The discovery of REM sleep.
The impetus to pursue the study of ocular motility in sleeping adults was derived from a previous study conducted by the author on infants. He noted through visual observation alone that there was an approximate twenty minute interlude of complete ocular quiescence during each hour of sleep. This period of quiescence was termed 'No Eye Movement Period' or 'N.E.M. Period', and it was the intent of the author to ascertain what effect age would have on the distribution of N.E.M. periods during sleep. In the latter part of 1951, the first continuous all-night recording of ocular motility in sleep using a combined EEG and EOG technique was conducted on the author's eight year old son. Instead of N.E.M. Periods, what he found were aproximately twenty minute periods of vigorous ocular activity including saccadic-like eye movements. Although he ultimately termed these epochs as 'REM Periods', his initial intent was to name them 'Jerky Eye Movement Periods' or "JEM Periods'. Ironically, some three decades later he found that a mathematical measure of jerkiness was a better discriminator than velocity in distinguishing REMs from waking saccades. Kleitman, who was the thesis advisor, played the role of skeptic during the REM discovery and demanded unassailable proof of the existence of REM. His feelings had to be ambivalent inasmuch as the REM state, with its concurrent activated cerebral cortex, negated his own theory that sleep was a completely passive phenomenon.