HEG Hemoencephalography - Neurofeedback with Infrared Sensors

Hemoencephalography (Greek haima = blood, ancient Greek enkephalos = brain, Greek graphe = writing) refers to a method of neurofeedback in which the brain activity is measured not with the help of an EEG, but with so-called near-infrared spectroscopy.

The physiological basis of the HEG

For hemoencephalography (HEG), the metabolic activity, the so-called metabolic rate in the respective brain areas is of interest. In fact, this concept is widely used in the field of imaging in modern brain research. Metabolism is a cellular process in which "fuel" in the form of glucose or sugar is "burned" to release energy, which in turn can be used by the cell. This process consumes oxygen and carbon and generates carbon dioxide. The metabolic conversion corresponds to the amount of energy consumed.
When the brain is mentally active, such as in mental arithmetic, we expect that the regions of the brain directly involved in the task consume more energy and thus achieve a higher and faster metabolic rate than other brain regions.
The human brain has an extremely active metabolism. Although the brain accounts for only 2% of body weight, oxygen consumption is 20% and glucose consumption is 25% of total consumption.

The application of HEG

As with fMRI, HEG also recognizes changes in brain activity by measuring fluctuations in blood oxygen levels.
This form of neurofeedback does not require electrodes in the conventional sense and is therefore much easier to use. Artifacts such as sweat or winking are, unlike the classic EEG, nearly impossible. The feedback process is based on a data analysis of the infrared sensors in the area of the forehead. The frontal lobe, which is usually considered the most active brain area, plays a particularly important role in attention and concentration. Some disorders, such as migraine, often have their cause in this area. HEG has also been established in the treatment of autism and Asperger. In a HEG session, the subject learns to improve the blood flow in prefrontal areas, which is usually associated with a significant improvement in symptoms.