Before 1953, sleep was widely considered a passive, coma-like state deserving little scientific curiosity, until a graduate student's observation of his own sleeping son overturned this assumption and launched an entirely new field of research.
An Assignment That Led Somewhere Unexpected
Sleep pioneer Nathaniel Kleitman had instructed his graduate student Eugene Aserinsky to study behavioral patterns during the transition into sleep by observing infants, and during these observations Aserinsky noticed substantial eye movements occurring during sleep that genuinely puzzled him. Motivated by this unexpected finding, Aserinsky restored an old electrical recording system and brought his own 8-year-old son into the lab, attaching electrodes near his eyes to measure these movements more precisely.
Extending the Discovery to Adults
After this initial observation, Aserinsky shifted his investigation to adult subjects, using the corneo-retinal potential to record eye movements with genuinely remarkable results, finding periods of rapid, jerky eye movements occurring three to four times nightly, each accompanied by increased respiratory rate and body movement. He and Kleitman published their findings in the journal Science in 1953, a paper documenting these observations across 20 adult subjects that would eventually become one of the most cited studies in sleep science.
Connecting Eye Movements to Dreaming
When researchers woke subjects specifically during these periods of rapid eye movement, participants frequently reported vivid dream recall, establishing the genuine link between this newly identified sleep stage and the dreaming experience humans had wondered about for millennia. This finding proved particularly striking to Kleitman, since the REM state's activated brain pattern directly contradicted his own earlier theory that sleep represented an entirely passive phenomenon throughout the night.
A Genuinely Complicated Collaboration
- Aserinsky later described Kleitman's role during the discovery period as genuinely tangential, despite Kleitman serving as his official thesis advisor
- William Dement, then a medical student, joined the laboratory in 1952 and helped extend the research, eventually documenting REM sleep in additional subjects using film footage of the actual eye movements
- Aserinsky initially favored naming the phenomenon Jerky Eye Movement Periods, only later settling on the REM terminology that became standard throughout the field
- The original 1953 paper proved considerably more significant for what it initiated than for its own limited scope, launching decades of subsequent research into sleep architecture
A Discovery That Redefined an Entire Field
This single observation, born from a graduate student's curiosity about an unexpected finding in infant sleep, established that sleep consists of genuinely distinct stages rather than one uniform state, a foundational insight that continues to shape virtually every area of modern sleep research.
The takeaway: The discovery of REM sleep emerged from a genuinely serendipitous observation rather than a planned investigation, illustrating how a single unexpected finding, followed carefully, can fundamentally transform scientific understanding of something as universal as sleep.