Does Everyone Dream?

From Discover:

Everyone dreams – even people who believe that they “never dream” and can’t remember any of their dreams. That’s according to a group of French researchers writing in the Journal of Sleep Research: Evidence that non-dreamers do dream. In questionnaire surveys, up to 6.5% of people report that they ‘never dream’. Although most of these people report having dreamed at some point in the past, roughly 1 in every 250 people say that they can’t remember ever dreaming – not even once.

But is it possible that these “non-dreamers” do in fact have dreams, but just can’t remember them? To study this question, Herlin et al., authors of the new paper, looked at people with REM sleep behavior disorder (RBD), a condition in which patients make movements, sometimes violent ones, while they sleep. Sometimes these movements are accompanied by speech. The movements seen in RBD are often quite complex and, interestingly, they seem to correspond to the content of the dreams that patients are experiencing. At least some of the actions seen in RBD are ‘acted out’ dreams. Herlin et al. report that some RBD patients report never dreaming: out of 289 diagnosed RBD cases, 2.7% reported that they had not dreamed for at least 10 years, and 1.1% said that they had never dreamed ever. However, in many cases their actions during sleep (captured on video in the sleep clinic) suggested that they were dreaming.

More here.