
Year 11 Colloquium Session: Why do we dream?
In 1953, sleep researchers identified – for the very first time – distinct episodes during sleep associated with dreaming. Owing to what they described as a ‘hurricane’ of ocular activity during this phase, they called it rapid eye movement sleep or REM for short. Yet remarkably, just over 70 years on, there is still no consensus over the function of REM or why we dream.
Building on a talk last year about the scientific method, the Year 11 Colloquium set about identifying as many alternative hypotheses to explain the existence of REM sleep as possible. Within five minutes they’d identified most of the competing ideas.
Biology teacher Dr Henry Nicholls then gave an overview of several of these alternative hypotheses. Given how much time newborn infants spend in dreaming sleep, REM is likely to play an important role in brain development. Recent studies also provide clear evidence of “synaptic pruning” during REM in adult brains, a process analogous to editing that involves strengthening the connections between some neurons and weakening or erasing others that probably plays an important role in memory. There are several well-known examples of the Eureka-like power of dreams, including August Kekulé’s vision that cracked the structure of benzene, Dimitri Mendeleev’s brilliant periodic table of the elements and Paul McCartney’s Yesterday, one of the most covered songs in the history of recorded music.
Given the relatively high proportion of threatening scenarios in dreams (compared to waking life), several Year 11 students suggested that dreams might also be the brain’s way of creating a safe, virtual world in which to rehearse dangerous situations. This is a great hypothesis, and one that’s difficult to disprove.