Theta wave
Theta waves were a type of brain waves seen on an EEG that were usually experienced just before or after a period of deep sleep.

In 2154, Phlox determined that Jonathan Archer's theta wave levels were fine while he was comatose. ()

The Altonian brain teaser responded to neural theta waves. ()

In 2367, Doctor Beverly Crusher tried inducing theta waves into the entorhinal cortices of the  to help them achieve REM sleep, with no effect. ().

Cortical inhibitors were used to control theta wave activity. ()

In 2373, B'Elanna Torres' theta wave pattern indicated she was experiencing implanted memories, having received them telepathically from Jora Mirell. ()

In 3189, an atomic scan was performed on the brain of . The results of the scan revealed that her theta wave was symmetrical with a frequency range of 4-7 Hz. ()

External link 
 
Physiology
de:Theta-Wellen