- a pattern of slow brain waves, having a frequency of less than 6 cycles per second as recorded by an electroencephalograph, associated with deep sleep.
Origin of delta rhythm
First recorded in 1935–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- physiol the normal electrical activity of the cerebral cortex during deep sleep, occurring at a frequency of 1 to 4 hertz and detectable with an electroencephalographSee also brain wave
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
- A brain wave pattern originating from the forward portion of the brain and having a frequency of between 1.5 and 4.0 hertz; it is associated with deep sleep in normal adults.delta wave
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.