How Does Light and Sound Activate Brain Activity?

Our brain is a memory organ that is paced by light and sound. Knowing this allows us to consciously set the stage for increasing our memory, reducing stress, improving sleep and making healthier decisions.

Brainwave entrainment refers to the brain's electrical response to rhythmic waves of sensory stimulation, such as pulses of sound or light. When the brain is given a stimulus, through the ears, eyes or other senses, it emits an electrical charge in response creating a wave pattern.

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 brain waves.

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):

FFR can be useful because brainwaves are very much related to mental state. For example, a four Hz brainwave is associated with sleep, so a four 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.

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.

The brain can be trained by choosing different frequencies of light and sound. In fact, the brain is affected by any kind of rhythmic stimuli. Clicks, drum beats, light flickers, and even physical vibrations or electric pulses have all been proven to effectively entrain the brain. However, to have a significant effect on one's mental state, the stimuli must be configured correctly and precisely timed.

The entrainment of brain waves is very important in establishing healthy rhythms. Making conscious decisions to allow the brain to wake up properly and prepare for rest will make a huge difference in establishing a healthier brain long term. Listening to lower frequency sounds late at night will prepare the body for rest. The antithesis would be to listen the faster upbeat rhythmic music to stimulate more creativity and physical movement during productive time of the day.

Better Brain tip

1)     Wake up each day with meditation to regulate brain wave activity.

2)     Prepare for sleep by reducing light and high intensity sounds ( avoid the news at night)

References:

 Huang, T. L., & Charyton, C. (2008). A comprehensive review of the psychological effects of brainwave entrainment. Altern Ther Health Med, 14(5), 38-50.

Toman J. Flicker potentials and the alpha rhythm in man. J Neurophysiol. 1941;4(1):51-61.

Nyström SH. Effects of photic stimulation on neuronal activity and subjective experience in man. Acta Neurol Scand. 1966;42(5):505-514.

Moruzzi G, Magoun HW. Brain stem reticular formation and activation of the EEG. 1949. J Neuropsychiatry Clin Neurosci. 1995;7(2):251-267.