Down the Rabbit Hole - "Music, the digital drug"

Brace yourselves, because this is going to get deep! I went through a stage of being fascinated with all of this stuff. Over the next few weeks I'll introduce you bit by bit to the incredible world that is the unconcious mind. Specifically, the way that finely tuned sound waves can directly influence our brain state - Scary right? Well, not really... but it's certainly a very interesting idea!

It has been scientifically proven that human brainwave activity can be influenced and artificially guided into altered states using external stimuli such as sound and light. To understand how external stimuli can be used to influence brainwave activity, it is important to understand the principle of resonant entrainment in oscillating systems. Entrainment is a physics term used to describe the process whereby two interacting oscillating systems, which may have their own individual oscillating frequencies when functioning independently, assume the same synchronised frequency. A simple and obvious example of resonant entrainment taking place can be shown using two tuning forks. If a tuning fork designed to produce a frequency of 440 Hz is struck (causing it to oscillate) and then brought into the vicinity of another 440 Hz tuning fork, the second tuning fork will begin to oscillate. The first tuning fork is said to have entrained the second tuning fork and has caused it to resonate. The principles of resonant entrainment also apply to bio-systems. The particular bio-systems of interest here are those related to electromagnetic brainwaves. Brain activity is created by billions of electrochemical impulses that produce electromagnetic waves in the neural system. Brainwaves can therefore be altered chemically with the use of drugs, electromagnetically via induction, or using resonant entrainment of some kind; this study will explore resonant entrainment using audio based stimuli in the form of monaural beats, binaural beats and isochronic tones.

The image bellow shows an audio stimulus and the associated neural response created within the cortex.

This next image shows 2 EEG scans, taken before and after a 6-minute session of 10 Hz monaural entrainment.

Binaural Beats refers to a natural brain response, which is triggered in the Superior Olivary Nucleus of each hemisphere in a human brain. It is observed when a subject is presented with two audio signals of slightly different frequencies, one in each ear. The response is that the subject perceives a third frequency in the form of a series of repeating pulses. The frequency of the perceived pulse is the difference between the two carrier signals (or the rate at which the frequencies move into and out of phase). Although the brain is able to distinguish between left and right audio signals and they are processed as two separate channels, the brain is also able mix the two perceived signals within the Superior Olivary Nuclei. This enables the brain to detect phase between two audio signals without actually sonically mixing the sound waves. It is suggested that binaural beats can be used to entrain brain waves to specific frequencies over a period of time, due to the perceived “beating” that the brain creates within the cortex. Binaural beats are used to produce the sub audible frequency rather than direct audio stimulus of the desired frequency. Although the actual carrier audio signals are not physically mixing together, the brain is still able to detect the phase between the two carrier signals. It is this pulsing frequency perception that is referred to as binaural beats. Many highly evolved species including other mammals and birds are able to detect this kind of phasing in the same way as humans are. The frequency range of detectable phasing from one evolved species to another is dependent on the size of the species’ Cranium (the main part of the skull which encapsulates the brain). In a human, this kind of phasing can be detected when carrier waves are below approximately 1000 Hz (1 kHz) (Oster, 1973). This means that in an average human, the wavelength of a sound wave with frequency of less than 1 kHz is longer than the diameter of the skull and are therefore are able to curve around the skull by diffraction and so, can be heard by both ears. But as it takes longer for the sound to reach one ear than the other, one ear gets a slightly out of phase version of what the other ear gets. This neural mechanism is the result of millions of years of evolution, and it enables us to detect the approximate location of a sound source in three dimensions; particularly those sounds with frequencies bellow about 1 kHz. It is because of the brains ability to locate sounds and to detect movement in sounds using phase difference, that we have the ability to perceive binaural beats. This is the reason why, when creating binaural beats, the carrier frequencies used tend to be bellow about 1 kHz (1000 Hz). When using binaural beats to entrain brainwaves, the frequencies of the carrier signals usually differ by between about 0.5 and 40 Hz (Oster, 1973), as this will result in the production of binaural beats within the frequency range of brainwaves.

Brain waves are divided into 4 types, grouped by their frequency; these are Delta (0.5 - 4 Hz), Theta (4 - 7 Hz), Alpha (8 - 13 Hz) and Beta (13 - 40 Hz).

Delta brain waves are associated with very deep sleep and exploration of the sub-conscious. Delta brainwaves are those with the lowest frequency and greatest amplitude. It is suggested that the ability to synchronise brain wave patterns to Delta frequencies can induce ultra deep sleep and deep hypnosis. When a person’s dominant brainwave frequency is Delta, their body is healing itself. When in a Delta state, dreams do not occur and the subject will be completely unconscious. It is virtually, if not totally impossible to entrain brainwaves to the Delta frequency range. Entrainment into deep Theta states is possible but difficult, but anything lower frequency than this will only really occur naturally.

Theta waves are usually associated with light sleep, dreaming, meditative and ultra relaxed states (Hiew, 1995). Synchronising brain activity with Theta frequencies can help to aid sleep and induce deep relaxation, and are often used in hypnosis and meditation. It is well known that in humans, dreams occur in 90-minute cycles. Towards the end of these cycles, as a person begins to come out of the deep sleep stage, the delta brainwave frequencies increase into the theta range and dreaming begins to occur. As the frequency of the dominant brainwave activity increases even more, a subject will be increasingly aware or conscious of their dreams. Lucid dreaming can also occur at this state and often people are known to have reported very spiritual experiences while in or very near a theta state. Theta entrainment can also be used to achieve accelerated learning and mental programming. These techniques combine a kind of hypnosis with pre-recorded suggestions.

Brainwaves tend to operate at Alpha frequencies when a subject is performing well-practiced tasks, which require little conscious thought or concentration; processes like walking or having a shower, for example. They are dominant when a person is awake and relaxed but not carrying out any intensive neural processes. Alpha brainwaves will also be observed during breaks from active work or thought intensive activities. Alpha brain activity is often associated with creativity and spontaneous ideas. This is why people often have interesting or creative ideas during showers or while doing long motorway drives etc. Waking up in the morning and just before going to sleep, a person will naturally be in the Alpha state. Alpha brainwave activity is automatically increased when a person simply closes their eyes. Entrainment into alpha frequencies is very easy to achieve, and is often used by people who carry out self-hypnosis and mental re-programming to fine tune their brainwave frequency for specific desired states.

During a normal working day, brainwaves within the beta frequency range are the most prominent. Beta waves are observed when the brain is aroused or when a subject is actively engaged in mentally intensive activities. Beta brainwaves are the group with the highest frequency and lowest amplitude. This group also occupies the biggest frequency range out of all four groups and is the most prominent type of brainwave observed in normal, day-to-day life. Beta brainwaves are divided into three subgroups: SMR (Sensorimotor Rhythm) (12 – 15 Hz), Beta 1 (15 – 20) and Beta 2 (20 – 40). SMR relates to physical body motion, so increasing the density of SMR brainwaves can improve the ability to carry out highly physical tasks and co-ordinate complicated physical manoeuvres such as gymnastics moves or dancing. Entraining to Beta 1 can help to improve focus and increase IQ as well as generally improving the ability to carry out mentally intensive tasks. Entraining to this sub-band has even been proven to temporarily increase IQ by an average of 6 points. Beta 2 relates to highly alert and anxious states, high beta states will be observed during a heated confrontation between two people or a fight, or when a person is fearful or nervous. The ability to entrain brainwaves to SMR beta and beta 1 states can used as a very important treatment for people with various mental or emotional disorders like ADD, depression or insomnia.

A person’s state of mind is determined by the dominant brainwave frequency, even though other brainwave frequencies may be present. For example, if Alpha brainwaves are dominant then a person will be in an Alpha state. A persons dominant brainwave frequency can be seen using EEG (Electroencephalography) technology, which involves scanning the electrical current present in the brain using electrodes positioned on the scalp.

The image bellow shows an EEG analysis with dominant brainwaves in the alpha range, around 10 Hz, and so this person will be in an alpha state. Brainwaves of all frequencies are present but they vary in density and amplitude.

The first documented mention of entrainment dates back to around 100 A.D by a Greek mathematician, geographer, astronomer and astrologer known as Ptolemy. Ptolemy is known as the first scientist to have come across entrainment in the form of photic (light) stimulation. He noticed that when starring through a spinning, spoked wheel, the spokes appeared to stop moving when the wheel’s revolutions reached a certain speed. In 1899, a French physician by the name of Pierre Marie Félix Janet resurrected Ptolemy’s ideas from almost 2000 years prior, and demonstrated brainwave entrainment by exposing his patients to a flickering light created by a rotating strobe-wheel, lit by a lantern positioned behind it. The patients experienced increased relaxation and reduced hysteria. This was the first time that entrainment had been used clinically as a treatment.

Although it’s effects had been recognised for hundreds of years, and it had been used medically since 1899, brainwave entrainment was not officially identified and explained scientifically until 1934 by Researchers, E. Adrian and B. Matthews.  In 1929, just after Hans Berger discovered Alpha brainwaves, scientists observed that brainwaves could be increased way beyond their natural frequency using flickering lights to entrain them. They called this effect "Photic Driving". This is another name for brainwave entrainment by means of light stimulation.

In 1942 Dempsey and Morison discovered that repetitive tactile stimulation could also produce entrainment and in 1959, Dr. Chatrian observed auditory entrainment in response to clicks at a frequency of 15 per second. This was the first time that audio had been used to entrain brainwaves. This technique, using one mono sound comprised of individual impulses or amplitude modulation cycles, is now known as isochronic tones entrainment, or monaural entrainment. Monaural is the opposite of binaural in that the audio pulses are actually created sonically, rather than neurologically, within the cortex. This means that headphones are not required when presenting a subject with monaural entrainment audio. In order for isochronic tones to have a significant effect, monaural entrainment audio must be presented at a loud enough volume that the listener is able to hear a noticeable modulation in tones.

“Because many of our entrainment methods do not rely on speaker assignments, you can use Mind Stereo without headphones and retain the full effect.” – (Mind Stereo Features page, http://www.transparentcorp.com/products/mindstereo/features.php)

Prussian physicist and meteorologist, Heinrich Wilhelm Dove, first discovered binaural beats in 1839. But the idea of using them to entrain brainwaves did not surface until the publishing of a magazine article in the Scientific American entitled "Auditory Beats in the Brain", by Gerald Oster, in 1973. This article pieced together relevant research form the past 134 years on binaural beats since Dove’s discovery, as well as bringing new and innovative research and laboratory findings into the spotlight. Oster is credited as being the first person to suggest that binaural beats can be a powerful tool in cognitive therapy and neurological research. He also addressed the questions encompassing the ability of many animals, including humans, to locate sounds in three dimensions and it was him who discovered that we have developed an evolutionary mechanism that enables us to detect phase between two separate audio signals and that it is this mechanism that is also responsible for our ability to detect binaural beats.

In 1981, Arturo Manns et. al. published a study whereby patients experiencing, facial or jaw pains (TMJ dysfunction) and related insomnia problems, were treated with monaural, isochronic tones.

“The subjects were given isochronic tones for 15 minutes, followed by 15 minutes of EMG biofeedback (sounds of muscle electrical discharge) on masseter muscle tension, then isochronic tones combined with the biofeedback. When the subjects used isochronic tone stimulation, they experienced deeper muscular relaxation than when they practised relaxation with biofeedback. The simultaneous use of both biofeedback and isochronic tones produced the deepest relaxation. There was an overall improvement in their mandibular movements. Facial pain, insomnia and emotional tension were reduced considerably.” - (The Rediscovery of Audio-Visual Entrainment. D. Siever, C.E.T. 1997.)

A little later, in 1999, Thomas H Budzynski, PhD, carried out a study examining the effects of audio-visual brainwave stimulation on eight college students with learning difficulties. The students who received brainwave stimulation outperformed a control group of similar abilities and showed a significant increase in their grade point average. Multiple similar studies have backed up these results and it seems that entraining to beta 1 frequencies is remarkably effective. One such study, carried out by Psychologist Michael Joyce, examined the use of brainwave entrainment on a group of 30 child subjects. He found substantial improvements in attention and reaction and a reduction in impulsivity and variability after only a short period of treatment. He also observed improvements in reading and a half a year advancement in grade level. Furthermore, Harold Russel, PhD, and John Carter, PhD, two professors at the University of Houston, carried out several studies involving subjects with ADD and other learning disorders. They used brainwave entrainment to treat the subjects, and the follow-up tests showed a consistent 5 to 7 point increase in IQ when comparing the results from before and after the treatment.

In recent years, brainwave entrainment technology has become very advanced. A range of software programs is available, from affordable, easy to use, personal synthesisers to much more advanced, expensive and professional utilities combining audio and visual stimuli and offering incredibly precise control. Also, personal EEG machines are now available and are even reasonably affordable. They range from around £500 to several thousand pounds. Modern software also often has built in EEG compatibility allowing users to monitor their brain activity, develop their own personal entrainment programs and even learn to control their state of mind using biofeedback.

Infact, I have created my own basic binaural beats synthesiser using the audio based programming application Max / MSP. It is a very simple design and uses not much more than two sine wave oscillators, a noise oscillator and an integrated sample player. See the picture bellow if you're interested!

My patch allows the user to control the carrier frequency and the beat frequency over time. The carrier frequency can be controlled via midi by an external sequencer or controller, allowing the user to tune the synth to a piece of background music, which will help to hide the binaural tones, which can sound unpleasant otherwise. The synth also allows the user to mix between monaural and binaural beats, automate the beat frequency over time in order to create personal entrainment routines, add white noise or custom audio loops to mask the binaural beats, and also includes a mixer to control the volume of the beats, noise and the sample player. There is also a preset box containing different graph shapes and upper / lower boundaries for the graph; so essentially, a set of preset entrainment routines to choose from. This patch is sufficient for creating effective binaural beats and is perfectly capable of entraining brainwaves to a certain extent, however it is also fairly limiting, mainly due to the fact that it does incorporate any other entrainment techniques, such as photic driving (entrainment using light stimulation).

There are many other pieces of software available on the market which will allow you to create your own brainwave entrainment media. Here are some details on a few of them:

Mind Stereo

This is a piece of software aimed at people with limited knowledge of brainwave entrainment and a tight budget. It is available for a roughly £20 and instead of using purely binaural beats, it is also able to use audio processing techniques such as precise amplitude modulation to create entraining beats out of any audio file loaded into it. It can be used as an ordinary audio player to play any music or sound file and is very user friendly and easy to use. It also combines the use of ordinary, waveform based visualisations with strobe effects that flash in sync with the audio beat frequency. This offers a rich visual stimulus and is a perfect accompaniment to the audio based entraining beats. The program comes with preset sessions designed for different purposes as well as a simple but sufficient editor to create and customise personal entrainment routines. Mind Stereo uses both monaural and binaural audio entrainment, which means that many of the sessions can be used without headphones.

Here are some screenshots of Mind Stereo:

Mind Workstation

A more expensive piece of software designed to create brain-stimulating audio and video is “Mind Workstation”. This software allows the user to create full and intricate brain stimulation sequences using a number of different techniques, and also incorporates biofeedback capabilities. Biofeedback is a practice, which involves learning to recognise and respond to signals from ones own body. It can be as simple as taking a temperature reading to check for illness, and responding appropriately. But in the context of brainwave entrainment it involves using EEG readings from the user’s brain to produce audio and video signals, which the subject monitors live. This creates a feedback loop where the actual brainwaves being produced are the basis for the new entrainment media, which is presented to the user and processed by the brain, magnifying the effects of brainwave entrainment substantially. It enables extremely precise neural programming and brainwave synchronisation. Mind Workstation also comes with a selection of biofeedback “games” which are designed to train the user to control their state of mind. These games, which are based on visualisations, respond to the biofeedback information fed into them and the user’s objective is to control the visualisations by modifying their brain state.

Here are some screenshots:

Brainwave entrainment is a powerful tool, which can be used to guide the human brain into altered states of mind, some of which may render the subject more venerable than others. It can also make people more open to hypnotic and subliminal suggestion, which presents moral dilemmas when considering the use of entrainment or other mind altering techniques commercially, in music for example. Entrainment has however been used in commercial audio CDs designed specifically to induce certain states of mind, most of which contain disclaimers that warn the listener of the mind altering affects. For example, it is usually suggested that people who suffer from epilepsy avoid entraining media, as the frequencies involved are similar to those that can trigger epileptic fits. Also pregnant women are advised to avoid entrainment media and driving while listening to certain entrainment frequencies (those bellow high alpha frequencies) is strongly discouraged.

“Those who should not use this application include: Those who are prone to or have had seizures, are photosensitive, epileptic, pregnant or wear a pacemaker, whether knowingly or not, should not use this application. Children under the age of 18 are to be examined by a physician for epilepsy or illnesses that may contribute to seizures prior to the use of Mind Stereo, as they are more susceptible to seizures. Finally, DO NOT USE MIND STEREO WHILE DRIVING OR OPERATING MACHINERY.” 

-       (Mind Stereo disclaimer - http://www.transparentcorp.com/)

However, although it may be difficult to implement some kind of preset entrainment techniques in commercial music, there is a huge amount of scope for  using it in customisable personal media players. Combining brainwave biofeedback with neural brainwave programming is already being used as an effective alternative to anti-depressants and other medical drugs, to a certain extent, and it seems likely that in the not too distant future, EEG machines and biofeedback mechanisms could become so affordable, discrete, easy to produce and accurate, that they could be implemented into personal music players, which could then select, alter or even produce personalised music or audio based on preset sessions similar to those included in Mind Stereo. Brainwave entrainment with biofeedback could easily become a new dimension in music, particularly if implemented in personal music players, in that they would allow the user to customise the music that they listen to by programming it to make them feel a certain way. Specific frequencies are known to have specific effects on the brain. For example, simply entraining the brain to specific frequency combinations, and using carrier tones of specific frequencies can trigger the release of serotonin, endorphins, growth hormones, adrenaline and even testosterone. These specific frequencies are very difficult to find publicly as they are worth a lot of money to researchers and developers for obvious reasons!

“The application of technology as an aid for the many people not trained in meditative traditions is an exciting area of inquiry… Daily use of this technology for mind/body integration and stress reduction has proven to be very beneficial.” - (Audio Anecdotes: Tools, Tips, and Techniques for Digital Audio - Ken Greenebaum, Ronen Barzel. A.K Peters Ltd, 2004)

Brainwave entrainment technology is quickly developing and it could well have a huge roll in the evolution of music and certainly on alternative medical treatments. Music and sound therapy has never before been such a powerful tool for treating mental conditions such as depression, insomnia ADD and stress, and is proving to be a powerful alternative to drugs. It has an extremely wide range of possible applications both as a personal aid to meditation, creativity or self-motivation, but also as a powerful and versatile treatment in the medical field.

If you're still reading... Congratulations, that's all for today! In the next couple of weeks I'll be sharing my own brainwave entrainment project which includes several piece of music designed to invoke different moods and brain states. So keep your eyes peeled. This article was written by me (adapted from an essay which I wrote a couple of years ago). I hope you learned something from it and it and didn't find it too boring!

More soon!