Archive for April, 2007

Weekly Brain Video: God and the Brain

Today’s video is a fascinating documentary on how temporal lobe epilepsy can cause some intense spiritual experiences, even in those who are not religious.

There was a lot of news on this subject around Easter, and I have actually been meaning to write a longer blog post on it for some time. I hope to get around to that soon.

Enjoy! :)

[youtube]NYlMEOGMAFY[/youtube]

Part 2: http://www.youtube.com/watch?v=7vlUnhRR5NI

Part 3: http://www.youtube.com/watch?v=dpwyYgJq9A4

Part 4: http://www.youtube.com/watch?v=AT4_a4MfAls

Part 5: http://www.youtube.com/watch?v=7ZWJJA6RKpA

 

 

Alpha’s involvement in memory, and how 10 hz flicker can improve it

It is well known that episodic memory - the ability to recall events, times and places - degrades as we get older. What is interesting is that the strength of Alpha rhythms in the brain also decreases with age, and falls sharply with diseases such as Alzheimer’s.

This is important because alpha is theorized to be intimately involved in the encoding of certain types of memories. It has been well known for some time that drugs used to modulate slow rhythmic EEG activity can actually enhance memory. More recently, brain stimulation in the form of a flicker is showing even greater promise in this area, and is offering the incredible possibility of a completely drug-free solution to age-related memory problems.

In March of 2006, a paper was published in BMC Neuroscience which outlined the effects a 10 hz flicker had on a difficult memory task, showing very promising results. The performance of older participants on memory tasks was as low as would be expected given their advancing years. However, once the Alpha stimulation was introduced, their memory performance shot up to that of typical young adults!

 

The Method 

Unlike many of the effects produced by audio-visual stimulation, this one seems to be extremely frequency specific. A mere .5 hz difference between flicker rates made the difference between a positive effect and no effect at all. 10 hz and 10.2 hz seem to be the “magic” frequencies studied in this paper.

Also interesting is the duration of the flicker: only 1 second! Participants were asked to memorize words as they appeared on the screen. Before each item was presented, a 1 second burst of 10 hz alpha stimulation was administered using LED lights, set up in their peripheral vision.

 

Why would such a brief stimulation period have any effect?

The study mentions that this could be because alpha’s involvement in memory formation is exceptionally brief. For a rapid moment as memories form, Alpha synchronizes. The theory is that short bursts of alpha stimulation increases this synchronizing effect, leading to enhanced memory. The hippocampus, which is involved in memory formation, may be the brain structure that makes this possible. There is evidence that slow-wave activity of this type seen in the hippocampus facilitates memory formation.

On the other hand, the study also notes that the duration between flickers was also very brief, so the alpha-inducing effects could have carried over from item to item. The effects of longer durations, and any long-term effects of this stimulation, have yet to be studied. Still, this is all very promising, especially since we know from other research that long-term, permanent alpha enhancement is very possible.

 

Other interesting tidbits about this research:

· The flicker’s effect does not appear to be retroactive. In other words, it was only AFTER the flicker that memory appeared to be enhanced. Memories encoded before the flicker were unaffected.

· The brightness of the LEDs correlated with greater effects. The brighter the LEDs, the more enhanced memory became. 

· The memory-enhancing effects seemed more pronounced in the elderly, but the study did mention previous work that indicated alpha also enhanced memory in young adults!

· Other previous studies have indicated that theta stimulation could improve memory consolidation after learning has already taken place.

 

Here is the paper, if you are interested in taking a look for yourself: http://www.biomedcentral.com/content/pdf/1471-2202-7-21.pdf

 

The best part about this study is that the LED lights were positioned around the eyes, not in their direct line of sight. In fact, some participants didn’t even notice them!

This has encouraged me to start using the new open-eye glasses more:

 

 

The Mystery of Sleep and the lucky few who don’t need it

All animals need sleep, even insects. But as ubiquitous as sleep is, it is still very mysterious. Why we sleep, and why humans need an average of 8 hours specifically, is still a subject under much debate. One of the dominant theories is that sleep is a time when the body repairs itself. We know that growth hormones are released during sleep, and that sleep depravation has many negative effects on the immune system.

Another theory is that long term memory is consolidated during sleep. Sleep researcher Matthew Wilson, of MIT, recently did some fascinating work into dreaming in particular. He recorded the brains of rats as they ran through a maze, noting the mental activity produced. Later, as the rats were sleeping, he saw the same activity, only more rapid and played in reverse, as if the rat’s mind was rewinding a VHS recording of the run through the maze! Dreaming, Wilson asserts, is a form of “mental cleaning”, where the brain determines what memories it should keep and what to throw out.

Another theory may help us understand why all animals sleep, even those without long term memory. Bruce O’Hara, a professor of biology, explains:

“If we accept the premise that all animals sleep, then it looks like there’s something special about neurons, about basic energy requirements. Neurons are among the cells that have highest energy requirements. Our brain, 1 or 2% of our total bodily weight, uses up 20% of our energy; so the brain is the most energy-demanding organ we have,” O’Hara explains. He concludes that energy usage is one very possible function of sleep. Neurons require this loss of consciousness to slow down just enough so they can replenish themselves for normal functioning. “It’s hard to get solid data to support that, but no data I know of refutes the idea.”

So, it seems sleep is a necessary side effect of owning and maintaining a brain.

 

Needing less sleep, or none at all!

Even so, the mystery of sleep deepens when you find out that some people need much less sleep, and in rare cases people hardly require any sleep at all!

The longest recorded period without sleep is an astounding 33 years, performed by 64 year old Vietnamese man named Thai Ngoc, who claims to have lost his need for sleep after a sickness in the 70′s. Surprisingly, he experiences no ill negative effects from this condition, not even the normal sleep deprivation effects such as fatigue, loss of concentration, and so on. Under normal circumstances, people who lose even a few days of sleep start exhibiting cognitive symptoms usually only present in senior citizens.

Scientists have found a gene that could be responsible for needing less sleep, which they call “Period 3″ or the “Clock Gene”. While most humans need an average of 8 hours of sleep, people with specific variants of the Period 3 gene seem need to much less – sometimes as little as 4 hours of sleep a night. Many notable people through history have claimed to  need less sleep – Michelangelo, Napoleon, Thomas Edison all claim to have only needed 4 hours of sleep a night. In modern days, Madonna, Jay Leno, Margaret Thatcher and many others say the same thing. It seems to be more prevalent in highly ambitious, driven individuals.

I saw a documentary on sleep years ago that followed an even more amazing case of a father and daughter who only needed 1-2 hours of sleep a night. They both held 2 jobs and experienced no negative symptoms. I tried to find this documentary for our weekly brain video, but couldn’t locate it online.

Other genetic variants can play a role in sleep as well. Michel Jouvet, famous neuroscientist and sleep researcher, once studied a 27 year old man with Morvan’s fibrillary chorea, a genetic disorder that kept him from sleeping. He went months without sleep, yet did not suffer any negative consequences associated with sleep depravation. However, instead of sleep, his nights were full of dream-like hallucinations. Perhaps he did not reach a state of sleep as we know it, but his body found a way to compensate somehow, and work around his genetic differences.

Also interesting is how we perceive the amount of sleep we’ve gotten. A study by Dr. Allison Harvey, of Berkley, measured how much sleep a group of insomniacs actually got compared to their perception of it. It turns out that they only received 35 minute less than those who had no trouble sleeping, yet when asked how long they had slept, the insomniacs reported only 2-3 hours of actual sleep. Amazingly, when they were told that they had gotten a good night of sleep, many of the symptoms of sleep depravation disappeared!

So, in many ways, our perception of how rested we are affects how we feel during the day.

Many users of Brainwave entrainment also report a reduction in sleep needs, particularly in the first few months of use. Deep relaxation sessions like those targeting Theta waves, are said by many to replace up to 4 hours of sleep. In a way, this makes sense since Theta is close to the mental state of sleep, and when Theta acts as a kind of “cat nap”, it could naturally reduce your need for sleep. However, what is more interesting is that even people who never use Theta sessions often report the same effect! We even have users of Beta sessions (basically the opposite of sleep) reporting that they need less sleep yet feel more energetic during the day. Though this effect is often temporary, it still raises many intriguing questions.

Not surprisingly, drug companies are working fervently to come up with a way to reduce sleep needs, beyond the jittery effects of Red Bull and coffee. The drug Modafinil seems to help the brain mimic the effects of the “Clock Gene” variant, allowing users to only sleep 4-5 hours a night and still feel as refreshed as ever. A new drug being tested called CX717 promises to allow someone to remain awake for 36 hours or more without the negative effects of caffeine.

I do wonder if there are any long term problems with sleeping less, even if we are genetically gifted to do so. I read one study that indicated it could be a problem for women more so than men. It seems to me that if there wasn’t a major biological disadvantage to sleeping only a few hours a night, everyone would be doing it by now.

Still, I can’t help but envy those lucky few who can survive on 4 hours of sleep. I am decidedly average, needing almost exactly 8 hours to feel normal, barring any cat naps or theta sessions I’ve used. Any more than 8, and I feel dazed – any less, and I feel sleepy. Who knows what wonders people could produce with an extra 4 hours of time each day!

Implantable component for “Brain Radio”, and the return of the clapper, the brain-clapper!

Medtronic, a company known for producing deep brain stimulators, is working on a surgically implantable “radio” device capable of monitoring and influencing brain activity. It may be used to ease the symptoms of diseases such as Parkinson’s (shaking), or to reduce severe forms of depression.

Here’s a quote:

“We want to measure the average activity of thousands of brain cells,” said Tim Denison, a senior principal engineer at Medtronic Neurological Technologies, who presented the ISSCC paper. “Essentially we want to build a brain radio that we can tune to the particular frequencies of the patient,” he added.

An article in EETimes goes into some of the challenges they have faced in developing such a device for the brain. It’s short, but interesting: http://eetimes.com/news/latest/showArticle.jhtml?articleID=197005915 

Also, remember the “clapper” from the 80′s? You know, Clap-On, Clap-Off?

The Medtronic engineer demonstrated a “brain clapper” that monitored alpha waves to tell when a subject’s eyes were open or closed. By opening and closing his eye in a demo video, Denison was able to turn a light on and off in his lab.

“You won’t see Medtronic marketing a ‘brain clapper’ anytime soon,but you will see us apply this technology to a variety of diseases”

Actually, you could do the same thing with a regular EEG. Below is a screenshot from one of our EEGs. You’ll see how noticeable the alpha spikes are when the eyes are closed

 

Weekly Brain Video: Mirror Neurons

Mirror Neurons are a relatively new discovery, and are being touted by many as one of the most important discoveries in the last decade of neuroscience. There was a lot of media attention on these buggers last year, primarily because of what they indicate fundamentally about human social interaction.

Essentially, Mirror Neurons are built to respond to actions that we observe in others. The interesting part is that mirror neurons fire in the same way when we actually recreate that action ourselves! For example, if you move your arm up and down groups of motor neurons in the brain will fire. But, if you observe someone moving their arm, many of those same neurons will fire in the same way!

Now, if you have read the documentation of our Neuro-Programmer product, you might not be too surprised by this. One of the fundamental concepts behind the program is that neural responses to observed or imagined actions will be similar to the brain activity of actual events, and this is one of primary reasons why creative visualization is so effective. In a sense, mirror neurons have been known about and studied for a very long time. Ask any professional athletic coach about visualization and you’ll hear all about it. Ask anyone who feels like they can perform huge feats of kung fu after a Bruce Lee movie. Ask me why I can’t bear to watch the particularly embarrassing scenes from The Office.

But, it is great to see analysis going into the exact neurology behind this brain phenomenon. And not only that, but it is giving us valuable insight into brain disorders. Defective Mirror Neurons are now thought to play a role in Autism, since many Autistic individuals often have perfectly functioning brains, but seem to struggle in social situations.

Mirror Neurons are also helping to explain how humans interact, and are showing empathy to be a much more powerful and pronounced neurological process than previously thought. On a related note, in EEG tests mirror neuron responses seem to be stronger in women than in men. ;)

[youtube]WM9MaIU3zVU[/youtube]

 

Also, here is a link to another video on Mirror Neurons and Autism: http://www.youtube.com/watch?v=_8WV1zAh9zU

 

Music and the Brain

Music has a special place in the world of brain science. If you take away human actions required for survival (breathing, eating, sleeping), listening to music may be the most universal human activity on the planet. Every culture in the world has it, and nearly everyone enjoys listening to some form of music.

There is a new and interesting branch of Neuroscience emerging called Neuroesthetics, which focuses on understanding the neurological mechanisms behind music, among other subjective sensory experiences such as art, gourmet food and sweet smelling perfumes. In a study by Dr. Levitin, a former rock music producer turned neuropsychologist, 13 subjects were analyzed under an MRI while listening to classical music. First, the music triggered various areas of the forebrain, as the sound was analyzed, broken down into rhythm, tone, structure, etc. Then, more importantly, the brain’s pleasure centers were activated, releasing dopamine to give a sense of pleasure and reward!

It is because music results in the release of pleasurable chemicals, Levitin supposes, that memories of music become so sharp. Ask anyone to hum one of their favorite songs and it is likely they will remember nearly every note and rhythm change. Considering how complex music actually is, this is quite a feat!

Pleasure centers being activated also helps explain the universal appeal of music, and the profound impact it can have on mood. What is particularly interesting is that all this seems hard wired into us. Not our musical preference, obviously – that is cultural – but the fact that everyone responds to some form of music is highly unique. Why are we built to love music? This is yet to be determined.

Music and your personality

As John Cusack said in the music-centered romantic comedy High Fidelity:

“What really matters is what you like, not what you are like”.

Perhaps because music is so universal, it is also one of the most popular topics of conversation, particularly with people who are just getting to know one another.

In a study by Rentfrow and Gosling, called “The Role of Music Preferences in Interpersonal Perception”, subjects were asked to get to know one another over a 6 week period. Their topics of conversation were noted. By far, music was the most prevalent, with 58% of participants discussing music.

Whether we are consciously aware of it or not, there is something intimately revealing about a person’s musical tastes. Your personal top 10 list may reveal more about you than talking at length about hundreds of other topics. The study tried to codify this by having all the participants take a standardized personality test.

Here are some general correlations mentioned:

- Likes vocals: Extraverted

- Likes country music: Emotionally stable

- Likes jazz music: Intellectual

Personally, I enjoy vocals but tend to focus on the music itself as the base for my musical preference. I’m fairly introverted, so I suppose for me that fits. However, while I respect the enormous technical mastery it takes to play jazz, it has never struck an emotional chord with me. Am I unintellectual? These results are kind of confusing to me, but then it doesn’t seem like many other genres were analyzed - or at least they weren’t mentioned. I would love to see more studies go into this.

I have never really asked myself why I prefer a certain type of music. In many ways it is cultural for me, growing up in a musical family, with my father in a celtic/folk band that would play every Sunday. In another way, it is technical – because I can play music, I appreciate music that is hard to play. But, as the jazz thing clearly shows, that is probably not what results in a release of those ever-important pleasure chemicals.

So - what kind of music do you like? And – what does it say about you?

Music and your intelligence

For at least a decade, millions of parents have been playing classical music to their infant children in hopes of raising their intelligence in some way. We have all heard of the Mozart effect. Like an urban legend, nearly everyone has heard from a friend or a friend of a friend that Mozart will make you smarter, that the part of the brain that analyzes music is also involved in math and a million other activities.

So far, there actually hasn’t been much analysis on what effect early musical listening has on intelligence. However, there is growing evidence that learning to play music has many beneficial effects. Increased spatial intelligence for one, but also other benefits. Nina Kraus and Patrick Wong, both neuroscientists at Northwestern University, recently studied 20 participants, some with at least 6 years of musical training that started before the age of 12, and the others with only 3 years of training or less. They were asked to watch a movie of their choice while also listening to a language that was unfamiliar to them: Mandarin. They found that musical training correlated with the ability to decipher the tones used in Mandarin (which is a tonal language). They also found that musical training helped participants zero in on these sounds despite the ongoing movie. This analysis has lead the researchers to conclude that musical training may enhance a variety of auditory brain activities – in other words, musical training is not just training you to play music.

The good news is that many people fall into this category. The participants studied were not musical virtuosos – just every day people with early musical experience.

Unfortunately, I haven’t read anything yet to indicate that music helps with math. Considering how much I struggled with math in school, while simultaneously playing music daily since I was 8, I’m not sure there is much correlation to be found there.

Music and the Ancient Brain

Another interesting finding by Kraus and Wong, was that the differences between neural responses of participants was largely in the brain stem, one of the oldest parts of our brain, and a part that is normally only involved in controlling heartbeat, breathing, and other critical body functions. Not a place you would expect to find a response to music!

The research by Dr. Levitin (mentioned at the beginning) found musical responses in the Cerebellum, an area associated mostly with body movement, and also a comparatively ancient part of the brain. Levitin said that as the brain internalizes the music, the Cerebellum starts reacting every time the song deviates from its normal melody or tempo.

It is amazing that these ancient brain structures are so involved with the music, and could be yet another clue into why we react so strongly to it. Knowing this could explain why I often get a very physical reaction to music (tingling of the skin, for example).

Music and a thousand questions

Still, these studies have raised more questions than answers for me. How is our music preference affected by our personality? Why does the brain devote so much energy to experiencing music? What is lost in the brain if you are deaf, brain damaged, or musically deprived?