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by MuLabs – Francisco Marques Teixeira, MSC Neuroscience
Light & Sound Entrainment: The Role of Light and Sound in Our Brain Rhythms: The brain is a complex organ that controls various functions of the human body, including perception, emotion, and cognition. Neuro modulation is the use of different techniques to modify the activity of the brain. Two popular techniques used for neuro modulation are light brain entrainment and binaural beats.
Binaural beats and light entrainment are two popular techniques used to modulate brain activity and promote relaxation, focus, and other cognitive states. While the two methods work through different mechanisms, they share some similarities in terms of their effects on brain activity.


Light entrainment is the process by which external light cues synchronize an organism’s internal circadian rhythms. In humans, the circadian rhythm is a biological process that regulates the sleep-wake cycle, hormone production, body temperature, and many other physiological functions. Light is the most powerful external cue that regulates these rhythms.The process of light entrainment starts when light hits the retina in the eye. The retina contains specialized cells called photoreceptors, which are responsible for detecting light. The most important type of photoreceptor in this process is the melanopsin-containing ganglion cell, which is particularly sensitive to blue light.When light enters the eye, it activates the melanopsin-containing ganglion cells, which send signals to the SCN. The SCN then sends signals to other parts of the brain and body.Light entrainment has many practical applications. It has been used to treat circadian rhythm disorders, such as seasonal affective disorder (SAD), by exposing individuals to bright light therapy in the morning. Light entrainment has also been used to regulate the sleep-wake cycle of astronauts in space and to improve the performance of shift workers.Light brain entrainment is also a technique that uses visual stimulation to synchronize the brainwaves. The brain produces different types of brainwaves, such as alpha, beta, theta, and delta waves, depending on the level of activity. Light brain entrainment aims to induce specific brainwave patterns to enhance the cognitive and emotional states of the individual.One way of inducing light brain entrainment is through the use of a device called a light machine. The light machine produces flickering lights that create a pulsating effect on the brain. This effect causes the brainwaves to synchronize with the frequency of the light pulses. Another method is through the use of colored lights that correspond to specific brainwave patterns.Light brain entrainment has been found to have therapeutic benefits. For example, it can be used to treat depression, anxiety, and sleep disorders. It has also been used to enhance memory, creativity, and focus.Overall, light entrainment is a complex process that involves the interaction between specialized cells in the eye and various areas of the brain and body. By understanding the mechanisms of light entrainment, researchers may be able to develop new interventions to improve sleep, mood, and cognitive function in individuals with disrupted circadian rhythms.


Binaural beats are another technique used for brain neuro modulation. Binaural beats are created by playing two different tones with slightly different frequencies in each ear. The brain perceives a third tone, which is the difference between the two frequencies. This creates a rhythmic pulsation that can synchronize the brainwaves.Binaural beats involve presenting two slightly different auditory tones to each ear, which creates an illusion of a third tone that oscillates at a frequency equal to the difference between the two original tones. For example, if one ear hears a tone at 200 Hz and the other ear hears a tone at 205 Hz, the brain will perceive a binaural beat at a frequency of 5 Hz. This process is thought to stimulate specific brainwave patterns associated with relaxation, meditation, or focus, depending on the frequency of the binaural beat.The effect of binaural beats on the brain depends on the frequency of the tones played. For example, playing binaural beats at a frequency of 10 Hz can induce alpha brainwave patterns associated with relaxation and meditation. Playing binaural beats at a frequency of 40 Hz can induce gamma brainwave patterns associated with heightened focus and cognitive processing.Binaural beats have been used to treat various conditions, such as anxiety, depression, and chronic pain. They have also been used to enhance creativity, focus, and productivity.Research suggests that binaural beats can modulate brain activity in several ways. One theory is that the beats can influence the activity of the brain’s thalamus, a structure that relays sensory information to other areas of the brain. By entraining the thalamus to the frequency of the binaural beat, researchers speculate that this can enhance communication between different regions of the brain, leading to changes in mood, attention, and other cognitive processes.


Electroencephalography (EEG) measures voltage fluctuations resulting from ionic current within the neurons of the brain. Clinically, EEG refers to the recording of the brain’s spontaneous electrical activity over a period of time, as recorded from multiple electrodes placed on the scalp. Diagnostic applications generally focus either on event- related potentials or on the spectral content of EEG. The former investigates potential fluctuations time-locked to an event, such as stimulus onset. The latter analyzes the type of neural oscillations that can be observed in EEG signals in the frequency domain.The electroencephalogram (EEG) measures the electrical activity of the brain, which can be divided into different frequency bands. Theta waves (4-8 Hz) are associated with relaxation, meditation, and creativity, while beta waves (13-30 Hz) are associated with alertness, focus, and concentration.When testing a light entrainment machine, you found increased theta activity when the machine was rotating at 6 Hz and increased beta activity when the machine was rotating at 15 Hz. This is consistent with previous research on the effects of light entrainment on brain activity.At 6 Hz, the machine was likely producing a binaural beat in the theta frequency range, which can entrain the brain to produce more theta activity. This could explain the increase in theta activity observed in your study. Theta activity is associated with relaxation and creativity, which suggests that the machine may have promoted a relaxed and creative state in the participants.At 15 Hz, the machine was likely producing a binaural beat in the beta frequency range, which can entrain the brain to produce more beta activity. This could explain the increase in beta activity observed in your study. Beta activity is associated with alertness and concentration, which suggests that the machine may have promoted a more focused and alert state in the participants.


The purpose of this study is to determine to what extent, if any, the Alphawave Experience influences the cortical brain activity. The testing took place in our Lisbon-based Research Lab, and will involve a sample of 20 participants.This was a one group, single site, observational study. The study implemented an ABC design where all individuals will receive a pre-treatment period of no sound, stable light activity for 5-minutes, as a base-line (A), then a single, 10-minutes Alphawave Experience (Theta Frequency – 6 Hz) and a Alphawave Experience (Beta Frequency – 15 Hz), randomized.The pre-treatment design was to establish a controlled baseline that limits EEG activity with no sound and stable light. Participants seated in a comfortable position within a climate-controlled room. The room consists of no windows, dark, and would mimic a traditional immersive room. Participants used sound/noise canceling headphones that limit external sounds thereby minimizing influence on brain wave activity.


The within-subject design offers us a protocol to assess the difference between pre and during interventions with a small sample of participants. This is an initial study to assess possible influences thereby needing larger samples which could burden additional participants. Moreover, the design offers a cost-efficient means to test its hypothesis before moving towards larger studies.






(i) Decrease in EEG frontal Beta activity
(ii) Increase in EEG frontal Theta/ alpha activity


The study population will include 20 subjects residing in Lisbon, Portugal between the ages of 24-46 years old with a mean age of 34 y.o.
the sample was composed of 12 females and 9 males.


In order to be eligible to participate in this study, an individual must meet all of the following criteria:

1. Provision of signed and dated informed consent form
2. Stated willingness to comply with all study procedures availability for the duration of
the study
3. Males and females; Age 18-65 years.


An individual who meets any of the following criteria were excluded from participation in this study:

1. Current use of medications for following mental health conditions; Generalized Anxiety Disorder, Depression, BiPolar Disorder, Schizophrenia, Attention Deficit Disorder, Panic Attack Disorder, Obsessive Compulsive Disorder. In addition, those with past history of substance abuse disorders.
2. Current use of medications for the following physical health conditions; Hypertension, Arrhythmias, Disorders of the Central Nervous System.
3. Implanted pace parker for cardiovascular conditions
5. Hearing deficits such as deafness or hard of hearing.
6. Females that are knowingly pregnant.


Purposeful sampling was implemented for this study through snowball sampling. Snowball sampling is recruiting through the study coordinator and participants. Participants can help with recruitment of their peers. In addition, recruitment can occur through general contact inviting individuals to participate.There are no vulnerable participants for this study. Safeguards are in place through the inclusion/exclusion screening process to prevent enrollment of vulnerable populations.The study coordinator provided the informed consent and participants will not be compensated for participation.


There is a positive effect on participants cortical regions of the brain related to the frequencies of the AWE:RQ 1: Is there a difference in cortical brain region activity 10-minute AWE and the pre-base-line condition of 5-minutes in a controlled, seated position with no sound & steady light.Repeated Measures ANOVA will be used to assess the possible difference in Pre and During intervention period.


Brain data Softwares

Neuroguide – EEG (Quantitative Electroencephalogram) Data-Base
BBGuide – Mental State EEG correlation software

Please find below a quick summary of the metrics used in this product efficiency study:


Activation/Relaxation is a metric computed by observing the overall activation of the frontal lobe, mainly seeing if there is more or less activation of the Beta (15-30 Hz) on the prefrontal cortex and more activation of the Theta (6-8 hz) frequencies.
The frontal lobe on this range of frequencies is responsible for executive functioning like reasoning, attention, decision making and impulse control. If there is more activation of this area it means that there is more activity on processing and reasoning upon a certain stimuli (internal or external) and the less activity it means there is less attention and reasoning upon a certain stimuli, thus, it means the person is less activated and relaxed.
Relaxation State is a state where your overall activation is down. In common words, it means you are “relaxed”. The nervous system to relax needs to have two main components working “slowly”: the central nervous system and the Autonomic Nervous System.

The central nervous system is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because it integrates the received information and coordinates and influences the activity of all parts of the bodies. The CNS consists of two major structures: the brain and spinal cord. The CNS comprises the Limbic System that supports a variety of functions including emotion, behaviour, long-term memory, and olfaction. Emotional life is largely housed in the limbic system.

The structures and interacting areas of the limbic system are involved in motivation, emotion, learning, and memory. The limbic system operates by influencing the endocrine system and the autonomic nervous system. It is highly interconnected with the nucleus accumbens, which plays a role in sexual arousal and the “high” derived from certain recreational drugs. These responses are heavily modulated by dopaminergic projections from the limbic system. The limbic system is also tightly connected to the prefrontal cortex. Some scientists contend that this connection is related to the pleasure obtained from solving problems. The limbic system interacts heavily with the cerebral cortex. These interactions are closely linked to olfaction, emotions, drives, autonomic regulation, memory, and pathologically to encephalopathy, epilepsy, psychotic symptoms, and cognitive defects. The functional relevance of the limbic system has proven to serve many different functions such as affects/emotions, memory, sensory processing, time perception, attention, consciousness, instincts, autonomic/vegetative control, and actions/motor behavior.

The peripheral nervous system consists of the nerves and ganglia outside the brain and spinal cord. The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body. Unlike the CNS, the PNS is not protected by the vertebral column and skull, or by the blood-brain barrier, which leaves it exposed to toxins and mechanical injuries. The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system.

The somatic Nervous system (SNS) includes the sensory nervous system and the somatosensory system and consists of sensory nerves and somatic nerves, and many nerves that hold both functions.
The autonomic nervous system (ANS) controls involuntary responses to regulate physiological functions. The brain and spinal cord of the central nervous system are connected with organs that have smooth muscle, such as the heart, bladder, and other cardiac, exocrine, and endocrine-related organs, by ganglionic neurons. The most notable physiological effects from the autonomic activity are pupil constriction and dilation, and salivation of saliva. The autonomic nervous system is always activated but is either in the sympathetic or parasympathetic state. Depending on the situation, one state can overshadow the other, resulting in a release of different kinds of neurotransmitters.

The sympathetic system is activated during a “fight or flight” situation in which mental stress or physical danger is encountered. Neurotransmitters such as norepinephrine and epinephrine are released, which increases heart rate and blood flow in certain areas like muscle, while simultaneously decreasing activities of non-critical functions for survival, like digestion. The systems are independent to each other, which allows activation of certain parts of the body, while others remain rested.
The Parasympathetic system allows the body to function in a “rest and digest” state. Consequently, when the parasympathetic system dominates the body, there are increases in salivation and activities in digestion, while heart rate and other sympathetic responses decrease. Unlike the sympathetic system, humans have some voluntary controls in the parasympathetic system. The most prominent examples of this control are urination and defecation.
We can easily access Central Nervous System emotional states using EEG (electroencephalography) technology and compute indirect metrics of the activation deactivation of the Limbic system.


Regarding our results, all the directions of the increase or decrease of a certain frequency were according to our hypothesis:

  • The theta programme increased the Theta frequency in the frontal area and in the posterior area and reduced the Beta frequency in the frontal and posterior area;

  • The Beta programme increased the Beta frequency in the frontal area and in the posterior area and reduced the Theta frequency in the frontal and posterior area;

We noticed that the big differences were in the significance of the results:

  • We had marginal significance in the Beta programme increasing frontal Beta;

  • We had significance in the Beta programme increasing posterior Beta.

These results lead us to believe that the reason for not having significance in all the results is due to the low number of valid subjects in this study.
the really good results in posterior Beta are due to the Beta programme being a really intense programme that activates a lot of the visual cortex, thus the intense visuals the subjects report seeing.


Frontal Theta:
Frontal Theta


Frontal Beta:

Posterior Beta:

BETA Theta


Light brain entrainment and binaural beats are two effective techniques for brain neuro modulation. They work by inducing specific brainwave patterns that can enhance cognitive and emotional states. These techniques have therapeutic benefits and can be used to treat various conditions. However, it is important to note that these techniques should be used under the guidance of a qualified practitioner.While the underlying mechanisms of binaural beats and light entrainment are still being investigated, both techniques have shown promise in modulating brain activity and promoting relaxation, focus, and other cognitive states. As research in this field continues to develop, we may gain a better understanding of how these techniques work and how they can be optimized for specific applications.It’s important to note that the effects of light entrainment on brain activity can vary depending on the individual, the specific frequencies used, and other factors. Nevertheless, your findings are consistent with previous research on the effects of light entrainment on brain activity, and provide further evidence for the potential of this technique to modulate cognitive states.In conclusion, light entrainment is a critical process that helps to regulate our internal circadian rhythms. It is essential for maintaining a healthy sleep-wake cycle and for many other physiological functions. Understanding the mechanisms of light entrainment has practical applications for treating circadian rhythm disorders and improving the quality of life for many individuals.



















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