Neuromodulation types

There are multiple kind of neuromodulation procedures. In the medical world, neuromodulation is a “non-invasive” procedure because it does not involve surgery or implanting electrodes. But there are forms of Biofeedback that do require sending some type of electrical signal into the brain to impact the brain’s electrical activity.

Learn more about the various invasive and non-invasive types of Neuromodulation.

non-invasive Neuromodulation patient at Sadar Psychological and Sports Center

What is “Truly” Non-Invasive Neuromodulation?

Truly non-invasive forms of neuromodulation for the brain involve some type of neurofeedback where the brain is given visual, auditory and/or tactile feedback about some form of its functioning (e.g. electrical activity, blood flow, etc.). The brain then uses this feedback to learn to change itself and to become better at self-regulation.

What are the various truly non-invasive types of neurofeedback?

Traditional Higher Frequency Training

Infra-Low (or Infra Slow) Frequency Training

Slow Cortical Potentials Training

HEG hemoencephalography-biofeedback

Traditional Higher Frequency Training


Involves training brain waves in the 1 to 40 Hz range.

This is the training that has been around the longest and has the most research supporting it. This is also the training that is best able to use the results of a qEEG analysis to guide protocol selection.

Most of this training, and most of the available research, has involved training with one channel, with sensors placed either referentially (that is with one sensor on the scalp) or sequentially (that is with two sensors on the scalp).

Certain frequency ranges are selected for training which means they are selected to be reinforced to increase or decrease their amplitude. Through the computer interface the client receives real time feedback about their brainwaves which enables them to change their brainwaves in the desired direction(s). Changing their brainwaves is akin to changing their brain’s electrical activity. By doing so, the person’s brain becomes better at self-regulation which allows for more efficient and optimal functioning.

There have been subsequent variations of this training that involve more than one channel being trained, training coherence rather than frequency amplitude, theoretically training sites within the brain rather than on the brain’s surface, etc.

To date, there is no research that has demonstrated the superiority of one approach over another, and all of these approaches involve training in the higher, 1-40 Hz, realm.

Infra-Low (or Infra Slow) Frequency Training

This is the training most often associated with the Othmers (Siegfried and Sue), but it is available using other equipment (e.g. Brainmaster).

This involves training of frequencies below .5 Hz and goes down into the millihertz range. These slow brain waves are thought to underlie the higher frequencies. The long wave length of these ultra-low frequencies makes them more difficult to detect and accurately measure, so there is controversy regarding what is really being measured by this approach.

Nonetheless, it is hard to deny the clinical outcomes that have been documented with this approach.

Some people who have not responded to higher frequency training have a positive response to ILF training, and vice versa.

ILF training does seem particularly helpful in calming a brain that is over activated or over aroused.

Slow Cortical Potentials Training

Slow Cortical Potentials Training is done primarily in Europe.

This training is aimed at training the shifts that occur in cortical electrical activity from negative to positive.

Negative SCPs are assumed to reflect lowered thresholds for the excitation of underlying neuronal structures, leading to facilitation of processing e.g., during states of behavioral or cognitive preparation.

Positive SCPs indicate reduction of cortical excitation of the underlying neural structures (e.g., during behavioral inhibition), resulting e.g., in an attenuated startle reflex.

Training increased control over these slow cortical potentials has been shown to enhance brain function and thereby have a positive effect on a variety of symptoms.

But again, this type of EEG-biofeedback is done mainly in Europe and is difficult to find in the USA.

HEG (hemoencephalography)-biofeedback

HEG (hemoencephalography)-biofeedback is also seen as a type of neurofeedback, but it involves monitoring blood flow in the brain, rather than electrical activity. HEG-biofeedback involves wearing an infra-red sensor over one’s forehead.

This allows for the reading and the feeding back of the amount of blood flow occurring in the regions of the prefrontal and frontal lobes.

Blood flow is an indication of the amount of metabolic activity. Increased metabolic activity reflects increased activity of the brain’s neurons. Consequently, by learning to increase blood low in the frontal and prefrontal regions one is seen as enhancing the functioning in these regions, which involve the so-called executive functions.

This type of training was initially developed to treat migraine headaches. It continues to be used for this purpose, but its’ use has expanded to help with many other issues (e.g. ADHD, anxiety, depression, etc.).

There ae two types of HEG-biofeedback: passive infra-red or PIR HEG, and near infra-red or NIR-HEG. They are both purported to have basically the same effects.

What different types of Neuromodulation (that include more than biofeedback)?

Biofeedback, such as EEG-biofeedback and HEG-biofeedback are totally noninvasive ways to impact brain regulation. There are other approaches to impact brain regulation which are under the umbrella of “neuromodulation”, and these basically involve sending some type of electrical or electrical magnetic signal into the brain to impact the brain’s electrical activity.

Some of these approaches have been labelled “biofeedback”, but they are technically not just biofeedback since they involve the imparting of some type of a signal into the brain rather than simply feeding back the brain’s activity to the client/patient.

They are also termed “non-invasive” in the general medical world because they do not involve surgery or implanting electrodes, but they obviously insert something into the brain, so they are not truly “non-invasive”. Examples of some of the more popular of these follow.

Note: There are those who argue that it is a good idea to get a brainwave analysis (e.g. qEEG) to help to guide the placement of the electrodes for rTMS or tDCS.

LENS (Low Intensity Neurofeedback System)

Reportedly works by disrupting the maladaptive patterns or looping mechanisms that the brain has acquired in response to acute conditions such as birth trauma, concussion resulting from a sports accident, addiction, anoxic event, etc.

The LENS encourages the brain, by introduction of a low intensity electrical signal, to release these inhibitive patterns, and adapt a higher functioning neural circuitry.

fMRI biofeedback

This involves placing the patient in a cylinder where a powerful electromagnetic field (about 50,000 times greater than the earth’s field) is used to read the oxygenation that is occurring in the patient’s brain.

This information is then fed back to the patient and they are asked to alter the level of oxygenation.

This does involve a biofeedback loop, but the information being fed back is generated through the flooding of the brain with an electromagnetic field.

PEMF (Pulsed Electromagnetic Field Therapy)

Initially used to facilitate healing in the body. This approach basically involves the induction of electricity into the cells to help stimulate or promote healing.

PEMF for neuromodulation involves using less powerful pulsed energy waves than are typically used to impact the body, but the basic principles are the same.

Neurofield is one of the more widely known neuromodulation approaches for the brain to utilize PEMF.

rTMS (repetitive Transcranial Magnetic Stimulation)

Is a form of is a form of brain stimulation in which a changing magnetic field is used to cause electric current at a specific area of the brain.

Effects vary based on frequency and intensity of the magnetic pulse as well as the length of the training, which affects the total number of pulses given.

This may also induce seizures in vulnerable people so it is a good idea to get an EEG before doing rTMS to rule out possible vulnerabilities (e.g. spikes, paroxysms).

tDCS (Transcranial Direct Current Stimulation)

Is a form or neuromodulation or neurostimulation. tCDS works by sending constant, low direct current through electrodes. The electrodes are placed in the region of interest and the current induces an electrical current flow in the brain. This current flow then either increases or decreases the neuronal activity in the specific area being stimulated based on which type of stimulation is being used.

This change of neuronal excitability leads to alteration of brain function, which can be used in various therapies. People with a seizure history should not do tDCS.

It is probably a good idea to get an EEG before doing tDCS to rule out the possibility of spike activity in the brain that is not causing actual seizures.

There is also the lesser used tACS, which uses alternating current rather than direct current.

How can Sadar Psychological Help me?

 The staff at Sadar Psychological have been in the truly non-invasive neuromodulation business since 1999, when we began to use EEG-biofeedback with our patients. We have remained in the field since and have recently begun to focus on functional EEG evaluations that can help to determine if and what form of neuromodulation might be most helpful for you, as well as, what types of lifestyle changes can have a positive effect on your brain function.

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