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Stimulating the Brain with Light & Sound

What are Brainwaves? | Stimulating the Brain | Technical Info | A Brief History

The Neuro-Programmer uses sound and light to directly affect the brain through a complex neural process called Brainwave Entrainment.

What is Brainwave Entrainment?

Brainwave Entrainment (pronounced: "ehn - TRAIN - mint") refers to the brain's electrical response to rhythmic sensory stimulation, such as pulses of sound or light. 1 2 3 4 5

When the brain is given a stimulus, through the ears, eyes or other senses, it emits an electrical charge in response, called a Cortical Evoked Response (shown below). These electrical responses travel throughout the brain to become what you "see and hear." This activity can be measured using sensitive electrodes attached to the scalp.

When the brain is presented with a rhythmic stimulus, such as a drum beat for example, the rhythm is reproduced in the brain in the form of these electrical impulses. If the rhythm becomes fast and consistent enough, it can start to resemble the natural internal rhythms of the brain, called brainwaves. When this happens, the brain responds by synchronizing its own electric cycles to the same rhythm. This is commonly called the Frequency Following Response (or FFR):

Brainwave Entrainment In Action!

FFR can be useful because brainwaves are very much related to mental state. For example, a 4 Hz brainwave is associated with sleep, so a 4 Hz sound pattern would help reproduce the sleep state in your brain. The same concept can be applied to many other mental states, including concentration, relaxation and meditation.6 7 8

If you listen closely during an NP3 session, you will hear small, rapid pulses of sound. As the session progresses, the frequency rate of these pulses is changed slowly, thereby changing your brainwave patterns and guiding your mind to various useful mental states.

What is Entrainment?

Entrainment is a principle of physics. It is defined as the synchronization of two or more rhythmic cycles. The principles of entrainment appear in chemistry, neurology, biology, pharmacology, medicine, astronomy and more.

CASE IN POINT: While working on the design of the pendulum clock in 1656, Dutch scientist Christian Huygens found that if he placed two unsynchronized clocks side by side on a wall, they would slowly synchronize to each other. In fact, the synchronization was so precise not even mechanical intervention could calibrate them more accurately.

More Information:

> A short history of brainwave entrainment

> Technical information on brainwave entrainment

> Binaural beats

> Isochronic tones and Neuro-Programmer 3

> Research and further reading section

> Frequently Asked Questions (FAQ)



Next: Technical Section - Advanced information on brainwave entrainment



1. Huang, T. L., & Charyton, C. (2008). A comprehensive review of the psychological effects of brainwave entrainment. Altern Ther Health Med, 14(5), 38-50.
2. Toman J. Flicker potentials and the alpha rhythm in man. J Neurophysiol. 1941;4(1):51-61.
3. Nyström SH. Effects of photic stimulation on neuronal activity and subjective experience in man. Acta Neurol Scand. 1966;42(5):505-514.
4. Moruzzi G, Magoun HW. Brain stem reticular formation and activation of the EEG. 1949. J Neuropsychiatry Clin Neurosci. 1995;7(2):251-267.
5. Rogers LJ, Walter DO. Methods for finding single generators, with application to auditory driving of the human EEG by complex stimuli. J Neurosci Methods. 1981;4(3):257-265.
6. Patrick GJ. Improved neuronal regulation in ADHD: An application of 15 sessions of photic-driven EEG neurotherapy. J Neurother. 1996;1(4):27-36.
7. Ossebaard HC. Stress reduction by technology? An experimental study into the effects of brainmachines on burnout and state anxiety. Appl Psychophysiol Biofeedback. 2000;25(2):93-101.
8. Cahn BR, Polich J. Meditation states and traits: EEG, ERP, and neuroimaging studies. Psychol Bull. 2006 Mar;132(2):180-211.