Theta

Theta is defined by some as 3-7 or 3-8 Hz and others as 4-8 Hz. Many more experienced trainers tend to prefer staying away from the Greek letter denominations and just talk about frequencies themselves.

3Hz activity is kind of a crossover point between delta and theta. It is a frequency which you generally will want to reduce. It is a very internal state, sometimes even a dissociative place, where contact with the environment is pretty minimal. It is also a frequency at which abreactions–re-experiencing of old traumatic material–takes place.

Theta in the 3-6 Hz range is more indicative of dissociation. In my experience abused children and women tend to have this low Theta that is difficult to differentiate from high Delta. If the client with high amplitude Delta in the 3-6 Hz range is alert and attentive, this is a good indication of low frequency Theta rather than high frequency Delta.

5Hz activity is still in the slow end of the theta range. It seems to be more related to cognitive issues, so you will often see lots of it in those who have learning problems, dyslexia, etc.

Getting up into higher theta, 7Hz theta is generally considered to be hippocampal theta. Its rhythm generator is the hippocampus, the brain’s main memory center. 7 Hz activity seems to show up when information is being put into or taken out of memory.  7Hz, hippocampal theta activates on the frontal midline (Fz to Cz) at task when memory is involved.  It’s not necessarily the same thing that one sees when a client has a lot of theta.

6-8 Hz theta seems to be the frequency that most relates to memory, visualization and access to the subconscious. That’s why we train for 7 Hz crossovers in alpha-theta training, which ideally takes the client as an observer to the entrance to his own subconscious mind.

7 Hz is seen in various areas around the brain, though especially in the frontal midline (around Fz) when memory processing is taking place. It is called “hippocampal” theta, because it is a rhythm produced in the hippocampus, the memory center inside the temporal lobes, and appears in the cortex.

7Hz is also a visualization frequency. I like to train that (either through alpha/theta or directly) in the parietal or occipital lobes to improve a client’s ability to visualize performance in advance of doing it, a kind of programming of the subconscious with the desired outcome.

7Hz is also the crossover frequency we aim for in alpha/theta training. At that frequency clients tend to have visual images of old memory material, but it takes place without the client actually re-experiencing or abreacting that material.

Source of Theta

I believe there are two sources for theta in the sub-cortical brain:  hippocampal theta, which is related to memory functions, is around 7 Hz.  Lower theta is cortical response to rhythms from another area of the thalamus from that which produces the alpha rhythm.

Theta’s “globality” is more related to the fact that it generally emanates from a single source wherever you find it. However, training it down in one place doesn’t necessarily have any global effect on theta amplitudes.  When you train down theta–as when you train down alpha–you are de-synchronizing specific pools of neurons from sub-cortical rhythm sections. This makes it easier for them to do specialized beta functions.  You are probably also pushing blood supply to those neurons–and not necessarily all neurons.

Theta is a visual frequency in general (or at least a non-language processing frequency), so any task, like watching a movie, playing a video game, taking something apart and remembering how to put it back together, etc. are done very well with slower frequencies.  The chances are that the high adrenaline content of many video games keeps the sleepy brains of ADHD kids awake, which is why they like them.  It’s like risk-taking behavior, which many ADHD’ers also engage in a great deal.

Training Theta

Training down thelta (delta/theta) in a very slow brain requires the brain to work harder than it is accustomed, so train for short segments (I often suggest 2 minutes) and take breaks between segments (1-2 minutes is usually fine).  Training up SMR, which is related to the ability to go from drowsy stage 1 sleep into stage 2, where you are actually asleep, often results in drowsiness early in training, though usually it doesn’t last long after a session.

More troublesome theta in the frontal lobes is usually found in the lower end of the frequency band (2-5 Hz), and it increases when the brain is trying to do a task, when it should be decreasing. And it is the relationship of theta to alpha and beta speeds more than the absolute amplitude of any one of them that is much more useful in determining if there is a problem worth training to achieve a specific behavioral/mood/performance outcome. If the relationship between alpha and theta is well below 1:1 with eyes closed, or if theta divided by beta is well above 2, then that may be worth training.

The combination of low theta/beta and high alpha/theta ratios most strongly suggests extremely low theta–perhaps especially in the 6-8 Hz band, but very possibly in low theta and delta also.  That points to what is very frequently the underlying picture of any somaticized pattern, a blockading of the subconscious.  Theta (and particularly 6-8 Hz) is the gateway to the subconscious.  Good levels of alpha provide a bridge across which subconscious material can reach the conscious and vice-versa.  Extremely high or low alpha/theta ratios indicate that this is not happening–either there is no bridge (low alpha) or a drawbridge stuck open (high alpha).

There’s probably not much written about getting into theta, since most neurofeedback is about getting OUT of it.  There’s no real problem to getting into it.  Just stare off into space and daydream, or close your eyes and let yourself drift toward sleep, and you’ll go into theta dominant states.  There’s a big difference between synchronous theta and asynchronous theta, which is a kind of spaced-out unfocused state.

Anything that moves a person into their head and out of contact with the environment will increase theta.  It’s like the sick dog syndrome.  The animal goes away and finds a place to hole up and let nature take its course.  We humans (if we don’t get sucked too far into the healthcare system) tend to do the same.  In a client’s case, if she’s “going away” the same as an ADD child does, by going into that internal, intuitive theta state, helping her to keep from getting “stuck” there is a perfectly appropriate and effective training goal.

Theta can be synchronous or asynchronous–the result of low metabolic activation.

Reading and Theta

Some people who use lots of slow activity actually read with theta. Since theta is an image-based processing speed and a person like that “makes a video” of what she is reading.  And, of course, will have a lot of trouble remembering details from what she read.