Monday, January 24, 2011

EEG Brain Mapping

An important assessment tool is an EEG brain map. It helps gives us a snapshot picture of what’s going on in the brain. There are many types of brain maps – including MRI’s, PET scans, and SPECT scans. But the EEG map provides the best information for neurofeedback training. It shows brain timing issues which impact mood, behavior, and attention.  It measures cortical timing.  

The EEG patterns from an individual is compare with a "normative database" of other individual EEGs.  These "databases" compare the individual's EEG pattern with a group of carefully selected normal healthy people in a similar age group.  They were tested earlier.  

The qEEG report help identify where significant differences exist between the person being tested and the group.  There are hundreds, even thousands of measurements.  Much like a blood test, the clinician must know how to interpret the test results, including which are significant and relate to the clients problems.  An EEG brain map helps identify where the brain has specific problems – and helps target the kind of interventions. This information is sometimes used to help suggest appropriate medications. For neurofeedback, it provides a guide to where to train. Each area of the brain plays an important role. If one or more areas of the brain is running too slowly or too fast, it causes problems – such as attention, emotional control, mood, or behavior. 

Another measure is called coherence.  In very simple terms, coherence measures of how well coordinated the communication is between one area of the brain and another.  There is constant communication between different areas of the brain.  If two areas are not communicating well (too little or too much), it can interfere with the efficiency of the brain.  A qEEG brain map is one of the few tools that help assess coherence.  More research and a growing body of clinician experience suggests training coherence with neurofeedback may be an important component in an efficient brain. 

There is a growing number of clinicians using qEEG brain mapping.  There is disagreement in the field about qEEGs.  Some individuals teaching neurofeedback have at times said that qEEG mapping isn't necessary - and that there are other ways to get good results.  There are also many clinicians who find the qEEG very technical and with a steep learning curve.  They use other models for training the brain.  We don't have time to discuss those approaches here.  Many researchers feel that the qEEG represents evidence based medicine, and is on the cutting edge in neurofeedback. 

Very simple EXAMPLE of a qEEG map:


See the red in the middle of the 3 heads? That’s an indication of excessive amounts of slow activity (6-9 hz ). With eyes open, there should be very little if any red showing up. When your brain is making excessive slow activity, it can’t pay attention as well. Based on the map, we can train him to reduce that activity and increase his attention.

The EEG map above is from a 23-year-old boy who struggles with attention. People say to him all the time he doesn’t listen, even though he tries very hard. The red spots in this EEG map often are connected with problems with attention. In this case, when he tries to focus, his brain actually slows down – and is unable to sustain sufficient attention. He is being trained to reduce this slower activity and increase activity related to improved attention.

Depression qEEG example

The two brain map images below are from different people. The map on the left is from a person with a long history of depression. On the left, there is colored orange and yellow area. It represents an excess amount of slow brainwave activity. This pattern is often associated with depression. The picture on the right displays a relatively normal brain, without depression.

EEG’s are commonly used by neurologists to determine the presence of seizures, arteriovenous mal-formations and stroke. They look primarily for pathology. New applications by psychiatrists and psychologists use a digital analysis of the EEG for different purposes. Statistical analysis of the EEG can compare your brain activity to a large sample of an age specific normal population. This analysis can help identify problems that relate to cognitive and executive function, mood, anxiety and attention.

In psychiatry, EEG brain mapping has been of value in identifying disorders of biological origin, such as schizophrenia, dementias, hyperactivity and depression, brain atrophy and attention deficit disorders in children. Much of the pioneering work in psychiatry using EEG brain mapping has occurred at the New York University Brain Labs. The Brain Research Laboratories (BRL) is a division of the Department of Psychiatry at New York University School of Medicine under the direction of Drs. E. Roy John and Leslie S. Prichep. Drs. John and Prichep are also Research Scientists at the Nathan S. Kline Institute for Psychiatric Research.  There is a growing body of EEG brain mapping research, literature and normative databases around the world. 

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