In the heart a delta wave in the ECG is seen in Wolff-Parkinson-White syndrome.

Tare delta. These are less than 4 Hz and occur in deep sleep and also during experiences of "empathy state". Delta waves are involved with our ability to integrate and let go and reflects unconscious mind.

It is the dominant rhythm in infants up to one year of age and it is present in stages 3 and 4 of sleep.

It tends to be the highest in amplitude and the slowest waves. We increase Delta waves in order to decrease our awareness of the physical world. We also access information in our unconscious mind through Delta.

Peak performers decrease Delta waves when high focus and peak performance are required.

However, most individuals diagnosed with Attention Deficit Disorder, naturally increase rather than decrease Delta activity when trying to focus. The inappropriate Delta response often severely restricts the ability to focus and maintain attention. It is as if the brain is locked into a perpetual drowsy state.

Another way to look at Delta is to imagine you are driving in a car and you shift into 1st gear....you're not going to get anywhere very fast. So Delta would represent 1st gear.

Delta (0.1-3 Hz):Distribution: generally broad or diffused may be bilateral, widespread
Subjective feeling states: deep, dreamless sleep, non-REM sleep, trance, unconscious
Associated tasks & behaviors: lethargic, not moving, not attentive
Physiological correlates: not moving, low-level of arousal
Effects of training: can induce drowsiness, trance, deeply relaxed states

By one definition, gamma waves are manifest at 24 Hz and higher, though researchers have recognized that higher level cognitive activities occur when lower frequency gamma waves suddenly double into the 40 Hz range.

Research has shown gamma waves are continuously present during low voltage fast neocortical activity (LVFA), which occurs during the process of awakening and during active rapid eye movement (REM) sleep.

Some researchers do not distinguish gamma waves as a distinct class but include them in beta brain waves.

Gamma waves are involved in higher mental activity and are related with higher reasoning faculties.
Transient periods of synchronized firing over the gamma waveband, of entire banks of neurons from different parts of the brain, have been proposed as a mechanism for bringing a distributed matrix of cognitive processes together to generate a coherent, concerted cognitive act, such as perception.

Gamma waves are associated with solving the binding problem. Recent studies have shown that recognition of new insights occur when patterns jump from 20 to 40 Hz. It is believed by neuroscientists that gamma activity occurs when various chemical messengers foster efficient communications across large swaths of brain tissue.

Although some studies have shown that these frequencies do provide help in treating certain medical conditions, [citation needed] there is not a wide acceptance by the medical community to adopt the practice of brainwave synchronization for emotional/mental disorders. The fixed, constant frequency of the synchronization is less helpful than techniques such as classical neurofeedback or learning meditation, which naturally generate brain wave frequencies that differ from person to person and may vary from minute to minute.

• Neuro Programmer 2 - Software that uses brainwave synchronization for any frequency possible, and can also introduce recorded or typed hypnotic suggestions.
• BWGen - Brainwave entrainment software.
• iMusic - Brainwave entrainment audio.
• Brain Sync - Pioneers in Brainwave Audio Technology
• Centerpointe - Holosync audio.
• LucidQuest - Audio Brainwave Entrainment.
• Sensatio - Software that generates Binaural Beats, used for self-help, producivity and anti-stress.
• S.H.A.R.M. - Self Hypnosis and Relaxation Machine.
• Mind Media Guide - Brainwave Entrainment Software and Equipment
• Interactive Brain Wave Analizer Technologies