Delta Waves

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Delta waves are the slowest brain waves in humans. They are high amplitude neural oscillations with a frequency between 0.5 and 4 hertz. Delta waves are usually associated with the deep stage 3 of NREM sleep, also known as slow-wave sleep.

Delta waves are most often found in infants and young children, and are associated with the deepest levels of relaxation and restorative, healing sleep. They are also prominently seen in brain injuries, learning problems, inability to think, and severe ADHD.

Delta waves are abnormal in the awake adult. They may exhibit abnormal activity in various conditions such as traumatic brain injury or dementia. Focal delta may be the result of a lesion or tumor or may indicate damage from a stroke.

Delta waves can be recorded with electroencephalography.