Re: Re: daydreaming during neurofeedback sessions...

[Guest guest]

Kris,

HEG stands for Hemo EncephaloGraphy--training to increase blood levels and blood oxygenation, which improve the metabolic capacity of parts of the brain. It is primarily done on the pre-frontal cortex, the area behind the forehead, which is the executive center of the brain. One of the greatest benefits of HEG compared with EEG training is that it does not measure electrical signals. Training with EEG in the front of the head places the electrodes/sensors very close to the eye muscles, which produce large electrical signals when a client blinks or moves his/her eyes (muscles work with bio-electric signals just like the heart and brain). The EEG amplifier and/or software can't tell the difference between eyeblink signals and brain signals, so it includes these eyeblinks in the EEG we are training. It is called " artifact " because it is not really from the brain. It is difficult to avoid this eyeblink artifact when electrodes are placed hear the front of the head--and especially when they are on the forehead/prefrontal area.

HEG, since it measures blood perfusion or oxygen levels, is not affected by electrical activity, so you can blink as much as you wish and have no effect on the signal. Hence, for the many people who seek brain training who have a lot of slowing in their prefrontal areas, and thus have difficulty with planning, organizing, attention, impulse control or other executive functions, HEG can be a very helpful training approach. The more easily brain cells can get their blood supply, the more oxygen and glucose they have available to them, the faster they are able to fire when needed.

EEG has a fairly steep learning curve: there is a lot to learn about finding sites, placing electrodes to get a good signal, all the various different training options, performing assessments, etc. HEG is pretty simple to get started with, and it's hard to make many mistakes in working with it. So it can be an excellent place for a new trainer to start--or an excellent addition for an experienced EEG trainer.

There are two HEG systems available: pIR (stands for Passive InfraRed), developed by Jeff Carmen, and nIR (stands for near InfraRed), developed by Hershel Toomim. pIR measures the infrared temperature changes on the forehead (higher infrared temperatures indicate more metabolic activity) and is almost always done at Fpz in the center of the forehead. nIR measures the degree of red blood at the surface of the brain (indicating it is oxygenated) and it also measures infrard temperature changes. It is often used in 2 or 3 different sites in a single training session.

The main thing to remember when you do HEG is that oftentimes less is more. Over training--training too long--can stress the prefrontal area and result in headaches, agressive behavior, sleepiness, etc. Usually trainers start with around 10 minutes in a session and work up to around 30 minutes. There is some evidence that training once every 4 days is the optimum frequency for HEG>

You can find some HEG equipment at http://www.brain-trainer.com/equipment/ (look at Pocket A3 and Pendant-HEG).

Pete

What is HEG training?

.. -- Van Deusen

pvdtlc@...http://www.brain-trainer.com305/433-3160The Learning Curve, Inc.