Theta Synchrony

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Hi

I've recently read Gruzelier's theoretical basis for alpha theta training. My take away message was that the underlying mechanism is really theta left frontal to posterior synchrony. I'd be interested in your thoughts.

Regards

Mark Baddeley

alternative method for training down theta?

Hello ,

I am impressed with the careful attention to detail you have undertaken in this matter. Since you asked for comments, here are mine.

Roughly speaking there is good theta and bad theta. Bad theta is polymorphic. This means that the observed periodic phenomena in the EEG occur roughly 4-8 per second but have a varying morphology that is not sinusoidal. "Good" theta is rhythmic and sinusoidal like eyes-closed alpha and is primarily frontal midline.

Bad theta is indeed a hallmark of a variety of malfunctions such as ADD. In many cases it is due to maternal immune activation. In other cases it is due to current or on-going stimuli disrupting homeostasis.

Neurofeedback uses Fourier transforms to isolate primarily the rhythmic good theta. Normally this is roughly midline. You are correct in assuming that a left frontal concentration of theta (good or bad) is an aberration. It is essential to remember that on occasion localized theta may be a manifestation of focal abnormality (vascular, neoplastic, degenerative, traumatic, inflammatory, etc.)

However, you talk like the theta was not only bad but might also be a culpable agent with an agenda. In such a scenario we usually agree to attack the aggressor (the theta amplitude). But there might be another interpretation.

Delta to gamma brainwaves are ALL slow waves compared to the 500-1000 Hz waves that are included in the panoply when one looks under the hood. Especially delta, theta and alpha are all bases for long-distance network communication. So if you see theta segregated to an isolated region you know you are dealing with a loss of long-distance integration and synchrony. The goal then is NOT to suppress some local theta (or gamma or whatever) but to reintegrate it so that it can continue its role as a bases for network communication.

It is not immediately obvious that excess focal theta can be reduced by increasing global theta synchrony. However this may be the case.

You may risk unexpected outcomes by dealing with theta amplitude while ignoring any possible phase changes between the theta waves in various parts of the cortex. The well-documented fact that the EEG exhibits what is called a 1/f (one over F) power law can give us clues that are not immediately available elsewhere.

The 1/f power law of the EEG clearly enforces that fact that phase shifts (phase modulation) at low frequencies (e.g., delta and theta) control amplitude modulation at the higher frequencies (beta and gamma). This means that the normal essential fractal dimensionality of the EEG may be violated by certain attempts to control low frequency amplitude (e.g., theta training) without attention to the resultant shift in distribution of higher frequencies (beta and gamma). I propose that this is the basis for many of the adverse outcomes of neurofeedbac.

Quite a few researchers (Aftanas, Varela, etc.) have shown that long distance theta and alpha synchrony are essential for valid perception.

My experience (unpublished) has shown that focal concentrations of theta can often be relieved by up-training theta alpha and gamma synchrony between the 'problem' area and another remote area.

Thus, an apparent "accumulation" of theta in the left frontal region may be relieved by recognizing that theta is a long-distance global synchronization signal. Any focal accumulation signifies focal segregation - not long-distance integration and synchronization. I believe we will be able to show that focal amplitude accumulations can be treated by reintegration by phase synchronization.

It also good to remember that if there is schizophrenia or bipolar disorders anywhere in the family line, then there is going to be a 20-40% reduction in frontal glutathione leading to neuronal irritability. Increased left frontal theta may be an adaptation when normal cognitive and historical networks cannot cope for chronic stress. As a result you can often expect increased anxiety as a result of treatment. This is a good sign. The anxiety is usually very primitive and the client was not shown self-regulation. The left frontal slow waves may be a mechanism to cope, but lead with other problems such as depression and attention issues.l

Gamma normally is "nested" within theta. Therefore a focal accumulation of theta can alter the ultimate binding activities of gamma. Different mediation techniques (imagery, mantra, emptiness) create different cortical gamma distributions. The 1/f power laws show that patterns of theta phase relationship enforce focal gamma amplitude changes, such as are seen with different meditative approaches.

Aftanas, et al, have shown that in mature healthy meditators, left frontal theta (and alpha) is especially strongly phase synchronized with the left parietal cortex (P3), the precuneus region (Pz) and the right parietal cortex (P4).

I look forward to learning the results of your continued investigations.

Best wishes,

Dailey

www.growing.com

www.cortexercise.com

From: [mailto: ] On Behalf Of ZumbachSent: Friday, May 18, 2012 7:46 AM Subject: Re: alternative method for training down theta?

It isn't very hard to see the difference between an errant eye blink and a burst of theta lasting several seconds so I'm not too worried about that. It is important to keep the eyes resting partially closed so that one only needs to blink occasionally, but you already knew that.

I would argue that using all four channels is a fine idea on the principle of the fact that more data is generally better and that it gives me the ability to see the bursts of theta as they progress all the way across the left frontal. I would also assume that it would be better to make sure to train the theta down all the way across the left frontal instead of isolating the feedback to one small area.

I don't think theta is bad but I'm under the understanding that theta production in the left prefrontal is characteristic of ADD and that the more there is, and the more frequent the bursts, the worse the symptoms are (according to this book: http://tinyurl.com/6qxvtz8). Are we saying that protracted bursts of 4-7hz activity in the left PFC is a desirable thing?

I'm also correlating these bursts of theta to breaks in protracted concentration during alpha-synchrony/meditation training. With my latest design I can calculate the exact amount of time I'm in synchrony while meditating and I'm up to an average of 45 minutes out of 60 for most sessions (baring something foolish like caffeine consumption) and I see some strong evidence that these waves of theta washing over the left prefrontal seem to be the cause of my interrupted attention during the remainder. This is the impetus for my action.

Thanks for you input Pete, DZ

On Thu, May 17, 2012 at 11:32 AM, pvdtlc <pvdtlc@...> wrote:

Of course the very first thing to be aware of is that every time you blink or move your eyes, you're very likely to produce a burst of slow activity that looks like theta or delta. If that's what is happening, you may end up training yourself not to blink, but you won't have much effect on brain activity.

Second thing is that theta around 7 Hz is actually a GOOD frequency, since it involves connection with the hippocampus or memory center..

Looking at one thing in one place and deciding what to train is probably not the best way to decide on a training plan. What are you noticing as a problem in your performance/mood/etc that you think is related to this theta? Or have you just read that theta is "bad"?

If you are training in a very small area as you are describing, aside from the fact that you have 4 channels and really want to use them all, I can't see any benefit to 4C over 1C.

Pete-- Van Deusenpvdtlc@...http://www.brain-trainer.comUSA 678 224 5895BR 47 3346 6235The Learning Curve, Inc.

On Thu, May 17, 2012 at 12:13 PM, Zumbach <zumbach@...> wrote:

[Attachment(s) from Zumbach included below]

Hey everyone,

I realized recently that I have a great deal of theta popping up between FC3 and F3 and decided to start training it down. I have some experience using bipolar montages but have decided that I am against using them. Everywhere I read about bipolar setups (here, the Othmers, quantitative EEG textbook) it seems apparent that no one actually knows what is happening during the training. We may be training the signal up at the active point or down at the active point, down at the reference or up at the reference, changing the phase relationship at either location in one direction or another, but in the end we have literally no idea what is going on other than a vague conception that the electrical activity at one site is now more similar or more different than the activity at the other.

For this reason I have created a new design based on, of all things, the alpha-synchrony design that Les Fehmi uses. The logic is that I can put four electrodes between FC3 and FP1 and then sum the theta at these locations. I then set a threshold around 85% and set it to "decrease" so that when, for example, there is a burst of theta in my left frontal region pacman stops moving. I find the inhibit only strategy appealing because once you train theta down the remaining activity will be whatever frequency of beta my brain is most comfortable making, as opposed to trying to get my brain to make a particular frequency of beta.

What are people's thoughts on this strategy and my rationale? I would really appreciate any feedback at all.

Zumbach