By Dr Ernesto Sholomo Korenman
HEG (Hemo-Encephalo-Graphy ) biofeedback is an effective and drugless treatment
for many neuropsychological conditions which involves the self-regulation of cortical activation.
HEG represents a simple and non-intrusive way for both: monitoring and training
cerebral function without the inconvenience of electrode preparation which other
neurofeedback methods generally require.
HEG has high compliance by clients and patients and the training can be delivered
with a help of entertaining and attractive feedback suitable for children and adults.
Physiological Basis
HEG devices measure and feed back changes correlated with blood flow dynamics
and cellular metabolism in localized parts of the brain cortex. These measurements
are closely correlated with brain activation due to a phenomenon called
“neurovascular coupling”. Briefly, blood carries all the nutrients and oxygen needed
to fuel neuronal activation and the localized delivery of blood supply to each part of
the cortex is closely linked to the particular metabolic requirements and the level of
neuronal activity in that region at every single moment.
The logic behind this biofeedback intervention is that repeatedly engaging in HEG
biofeedback, "exercises" the brain in a unique way which confers very promising and
long lasting neuro-behavioural benefits for the trainee. Special pre/post SPECT
(Single Positron Emission Computerized Tomography) imaging techniques has been
already used to verify that HEG biofeedback treatment promotes conspicuous blood
flow increases, (activation), below the treated areas.
History
State of the art HEG methodology is originally based on brain monitoring
technologies like nIR Spectrophotometry and Thermoscopy developed in the last 10-
15 years.
In 1994 Dr. Hershel Toomim developed his own nIR Spectrophotometer
methodology and subsequently was the first to show that that the monitored activity
can be self-regulated by biofeedback means. His early work on the application of nIR
HEG biofeedback in the treatment of ADD and ADHD and other neurobehavioral
conditions followed soon after that.
Slightly afterwards, Dr. Jeff Carmen started experimenting to build and test a device
to measure cerebrovascular activation using passive infrared technology in an attempt
to both monitor migraine activity and to train control over the associated abnormal
cerebrovascular behavior. In 1998 Dr Carmen formally reported success in the
treatment of migraine through pIR HEG biofeedback.
In the last five years other researchers and clinicians have joined this exciting area of
neurofeedback, (mainly in the USA). However, this technology is still considered to
be the newest modality addition to the central biofeedback practice and a therapeutic
tool with extremely promising future.