Global and Regional Connectivity

When we spoke about frequencies earlier, we said that slow frequencies like Delta, Theta and Alpha are not produced by neurons in the cortex. They are frequencies we see when cortical neurons are not working. These lower frequencies can be thought of as transmissions which are broadcast throughout the brain from structures in its center. When neurons in the cortex are resting, they may tune in to any of these frequencies and begin to resonate to them. Read more… […]

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Phase and Coherence

Imagine we are in a blimp floating over a great stadium where the Beach Boys are performing a farewell concert. Tens of thousands of people are standing on the grass in front of the stage. The Beach Boys begin to sing their old favorite ballad, Surfer Girl. Audience members link up into long rows, putting their arms across the shoulders of the person on either side, and begin rocking back and forth to the rhythm of the music. From above, we can see that all the rows are … Read more… […]

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Connectivity: Coherence/Phase/Synchrony

Certainly the brain’s billions of neurons create an energy-producing system, but it is also an astonishingly complex self-adjusting communication system. A cellular phone network has the potential to facilitate communication over a great area, but if every time I call someone his phone is turned off and when he tries to call me back, mine is out or range, the communication doesn’t happen very well. Read more… […]

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As with any other part of the body, it is important for us to know how things change in the brain between resting, idling and activated states. When we assess brain activation, it is common look at eyes-closed, eyes-open Baseline and task conditions.

Ordinarily we expect to see the brain with eye closed at rest, though not sleeping. In most cases this appears as a brain dominated by the Alpha frequency, especially in the rear. Read more… […]

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Our brains are essentially powerful systems for producing and distributing energy. Work done with computer programs that emulate neural networks has shown that they have a tendency to run away with themselves. It is the brain’s control circuits which allow it to focus on useful functions.

One of the measures of the EEG that helps to identify areas where training may be helpful is variability. Read more… […]

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Alpha Beta Symmetry

Now that we’ve looked at the different frequencies of brain activity and how they relate to the states of our experience, it’s time to begin talking about the location of these frequencies and what effect that has, especially on our moods.
We’ll look at symmetry within two major frequencies: Alpha, the resting awareness state; and Beta, the active processing state. We won’t be comparing Alpha vs. Beta. Rather we’ll compare Alpha in one area against Alpha in another and the same for Beta. Read more… […]

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Gamma is defined as a brain frequency ranging from about 25 Hz to 100 Hz or higher, though it is most strongly seen around 40 Hz. The discussion of Gamma and what it is and does has appeared fairly recently, since analog EEG readings don’t measure above 25 Hz. Even in the development of digital EEG, though Gamma had been identified in the 1960’s, the amplifiers used in recording EEG only registered into the low 30 Hz bands. As a result, Gamma is not included in most of the databases used today to determine what a “normal” EEG looks like. […]

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Stuck in a Frequency

So now we have looked at how each band of frequencies can affect what we do and how well. We’ve seen that fast and slow processing speeds and middle awareness frequencies each do certain things well and others not so well. Ideally, we understand that the brain has the ability to shift up and down the range, rest in the middle states and do all things at least fairly well.

Today we are going to talk about something other than the ideal… […]

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Middle Frequency Dominance

There is one middle frequency called Alpha that appears in all areas of the brain. Another, which only occurs in a specific area, is called Sensory-Motor Rhythm (SMR). Like slow frequencies, middle frequencies are broadcast by rhythm generators in the middle of the brain. Unlike the slow frequencies, which appear globally, middle frequencies are Regional. […]

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