On melatonin

I recently started reading an interesting book on learning languages, Language is Music, though I didn't remember the author's name. She's a woman from Russia who grew up in the United States, in California. I don't know what age she emigrated. Apparently she was old enough to retain her Russian but young enough to pick up English. And she now speaks six or seven other languages as well, including Spanish and Portuguese. She believes that one reason she finds it easy to hear the sounds of other languages is that she had a peculiar eye condition where she uses only one eye at a time, so always see the work in two dimensions. Both eyes work, but not at the same time - they switch back and forth. She doesn't advocate taking melatonin to learn languages, but to listen to it a lot through songs, radio, TV and movies.