HEG (hemoencephalography)-HEG measures blood flow in the frontal lobe of the brain. When that area is active, the body increases blood flow to that area to bring energy in the form of nutrients and oxygen to support the increased metabolic activity in that area’s brain cells. HEG biofeedback encourages activation of the frontal lobes and consequentially is able to effect stress that comes from under-activation of this area. Of the two types of HEG, pIR and nIR, pIR is offered at TetraNeuroNet. pIR uses a forehead sensor and measures a narrow band of the infrared spectrum that is correlated to activation of the brain’s metabolic processes. pIR gives a global impression of the blood flow within the brain.