along this line. They make about four small jumps per second, called saccades, separated by pauses of roughly a quarter of a second. During each jump, vision is largely suppressed. At each stop only a few letters are sharp, mostly to the right of the fixation point in English. Your brain stitches it all into smooth text.
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.