NEWS | January 29, 2019

How much sleep do teens need?

UC Davis sleep study finds promising basis for measuring effects of sleep time


One major obstacle to determining how much sleep adolescents need is the lack of a reliable biological test to measure sufficient sleep.

UC Davis students Pari Dhayagude, Natalie Pandher, Matthew Sam and David Garrett apply EEG electrodes during training for a Sleep Laboratory study. UC Davis students Pari Dhayagude, Natalie Pandher, Matthew Sam and David Garrett apply EEG electrodes during training for a Sleep Laboratory study.

But new research by Irwin Feinberg and Ian G. Campbell, of the Department of Psychiatry and Behavioral Sciences at UC Davis Health, has found that changes in brain physiology when asleep and awake, as measured by electroencephalogram (EEG) power density, holds promise as a noninvasive approach to determine if individuals are getting enough sleep time for the brain to function at its best.

“This is one of the first demonstrations of an effect of sleep duration on waking brain electrophysiology,” Feinberg said. “If we obtain similar results in adults, we believe the intensity of waking brain waves, easily measured by computer, could serve as a general index of biologically sufficient sleep. 

A waking EEG recording from UC Davis Sleep Lab’s study of how sleep-need changes across adolescence.  More sleep in adolescents aged 10-14 resulted in stronger waking EEG patterns.

The results of their three-year study, conducted in 77 adolescents aged 10 to 14, appears in the current issue of PLOS One. The approach may also provide a way to assess sleep disorders.

"Our data show that longer sleep produces more intense brain waves when awake,” said Irwin Feinberg, professor and director of the Sleep Laboratory at UC Davis Health.

For the study, researchers modified the time-in-bed schedules for participants so that they slept for a specified number of hours for four consecutive nights each week in their own beds. The amount of sleep time included 10, 8.5 and 7 hours. Electrodes placed over the central and occipital regions of their scalps captured brain activity.

Project Scientist Ian Campbell assesses data with Research Associates Zoey Zhang and Alejandro Cruz

At the end of each week, the adolescents spent a weekend day in the laboratory for sleepiness and performance tests, including waking EEG recordings.

"We found shorter sleep times significantly decreased waking EEG power in a wide range of frequencies,” Campbell said. “While more research is needed to determine the extent of this phenomenon, if this test proves sensitive and specific, it could have a range of applications in research on sleep and cognition, aging and hypnotic efficacy.”

Campbell added that the test could also help determine if teens are getting adequate sleep at different ages or if people in the military and public service are getting enough sleep to perform important tasks.

Enroll in the next UC Davis Adolescent Sleep Study
The UC Davis Sleep Lab needs participants aged 15 to 20 years old and live in Davis, Dixon or Woodland. The participants need to be in the area for the next three years, beginning in February. The researchers aim to recruit 100 subjects, evenly distributed between males and females. Study details are online or contact the researchers at 530-752-7216 or