IMG William Dement-Stanford photo

William C. Dement (Stanford University photo)

STANFORD, California — Dr. William C. Dement, an influential sleep researcher who had his roots in Wenatchee, died on Wednesday. He was 90.

Dement’s research at the University of Chicago in the 1950s illustrated the relationship between dreaming and rapid eye movement. Later, he broke new ground in the study of narcolepsy, sleep disorders, and sleep apnea, and discovered the five stages of sleep using EEG monitors to record patients’ brain activity.

Dement was born in Wenatchee in 1928. first studied at the University of Washington, where he also played jazz bass. He spent the bulk of his academic and research career at Stanford University, and wrote several books on his field, including The Promise of Sleep (1999).

His death was announced by the Sleep Research Society, an organization he helped found in 1961.