Archive for 'Studies and Research'

New Study Points to Significant Relationship Between Brainwave Entrainment and Heart Rate Variability

Over the past year, Dr. Elio Conte and a team of researchers from the University of Bari in Italy have been conducting a study using Neuro-Programmer 3. Their work ultimately led to the finding of a statistically significant relationship between alpha brain wave entrainment and enhanced heart rate variability. In September 2013, their work was accepted after peer review, and published in the World Journal of Neuroscience. Because of the tremendous importance of HRV, and the scarcity of known HRV interventions, this research is incredibly exciting.

The study focused on ten subjects, 4 males and 6 females, 28 – 62 years old, ascertained to be in healthy condition. For each subject, the research team first took HRV measurements during 5 minutes at rest, in complete quiet and with the patient in a comfortable position. Then, each subject listened to 20 minutes of alpha stimulation (at 8 – 10 Hz), generated by Neuro-Programmer 3.

The research team then compared the average total HRV experienced by subjects during the at rest state to that experienced during the alpha stimulation, and noted an increase for each subject in total variability, ranging from a 20% to a 68% improvement.

We’ve created a new page on our site to better explain the importance of HRV, and why this research could be so significant. We link to the full text of the study from that page as well. You can find all of that information at this link:

Research in focus: “Alpha-rhythm stimulation using brain entrainment enhances heart rate variability in subjects with reduced HRV”

Binaural Beats Reduce Patient Anxiety During Cataract Surgery

Researchers at Chiang Mai University in Thailand, led by Dr. Pornpattana Vichitvejpaisal, M.D., have found that patients listening to binaural beats during surgery experienced lower heart rates and decreased anxiety throughout the procedure. Cataract surgery is one of the most commonly required surgical procedures in the USA, and it is often performed with only local anesthesia, meaning the patient is awake while the surgery is being conducted. That last fact makes it quite clear why anxiety can be an issue for many of the patients who undergo this procedure.

The findings were presented this month at the annual meeting of the American Academy of Ophthalmology. I had the chance to discuss this study with the lead researcher, Dr. Vichitvejpaisal, who generously offered his time to answer a few questions and provide additional details about the use of binaural beats in this experiment.

Here’s what Dr. Vichitvejpaisal had to say about the protocol and session configuration used for this study:

“We created binaural beats with a frequency of 20 Hz (EEG: beta wave, for normal activity or anxiety) in the first 5 minutes.

The binaural beat frequency was set to decline gradually to the therapeutic frequency of 10 Hz (EEG: alpha wave, for relaxation) within the following 5 minutes and be sustained for the remaining 50 minutes to ensure enough operative time.

Musical arrangements with relaxing components of melodies, tones and rhythms with a 60-minute duration were embedded with the binaural beats. Natural sounds such as waterfalls, birds, ocean, river and forest sounds were also inserted.”

The study included 141 people, who were split up into groups of 47 each. One group listened to the binaural beats combined with music and nature sounds, the second group listened only to the music with the natural noises, and the third group didn’t listen to anything at all.

The result of the experiment was that the binaural beats group experienced significant reductions in heart rate, systolic blood pressure and anxiety, compared to the control group that did not listen to anything. The patient’s anxiety was measured by the STAI (State Trait Anxiety Inventory), which is a standard and widely used test in the field.

To the team here at Transparent, one of the most exciting aspects of this research is the use of a control group listening to only music, without the binaural beats. Other significant studies have used this control method as well, and it’s a great test to further validate the brainwave entrainment effect as being separate from the neurological results of simply listening to relaxing music.

Those in the group receiving binaural beat stimulation showed the largest reduction in heart rate and anxiety levels, compared to both the control group and the group who listened to music without binaural beats.

Dr. Vichitvejpaisal does have goals to complete even more research in this area, he explained, “we plan to conduct this research on more operative surgery that causes anxiety, or long time operative surgery, to evaluate more effects of the binaural beat.”

That’s good news for the entire field, and we’re looking forward to the results of any future research ventures from this team.

Medical Xpress reported this anecdote about the experience of one patient during the study:

“Dr. Vichitvejpaisal referenced one of his study participants who reported that during her first cataract surgery, she was afraid from the moment she entered the surgical suite. Though she’d been told it wouldn’t take long, the surgery seemed to drag on endlessly. Receiving sound therapy during her second surgery dramatically changed her experience from start to finish. She said that she felt very little anxiety, and that the surgery was over before she knew it.”

If you’d like to try a binaural beat/brainwave entrainment session, Neuro-Programmer 3 is a great place to start.

How Your Brain is Like a City

Image credit: Van Wedeen, M.D., Martinos Center and Dept. of Radiology, Massachusetts General Hospital and Harvard University Medical School

The link between the two isn’t metaphorical in this case- according to a new study, the connective foundations of our brain look as though they were designed by a grid-focused city planner.

Researchers used cutting-edge imaging technology to look at places where the fibers that carry messages from one part of the brain to another intersect. And they found a remarkably organized three-dimensional grid, according to Van Wedeen of Harvard Medical School, the study’s lead author.

The grid is a bit like Manhattan, Wedeen says, “with streets running in two dimensions and then the elevators in the buildings in the third dimension.”

Obviously this brain-city would not fit on a single plane- the human brain has many folds and curves. So, Wedeen says, “you have to imagine Manhattan bent into some odd shapes. But the underlying grid doesn’t change. The streets intersect at 90-degree angles and the buildings rise vertically.”

It sounds to me like that brain is less like Manhattan, and more like the city pictured during this famous scene from Inception:


This city-like grid represents a significant shift from the traditional model of the brain’s wiring. Wedeen explains that in the old view, “the brain looked somewhat like a plate of spaghetti or perhaps like one of those old antique telephone switchboards with a million wires running more or less at random.”

This new model for understanding the internal structure of the brain may help to explain how a relatively small number of genes contain the blueprint for something as complex as the human brain- a question that has stumped geneticists for years.

The answer may be that in a highly organized grid system with consistent rules, a genetic blueprint doesn’t have to describe every detail of the final product, Wedeen says. “The grid system would allow a species to gradually add new functions to its brain much the way an architect adds extra floors to a building or a city planner adds new streets.”

There remains some uncertainty regarding whether the entire brain is actually laid out in this way. Weeden was only able to resolve the grid for about a quarter of the human brain, mostly in the deepest parts. Some researchers have expressed the opinion that their model is oversimplified, or that while the grid may exist, it is combined with other, crisscrossing connections as well.

The debate may be resolved within 5 years- that is the timetable for the US National Institute of Health’s Human Connectome Project, which aims to map all the brain’s wiring and demonstrate its connection to mental health over the next half-decade.

Sources:  Research abstract: “The Geometric Structure of the Brain Fiber Pathways” – Science Magazine

Press release: “Brain Wiring a No-Brainer?” 

The Human Connectome Project

Theta Wave Activity Linked to Improved Memory Recall

If you think about it, you probably feel as though you have both good and bad memory days- maybe even hours. I like to think that my memory is pretty strong as a general rule, but there are periods of time where I’m just drawing blanks. There’s a whole host of reasons for these variations. After all, it’s not as though every person is born with a “memory score” that permenantly determines their ability to recall information. Like everything related to our minds, it’s far more intricate than that.

New findings from a prestigious center of neuroscience are demonstrating the significant relationship between levels of theta brain wave activity and our ability to remember at that moment in time. A paper describing this work, from scientists at UC Davis, was recently published in the journal Proceedings of the National Academy of Sciences.

To prove their case, professors and graduate students measured theta wave oscillations in the brains of volunteers during a memory test. Volunteers were asked to memorize a series of words. They later had to recall whether they had seen the word previously, and the context in which the word was seen. Volunteers who were experiencing higher levels of theta wave activity right before they were asked to remember an item were more likely to remember correctly.

Memory recall improved only when volunteers had high theta activity before they heard the cues. If it had been the case that theta activity had increased only after the cues were given, this study would instead suggest that theta waves were stimulated by the cues themselves—perhaps an indicator that the brain was processing a new challenge. But that was not the outcome here. Subjects whose brains were in a high-theta state were essentially “primed” to do better on the memory test once it started.

Of course, this should not be taken to mean that high levels of theta activity are the only factor behind successful memory recollection, but the study does lend support to the idea that everyday memory ability is just as much as a reflection of what’s going on inside the mind as the context outside of it.

“The work goes against the assumption that the brain is waiting to react to the external world. In fact, most of the brain is busy with internal activity that is not related to the outside world — and when external stimuli come in, they interact with these spontaneous patterns of activity.”

– Charan Ranganath, Professor, UC Davis Center for Neuroscience

In this study, the researchers did not actually attempt to stimulate theta activity- they were merely measuring it and recording results. Their hope is that research could lead to treatments for memory loss. Ideally, audio visual stimulation methods to increase theta activity will be part of the dialogue as this research moves forward.

Source: University of California

Emotion revealing itself to researchers…

This abstract points to a great example of the work being done to verify what AVS/Entrainment enthusiasts already know – that emotions, brain rhythms and audio-visual stimulation are usefully inter-related.

When looking for answers that apply to people in general, statistical science has a lot to offer – it’s nice knowing that what you think is happening with your sessions has a sound underlying mechanism. On the other hand, once you become familiar with your own personal responses, emotion/stimulus correspondences much better than “the average recognition rate of 56.66% and 66.67%” can be routinely achieved, i.e. knowing what your own EEG typically looks like, you will be able to tell a lot more about yourself than you could with a “blind” EEG, and you will quickly be able to predict your own response to a particular stimulus.

Abstracts like this are a goldmine for session developers – tantalising snippets just begging to be incorporated into AVS sessions.

With such safety and simplicity, it’s easy to underestimate what can be achieved with sound and light.


Neuroplastic changes found following brainwave training

A user just sent me a link to an exciting new study outlined in Science Daily about brainwave training resulting in changes in brain plasticity (or the ability of the brain to adapt to change):

Significant changes in brain plasticity have been observed following alpha brainwave training.

A pioneering collaboration between two laboratories from the University of London has provided the first evidence of neuroplastic changes occurring directly after natural brainwave training. Researchers from Goldsmiths and the Institute of Neurology have demonstrated that half an hour of voluntary control of brain rhythms is sufficient to induce a lasting shift in cortical excitability and intracortical function.

40 Hz and Consciousness

A new study looks at the significance of gamma waves in consciousness. Gamma has for some time been suspected as being an important band for self-awareness and other aspects of consciousness – 40 hz in particular. This study refines that thought.

Here’s the abstract:

What makes us become aware? A popular hypothesis is that if cortical neurons fire in synchrony at a certain frequency band (gamma), we become aware of what they are representing.

…we also observed increases in gamma band ERS within the amygdala, visual, prefrontal, parietal, and posterior cingulate cortices to emotional relative to neutral stimuli, irrespective of their availability to conscious access. This suggests that increased gamma band ERS is related to, but not sufficient for, consciousness.

What Gamma Can Do For You

For a long time neuroscientists have shown work from poor unsuspecting birds and cats that there are specific critical periods in development important for a functional visual system or a species-appropriate bird song. In humans there have been a few unfortunate cases of horrific neglect of children (i.e. Genie) that have likely been responsible for profound intellectual deficits, which have been informative to scientists interested in the consequences of depravation during the early years. But scientists have not been able to conduct a formal and yet ethical scientific experiment to measure the relationship between a critical period and its function in humans until now, thanks to the ability to measure gamma.

On Oct 21st, the Science Daily featured an article on the exploration of the critical period for language development and other skills in toddlers by measuring their gamma waves on the EEG. The time period between 16 to 36 months is a time of tremendous language growth in humans, where their vocabulary typically expands from about 100 to 1000 words. Dr. April Benasich from Rutgers University in Newark, measured gamma activity in the frontal cortex of toddlers (16, 24 and 36 months) while they sat on a parent’s lap and quietly played. Gamma power (which is determined by the amount of synchronous gamma firing) was associated with language development, cognitive skills, behavior and impulse control. The more advanced a child’s language or cognitive skills, the more gamma power that child showed. And as expected, children who’s parents had a history of language impairments showed lower gamma power.

This new finding is consistent with what is already known about gamma in adults and from work in animals. Gamma heightens during the processing of linguistic information, during the formation of ideas and memories and during other abilities. Furthermore, gamma fires between 2 regions of the brain during associative learning, when a new concept is linked to one already known.

Low gamma coherence within different hemispheres is associated with ADD and learning disabilities. In fact Dr. C. Njiokiktjien from the Amsterdam, Netherlands compared intrahemispheric coherences of various frequencies (including gamma) of children with non-verbal vs. verbal learning disabilities(1). Their results suggested that children with non-verbal learning disabilities had less connectivity in the right hemisphere, which is consistent with the idea that it’s the right hemisphere that manages spatial skills, as well as other non-verbal tasks.

Dr. Hermann from Magdeburg University in Germany presents a model of gamma based on its power under various psychiatric conditions(2). Too much gamma firing is associated with ADHD, positive associations in Schizophrenia (i.e. hallucinations) and epilepsy, and Alzheimer’s disease, negative symptoms of Schizophrenia (i.e. blunt or flat affects) are associated with too little gamma.

So can we benefit from using brainwave entrainment to help us enter gamma states? Or are there risks associated with having more gamma power?

Dr. R. Olmstead, a clinical psychologist from Sunrise, FL, found benefits with gamma training in children with non-verbal learning disabilities, ages 6-16(3). She exposed them to 35 min brainwave entrainment sessions twice a week for 6 weeks. The sessions alternated between excitatory sessions (increasing from 14 (beta) to 40 (gamma) Hz), and inhibitory sessions (decreasing from 40 to 14 Hz). She found that her training enhanced various non-verbal cognitive abilities such as processing speed, freedom from distractibility, arithmetic and coding.

But what about the rest of us?

I think there is good reason to hypothesize that gamma training might also benefit many with other learning disabilities as well. But I am concerned about the fact that ADHD is associated with too much gamma firing. Thus if you have a learning disability and ADHD, or just ADHD alone, or even if you didn’t have any signs of ADHD, would gamma training enhance your distractibility or impulsiveness? 

Unfortunately, there hasn’t been enough research done to answer these questions at this point. However, there is good news. Brainwave entrainment for most of the population is a very gentle stimulus, and it takes time for cognitive benefits to take effect. Thus training with gamma (or any other stimulus) is done slowly. All such training should be conducted mindfully, and if you start to develop any unwanted symptoms, you can simply stop your training, and the effects will likely to go away. The higher the gamma power, the more severe the symptoms, so ignoring milder unwanted side effects could be dangerous.

The study by Olmstead might also be a good example as to how to safely train gamma. She trained students to progress into gamma with the excitatory protocol, and to leave gamma and return to beta in the inhibitory protocol. I would imagine that such training is good for leading our brains in and out of gamma as needed. And thus it might be teaching our brains to self regulate.

Nevertheless, there is an element of adventure in using gamma to potentially enhance your cognitive skills, and if the idea makes you queasy, I’d stand back and wait for more research to be done.

1 Njiokiktjien C, de Rijke W, Jonkman EJ. Children with non-verbal learning disabilities (NLD): coherence values in the resting state may reflect hypofunctional long distance connections in the right hemisphere. Fiziologiia cheloveka. 2001; 27: 17-22.
2 Herrmann CS, Demiralp T. Human EEG gamma oscillations in neuropsychiatric disorders. Clin Neurophysiol. 2005; 116: 2719-33.
3 Olmstead R. Use of Auditory and Visual Stimulation to Improve Cognitive Abilities in Learning-Disabled Children. Journal of Neurotherapy. 2005; 9: 49-61.

New study on Brainwave Entrainment (By Dr. Huang)

I’m pleased to announce the publication of “A Comprehensive Review of the Psychological Effects of Brainwave Entrainment” in Alternative Therapies in Health and Medicine this month. This paper is the most comprehensive review of peer reviewed research in the subject, and was written in order to inform those within and the beyond the field of brainwave entrainment (BWE), and to provide sufficient background for future research.

Most of the research known to date has been summarized by David Siever in two unpublished manuscripts that he sells and distributes. They contain much valuable information about the history of BWE, both published and unpublished studies and proposed mechanisms of action. However, despite their length, they do not provide a complete listing of the peer reviewed literature, nor have his manuscripts faced the scientific scrutiny that comes with publishing in a peer reviewed journal. In fact, in our comprehensive search, we found articles that have never before been mentioned by those in the brainwave entrainment development and scientific community. Why? Believe it or not, the problem is in the inconsistency in terminology used to describe BWE. The term, BWE, until today, cannot be found in the scientific literature. Instead it is referred to as audiovisual stimulation, photic stimulation, photic driving, auditory entrainment, etc, etc. In all I did a search using 31 different terms to look for articles on brainwave entrainment, which returned 27,830 articles using Ovid (1 out of the 4 databases I used to do the search). Only a very small handful of these turned out to be articles on BWE. Thus much of the credit needs to go to my bosses at Transparent Corporation, who gave me the time to do this exhaustive, time consuming, and yet important work.

I looked for papers with psychological terms that described outcomes that I’d seen associated with BWE on the web, in conferences and in the published and unpublished literature. After combining the two searches, and screening for those that were indeed articles addressing psychological outcomes of BWE, and those that passed some basic scientific criteria, we ended up with just 20 articles.

The psychological effects that had been examined in relation to BWE included cognitive functioning (we divided it into verbal, non-verbal, memory, attention and overall intelligence), stress (long and short-term), pain, headache/migraines, mood, behavior and pre-menstrual syndrome (PMS). When two or more studies had examined similar outcomes, we placed them into tables for greater comparability. Thus we had five tables divided by cognitive functioning, stress, pain, headaches/migraines and mood. Studies used a variety of different frequency protocols and stimulation methods which are outlined in the tables.

Out of the 20 studies, 17 were actually developed to support or confirm a hypothesis, and of these, all found a positive effect in at least one outcome. And in each outcome mentioned, at least one study had a positive finding. What was remarkable was that for some outcomes, only one of several protocols had a positive effect, while others were improved by a variety of different protocols. The most consistent positive findings were found in attention (4/4 studies), pain (3/3 studies) and headache/migraines (3/3). While positive effects were found in all other outcomes examined except for mood, either fewer studies had been conducted or a smaller percentage of the protocols examined were effective. Mood was examined in the 3 studies where the effects of theta were examined on a variety of outcomes. So we believe that the ability of brainwave entrainment to positively effect mood has not been properly tested in the peer reviewed literature.

Overall, we conclude that brainwave entrainment shows real potential to positively affect psychological outcomes. However, more and bigger studies need to be done, using additional outcomes and outcomes already examined. We hope that we’ve provided the necessary background to inspire future research and collaboration, so that the field of brainwave entrainment can gain recognition and momentum in the scientific literature.

To view a copy of this article, visit:

Tina L. Huang, Ph.D.
Director of Research
Transparent Corporation

Anger, stress and healing time

The last few weeks have been taken up by my favorite part of this job: testing new equipment. I’ve been working on making the BioScan and EMWave (HeartMath) devices compatible with our Mind WorkStation software. We also received the latest LightStone hardware from Wild Divine. So, I’ve been able to spend a lot of time lately in stress-free biofeedback bliss.

But some of my fellow Columbus residents haven’t been so lucky.

In a recent study by Jean-Philippe Gouina, at our own Ohio State University, 98 Columbus residents valiantly lent their forearms to the cause of science, in order to confirm that high anger levels will likely increase the time it takes to heal:

A sample of 98 community-dwelling participants received standardized blister wounds on their non-dominant forearm. After blistering, the wounds were monitored daily for 8 days to assess speed of repair.

Individuals exhibiting lower levels of anger control were more likely to be categorized as slow healers. The anger control variable predicted wound repair over and above differences in hostility, negative affectivity, social support, and health behaviors. Furthermore, participants with lower levels of anger control exhibited higher cortisol reactivity during the blistering procedure. This enhanced cortisol secretion was in turn related to longer time to heal.

These findings suggest that the ability to regulate the expression of one’s anger has a clinically relevant impact on wound healing.

Find the study here.

So, next time your boss yells at you, or some guy cuts you off on the highway, you will have the satisfaction of knowing that they can’t heal as fast as you.