Descriptions of Biofeedback Modalities
The most common biofeedback modalities are EMG (Electromyography), SCR (skin conductance response and temperature response), and sweat gland activity. But there are more particular procedures emerging like EEG (electroencephalograph or neurotherapy), HRV (heart rate variability) , and BVPI (blood volume pulse). We already covered the three “workhorses” of biofeedback (EMG, SCR, and sweat gland activity) in previous posts. Lets move on to the more specialized forms of biofeedback.
EEG or Electroencephalograph Biofeedback or Neurotherapy
I hope I am not getting to technical with that but I need to mention some terms in order to make this concept understandable, or show why it works. Brain activity, like most other functions of the body, can be monitored. What is measured is the electric activity between the synapses of neurons. (look for future posts under the heading psychoneuroimmunology for a detailed explanation how this works.) This activity shows the exchange of information between pre- and post-synaptic space. It is termed post-synaptic potential (PSP). The tally of the PSPs is the EEG.
EEG is separated into different incidence of bands. Each incidence of band has a matching behavior. The biggest application of EEG is being the treatment of attention deficit disorder (ADD). Here is a case study:
Diagnosed with ADHD, inattentive type.
Children with this diagnosis have different brain-wave activity then kids who do not have this problem. ADD and ADHD patients have normally excessive slow brain-wave activity or THETA, which causes them not to pay attention. In addition, they have not enough fast brain wave activity termed BETA. Stimulant medication gets these kids hyped up, with all kinds of side effects. Below, this case study will show how the same result is achieved without medication, and of course the nasty side effects.
After observing Jacks brain wave activity during various conditions simulating the school environment it was found that Jack had a ratio of approximately 3:2. The treatment sought to reduce this ratio to 1:1.
After being “hooked up” to the equipment, Jack was asked to increase beta waves and reduce theta without instrumentation. The thresholds were set so that Jack received a “point” 80% (eighty-percent) of the time. As Jack improved, thresholds were set to a more difficult level, hence shaping his response.
In addition to his task, he was asked to listen to, and read different types of material, to again, simulate school conditions. At first lessons lasted 20 to 25 minutes, however as Jack gained more control over his EEG, sessions sometimes exceeded one hour.
Interestingly enough, at the time Jacks parents reported unbelievable changes in his behavior, this time could be exactly pinpointed on the EEG and it’s first occurrence of Jack’s beta waves being higher than his theta waves. His parents reported that Jack had maintained his ability to concentrate following the treatment. Several months after treatment Jack was still able to produce the desired response and was doing very well in school.
I hope this will shed some light on the fact that there are other, more suitable modalities, then mere medication for problems like ADD and ADHD.
If you would like to start a dialog about this or any other topics feel free to click on the comment link below this article. Your comments are always welcome.
Tomorrow: Electrocardiology and HRV (heart rate variability) Biofeedback
(1) Complemetary & Alternative Medicine, A Research Based Approach. (2004) Mosby, St. Louis, Missouri, p. 220