In the general context of your question, "brain mapping" probably refers to the application of quantitative electroencephalography (qeeg; a type of brain-wave recording) to create pictures of brain activity for the purpose of providing biofeedback
. Another name for "brain mapping" is "neurofeedback."
here's an overview of how it is done: like regular eeg
, qeeg uses recording surfaces that are applied to the scalp to capture the electrical activity generated by the cerebral cortex. The signals, which are in the microvolt (one one-millionth of a volt) range, are electrically and digitally amplified. In a regular eeg, the signals are displayed on a screen to be reviewed by a physician with specialty training (often a neurologist specializing in epilepsy
). Good quality eegs contain about 2 dozen channels of information, displayed on the screen as squiggly lines. Each line corresponds to the activity of a region of cortex relative to another part of the brain or head. Interpretation of eeg is both an art and a science, and requires a high degree of training and experience.
In qeeg, after the signals are amplified, they are heavily digitally processed by software using something called fourier analysis. Basically, the processing breaks up each channel of information into ranges of frequencies. These ranges are usually described as sub-delta, delta, theta, alpha, beta, and supra-beta. After being heavily processed by computer graphics software, the predominant frequency of each brain region is displayed as a color on a computer-generated image of a brain or head. The images are designed by computer-graphics programmers to look very realistic, and are often rendered in virtual 3d.
In a qeeg neurofeedback session, the client is supposed to look at the colors and patterns shown on the monitor, and with the guidance of the provider, try to make the colors and patterns resemble those of a "normal" person.
I think it is fair to say that this application of "brain mapping" and neurofeedback is controversial. Some critics would call it peudoscience, and a few would have worse names.
One basic criticism is that since the brain is made up of 100 billion neurons, each channel of qeeg registers the average activity of about 4 billion neurons. That would be like asking the entire population of the earth a multiple-choice question, and saying that the average answer was accurate. Another criticism is that the areas of the brain that most contribute to the types of behaviors that qeeg clients are seeking to change are deep inside the brain, and therefore largely invisible to the recorders on the scalp.
A higher-level criticism of neurofeedback is that it is highly prone to the placebo
effect, and in fact may actually make use of the placebo effect by harnessing our sense of wonder in technology and our belief in computer-generated virtual reality.
Perhaps the most convincing criticism of neurofeedback is that it lacks any rigorous proof that it works, such as from placebo-controlled studies.
Because there is no proof of the effectiveness of neurofeedback or "brain mapping, " insurance
companies do not cover the sessions. A typical course of neurofeedback comprises 40 or so sessions, and last i checked, each session runs about $100.
Neurofeedback is one of a number of glamorous and attractive pseudo-scientific approaches to serious psychiatric and psychological problems that are often difficult to treat. Such approaches often appeal to patients or family members who are frustrated by conditions that seem hard to treat or incurable. Desperate people have long been the prey of those with a profit motive.
Risks of neurofeedback include both the out-of-pocket expense, and the risks that are incurred by diverting the client's attention and resources away from proven therapies.