Learning of new knowledge during sleep
Without sleep communication, it is obviously not possible to transport new knowledge into the dreams of a sleeping person. Of course, knowledge and skills learned during the day are rehearsed during sleep and sleep has been shown by numerous studies to be very important for this, but learning information never heard before during sleep is not possible up to today. With sleep communication, this can become possible for the first time in history. Just imagine, you are a student, the night before the exam you go to sleep, and during sleep you just learn the necessary knowledge to succeed in the exam! A very simple experiment for this can be easily conducted even now already: Instead of sending random math tasks into the dream world, new information can be sent to the dreamer, for example the most important events of the 10th century. After awakening the dreamer would be tested on the new knowledge learned during sleep. This could further be extended to a more interactive way of learning, since sleep communication works in both directions, making teaching with a teacher-student concept possible. With further advancement in sleep communication, it might even be possible one day e.g. to dream of being in the ancient Rome, having Julius Caesar as a private tutor for learning Latin (or, being taught the French language by Asterix & Obelix).