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.
References:
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.
But what about the Buddhists?
Others find the idea of no free will a comforting idea. I admit, it does have its appeal. Here is a great quote from Einstein:
It is intriguing to think of how much of the brain is a continuum, and how much the definition of “normal” shifts from era to era. Traditionally black and white concepts such as genius, evil and madness, are challenged by new discoveries, and new looks at the way the brain processes impulses and inhibits behaviors. To many of us, this is old news. As any long time owner of a brain will tell you, it is hard to deny occasionally walking the line between normal and madness, or between genius and mediocrity. Recent surveys of the general population add further evidence to this. “Do you ever think people are talking about you?”, “Do you ever hear voices?”, “Do you ever think you might have special powers?”, “Do you ever talk to yourself, out loud?” Many people considered normal answer yes to questions usually reserved for people with some form of psychosis! I admit I have been talking to myself and openly berating malfunctioning electronic equipment since I was old enough to speak. In truth the brain often seems like a gray area in more than just color, and the definition of normal seems to be shifting.
Despite the evidence to the contrary, most of us feel fairly normal and well adjusted. In fact many people feel they could use an enhancement to their creative side. Creativity is “in”, and any resulting eccentricities are an acceptable side effect. Corporations pay big bucks to have their employees attend creativity-enhancing seminars. From a brainwave perspective, bursts of creativity seem almost inevitable. When I first started using entrainment I was amazed at the myriad of unrelated thoughts that would pass through my head. Memories from years past would surface, and my mind would start connecting ideas I never considered before. Creativity itself seems to be the act of connecting two previously unrelated ideas to form a new one. It is no surprise that ADD is linked to creativity. Having a mind that is naturally “out of the box” and constantly jumping from subject to subject can be an advantage during a brainstorming session.
With elections only a few days away here in the States, I find myself wondering – as I always do every 2 years – what is behind the vote I’m casting, and the votes of others. Although most of us probably think we vote on issues alone, research on the brain suggests that many people vote with their identity instead. If you tend to relate to a certain party’s identifying characteristics, or perhaps if your family has voted with a particular party for generations, your subconscious will tend to shift your thinking in favor of that party. There is a neurological basis for this. In 2004 Drs. Freedman and Iocaboni, at UCLA, used MRI to analyze which areas of the brain “light up” when subjects are shown political content associated with a particular candidate. If the candidate was already preferred by the subject, neural areas associated with empathy became highly active, while areas of negative emotion lit up when presented with information associated with opposing candidates. The content of the message itself is less important than the context in many cases. Subconsciously, the mind finds a reason to dislike messages seen to be outside of our own identity. It is interesting to observe this happening in my own brain as I view the hundreds of campaign ads bombarding the airwaves, some of which are hard to affiliate with a particular party until well into the commercial.
