Exploring and developing the concept of the dream as a threat monitoring-alerting mechanism

  • Rupert Harwood (Author)

Identifiers (Article)


Summary. It is not clear that established dream theories adequately explain the purpose of something that accounts for such a substantial percentage of our time. Gewargis’s innovative theory - that dreams function to safeguard the organism during sleep - seems plausible and to have the potential to make an important contribution to a better understanding of why we dream. There are, however, a number of possible problems with it. In particular, the published literature is not used to substantiate the empirical claims upon which the theory is built; and this could be a major issue, as a some of these claims seem to be at variance with current scientific knowledge and/or to have limited face validity. This comment article draws upon the neurology literature to critique and suggest amendments to Gewargis’s theory; and proposes additional hypotheses relating to why and how dreams might act as a monitoring-alerting mechanism and protect the sleeper from a range of internal and external perturbations during REM and NREM sleep; and not just, as Gewargis appears to suggest, guard against inadequate blood flow to the brain or “oxygen-deprivation” to the lungs during REM sleep. A central argument in this comment piece is that to perform a range of functions, such as memory processing, the dream is where the sleeper’s consciousness is focused for much of the time asleep, and so it is also where the alerting-arousal messages need to be presented and processed during that time. In other words, and at variance with what Gewargis proposed, we don’t dream so as to provide a sleep defence mechanism, but a Dream Sleep-Defence Mechanism (DSDM) is needed because we dream. It addition, it argued that dreams - including through the use of broad categories (and, in particular, potential danger/not potential danger), rather than representational reflections of the reality in question - provide a cortical resource efficient mechanism. It is recognised, however, that support for a dream sleep defence mechanism is at best circumstantial and that the idea needs to be tested in experimental studies if it is to move beyond conjecture.  


Dream, sleep, REM, NREM, cortical, threats, hypoxia, defence
How to Cite
Harwood, R. (2021). Exploring and developing the concept of the dream as a threat monitoring-alerting mechanism. International Journal of Dream Research, 14(1), 156–164. https://doi.org/10.11588/ijodr.2021.1.76927