I think the best article on this is Mark Solms 2000 "Dreaming and REM sleep are controlled by different brain mechanisms"[0]. Solms and a couple of coauthors h

I think the best article on this is Mark Solms 2000 "Dreaming and REM sleep are controlled by different brain mechanisms"[0]. Solms and a couple of coauthors have an article this year, "Dreaming in Neurological Disorders"[1], which is also great although I don't think it directly answers your question. My sense is that it is still being debated if there are differences in the types of dreams that happen in different stages or not. I couldn't find it last time I looked, but some research somewhat recently found that medically extinguishing REM sleep did not produce a detectable change in dream reports. Other studies seem to show that there may be differences. [0] http://neuro.bstu.by/ai/To-dom/My_research/Papers-2.1-done/Cognitive-S/Consciousness/For-icnnai-2010/2/Ref/download.pdf http://neuro.bstu.by/ai/To-dom/My_research/Papers-2.1-done/C... [1] https://twin.sci-hub.ac/cd77f4d5f6111801eee90b66a3ac13ee/solms2017.pdf https://twin.sci-hub.ac/cd77f4d5f6111801eee90b66a3ac13ee/sol...