Archive for September, 2007

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Brain asymmetry and why it is important

As most people know, different parts of the brain are assigned different tasks. The brain is lateralized – asymmetrical, by design. And, there is a very good reason for that. The split-brain design allows us to process many things at once. We owe our ability to multi-task to the hemispheric design of the brain.

Like the human brain, many modern computers are coming with essentially 2 hemispheres, or Dual Core processors. When one processor is busy checking email, the other can be scanning for viruses. This is analogous to how brain hemispheres work.

To test the theory of the split-brain advantage, Aneglo Bisazza and Marco Dadda  of the University of Padova bred two different strains of the same species of fish. One strain was bred to have asymmetrical brains like most vertebrates, and the other strain was bred with symmetrical ones (both sides processing the same thing).

Both fish groups could handle a single task equally well, such as catching shrimp. But, if a second component was added to the mix –  a predator – the split-brain advantage became quite apparent. The symmetrical-brained fish took twice as long to catch their prey, having to divide their attention between watching for prey and catching a meal. Their asymmetrical cousins, on the other hand, were able to focus on both tasks at once, and the introduction of a predator hardly affected their ability to catch food at all.

Asymmetry is absolutely essential in order to complete the complex tasks we take for granted. In a conversation with someone, the left brain will be processing the verbal language, while the right brain interprets tone and inflection.  If you are asked to imagine a scene, the left brain will create the details, while the right brain handles the overall shapes, sizes and their spatial locations. Without both sides processing all of these details at once, we would never be able to function at the advanced level we do.

But there are also disadvantages to asymmetry. Certain tasks may be easier to execute on either the left or right side of your body. The left side of the human face tends to be more expressive because it is controlled by the right hemisphere. Most people are right-handed because the left brain is usually dominant. According to Bisazza and Dadda, the aforementioned fish will tend to guard one side of their body over the other and as a result their predators will tend to approach them from the unguarded side.

Brain asymmetry means that both hemispheres have to work closely to ensure a smooth ride, and having an overly dominant hemisphere is invariably a bad thing.  Brain damage to the right hemisphere can leave a person indifferent and uncaring, while brain damage to the left can leave them with severe depression, or without speech.

You’ve probably heard quite a lot about “hemispheric synchronization” already (just look at how many brain stimulation companies have “sync” in their names).  The word synchronization can be misleading in the context of the brain, since it implies that the two halves are processing information in the same way, which isn’t usually the case. However, brain activity can be more evenly distributed across both hemispheres. In a healthy, intelligent brain, the two halves are communicating fluently, and working closely together. There is a reduction in dominance of one hemisphere over another.

To see for yourself the manifestation of hemisphere-specific neural processing, check out the below video to see what happens when the corpus callosum, which facilities cross-hemisphere communication, is severed:


The “Guardian Response”

In the realm of Brainwave Entrainment, the Guardian Response is enemy #1.

To give you an idea of what the Guardian Response is, there was a recent article in the Independent about Mind Machines, specifically the MindSpa. The author is pretty skeptical at first, and doesn’t really know what to expect. Not surprisingly, his first experience is not all that great. Here’s an excerpt:

The programme starts with a 10-second countdown that’s supposed to give me time to get comfortable, but instead makes me nervous. Three… two… one… suddenly 12 white LEDs in the glasses start flashing maniacally, while at the same time my ears are bombarded with a rhythmic electronic drone. I feel like I’ve been locked inside the engine room of the Starship Enterprise. Never mind Zen-like calmness – I fear the MindSpa is going to induce an epileptic fit. I try to relax and focus on my breathing but five minutes in I start feeling queasy. It’s time for a break.

According to Dr Ruth Olmstead, a psychologist and expert in “Auditory and Visual Stimulation” (AVS), I’ve experienced a “guardian response”. Olmstead, who developed the MindSpa programs for Californian firm A/V Stim, says: “The first time people try it they’re often too busy thinking about it to relax.”

Later on in the article, after some research and a few more tries, the author was able to bypass the Guardian Response and have a very pleasant experience with the technology.

Brainwave Entrainment (BWE) is not like drugs or alcohol – if you are not in a conducive emotional and physical state for relaxation, there is no amount of BWE that can make relaxation happen. If this is the case, the conflict between what the stimulation is trying to do, and your own resistance to it, often causes opposite effects such as anxiety, frustration, headaches or queasiness.

The Guardian Response can actually be due to a number of factors, such as lack of rapport with the therapist or conflicting beliefs.

Here is how David Siever describes this problem:

The guardian response, simply put, is a condition of anxiety that a person may develop when placed into a situation to which he/she feels apprehensive. The guardian response may be produced when a person is in an unfamiliar, uncomfortable setting or where that person is expected to engage in an activity which incites anxiety. Many people have a guardian response to dissociating. Because both L&S and AVE can produce dissociation, they may also elicit a guardian response in some individuals.

Clients may be concerned about being pressured to purchase a product or service, they may have uncomfortable feelings regarding their rapport with their “therapist.” Some may feel anxiety about doing a simple task such as performing a math question or even relaxing. A client may be nervous about using the equipment, or may feel too “exposed”. A client may be nervous about having “dark” thoughts or may have conflicting religious beliefs, moral values or medical beliefs prohibiting him/her from having a good BWE experience. In any of these cases, the client will probably develop a guardian response which will manifest itself as:

– uneasiness/tenseness
– squirming/fidgeting
– need to visit the washroom
– uncooperative
– refusal to relax
– refusal to drift away during a session
– refusal to complete a session
– high GSR activity
– an immediate “bad” experience
– poor, boring or sickening visuals

Often, an unsettled client can be comforted into having a better experience through conversation or by playing a relaxation tape. If the AVE concept, for some reason, conflicts with the person’s belief system, there is typically nothing that can be done except to end the session and thank the person for being there. This person may try a session a year or two later when his/her belief system is prepared for the AVE experience, at which time she/he will likely have an excellent experience.

The Guardian Response is the reason I have had such a frustrating time getting some of my friends and relatives to use BWE. I have a teenage relative who has always been very curious about the technology – when I demonstrate some new hardware or software to the family, she’ll always be the first to want to put it on and try it. The problem, of course, is that we’re usually not in an appropriate place for any type of relaxation, and she will feel the need to giggle or talk to her friends while using it.

The more skeptical beginners can have similar initial problems. Although very well studied, BWE is not yet mainstream. Therefore it is understandable that people would be skeptical at first. Beginners who are still in the process of researching the technology may find it hard to “let go” and allow the stimulation to take over. I make a special effort to present as much research as I reasonably can beforehand, but this is something that is hard to explain in a few paragraphs. Even Dr. Huang has mentioned problems with this. If you can get past this barrier, and convince them to give it an honest try, even the most cynical beginners will have very effective experiences. Some of the most dedicated users of BWE technology I know started out like this, including myself. Skepticism is healthy, and in the end won’t make a bit of difference from a neurological perspective. The trick is getting people to try it a few times.

Creating the first experience 

Luckily, most people interested in our products have done quite a bit of research and have already decided to make a concerted effort to try it. The real challenge then is creating a pleasant and convincing first experience. Presenting instructions and tips before every session is essential for beginners. Using background files like nature sounds or ambient music can help create a more familiar experience. Verbal guidance and induction scripts are also quite useful. We use a questionnaire (called a Wizard in NP2) that asks a series of questions about your personality, and what kind of sounds you prefer, and then gives recommendations based on data and feedback collected from thousands of users.

Even so, it can be a high-wire act trying to balance a user’s first experience with effectiveness and neural response. The user might have a relaxing first experience if there is so little entrainment that all you hear are nature sounds, but the actual neural effect of the session may be severely diminished. Did you know that the most effective audio entrainment is from clicks? Unfortunately, clicks are so abrasive sounding that they are completely unusable in commercial products, even for experienced users of BWE.

The Guardian Response is a real challenge; there is a lot of work to do to make everyone’s initial experience as fantastic as someone who has been using this technology for years. If you are a new user: remember to read everything you can beforehand. Before starting your session, listen to it for a few seconds. Does it sound relaxing to you? If not, customize the session to yourself. Consider your first session a mere experiment. Throw away any expectations or anxieties you have about it. Lay back, relax and let the stimulation do its work.

Using neuroimaging to analyze mind-over-body effects

NPR brings us one step closer to understanding the mind-body connection in a recent segment on the mysterious placebo effect. Using relatively recent neuroimaging techniques, researchers are able to isolate the specific neural effects of belief and expectation.

Take a listen:

Sleep learning in the 1920’s

Here is an interesting news blurb from a 1923 Time Magazine about radio operators who accidentally stumbled upon the idea of sleep learning:

The accidental falling asleep, with the phones on his head, of a student in training for a job as radio operator in the U. S. Navy led to a discovery which will vastly shorten the process of manufacturing experts in wireless telegraphy. While the code and its translation were coming through the ether, the brain cells of the sleeping man, in a state of plastic receptivity, were absorbing the meaning of the dots and dashes and forming new associations. On waking, he was able to repeat accurately everything he had received in sleep. Psychologists say that such results are feasible because of the automatic, repetitive nature of the material conveyed to the dormant brain.

Navy officials immediately instituted tests of the method at Pensacola, Fla. Twelve students who were making unsatisfactory progress were tried out. After two nights, during which the code was sent to those students in sleep, ten had learned the lesson, and the other two had left the class before completion of the experiment. The instructors now report that ” the experimental stage is past, and the method may now be termed a standard one.”

Today the concept of sleep learning actually focuses less on unconscious sleep and more on the “twilight state” between alpha and theta. This highly receptive state is useful not only for memorizing rote facts, but for conceptualizing them, and forming new ideas. This is the state we focus on in one of the learning tools in NP2

Thanks to Mind Hacks for this.

Weekly Brain Video: Memory techniques

Andi Bell isn’t an autistic savant. He wasn’t born with photographic memory. Yet, he is currently the reigning champion in the speed category of the World Memory Championships.

This is possible because of a memory technique Andi uses, which is explained in the following videos:


Part 2:


This technique reminds me a lot of Memory Pegs, which many of you may have already heard of.

The basic idea of these memory techniques is to associate a story or image with what you want to remember. The more humorous and outlandish the story, the better. For example, if I wanted to remember to buy turkey and paper towels at the store, I might picture a live turkey comically trying to escape from a wrap of paper towels.

I use this technique when I play Brain Age, which lists words much like the experiment in the above videos. I associate 2 words with something comical, and move to the next pair. Usually, I can remember all of them, and I certainly don’t have prodigious memory.

To me, the interesting and unique part about Andi Bell’s technique is the use of a familiar route to further reinforce the memory pathways. Start at the door of your house, associate a memory with it, walk into the foyer, associate a memory with that, walk through the living room, a new memory, and so on. This is brilliant.