Comparative Analysis of REM and NREM Sleep in Mammals, Reptiles, and Cephalopoda with Relations to Dreaming

Humans cycle through NREM and REM sleep, with dreaming occurring in both stages but more frequently during REM. Whether non-human animals experience the same sleep cycles and therefore dream remains uncertain. By reviewing research on sleep behaviors and experiments in mammals, reptiles, and cephalopods, the author examines evidence for REM/NREM sleep and dreaming in animals. Establishing whether animals dream could help neuroscientists better understand human dreaming, its purpose, and the meaning of dream content.

Study at a glance

Abstract

The normal human sleep period has two main cycles: REM [rapid eye movement] and NREM [non-rapid eye movement].Typically, people go through the three stages of NREM sleep, then to the one stage of REM.Human dreaming occurs during both cycles, more frequently during REM.Whether non-human animals go through the same sleep cycle is still in question, and the answer could determine whether animals dream or not.Analyzing sleep-enacting behaviors, sleep experiments, and other research done with non-human mammals, reptiles, and cephalopods will help the author conclude whether animals go through REM/NREM sleep and dream.Establishing a definite answer in the future will allow neuroscientists to delve deeper into the measurement of dreaming in humans, the purpose of dreaming, and the true meanings of dream content.