The frequency of human brain waves has a range of 0.5 – 70 Hz with various amplitudes and symmetry. Equilibrium between the waves in right and left brain (inter-hemispherical symmetry) is also an important factor. Natural brain frequencies are designated as alpha: 8-12 Hz; beta, 12-30; theta: 4.0-8.0 Hz; delta: 0.5-4.0 Hz, and gamma: 30 Hz and above.
Normal frequencies of the human brain associated states are shown below. These frequencies can be picked up by an EEG (Electroencephalogram) from the surface of the brain, after their amplification, as they are in the range of micro-volts. A mixture of these frequencies is present at any given time. Quantitative Electroencephalography (QEEG) is an extension of the analysis of the visual EEG interpretation which may assist and even augment our understanding of the EEG and brain function. QEEG is a procedure that processes the recorded EEG activity from a multi-electrode recording using a computer and converts it into a brain map showing different brain waves.
Normal Brain Waves
QEEG Brain Mapping
EEG and QEEG Brain Mapping
There are several conditions that can lead to brain wave abnormalities:
Scientific literature over the recent years have been increasingly able to associate these abnormalities of the brain waves with growing number of conditions. Even to the extent that most recent literature have been able to use these brain wave abnormalities as biomarkers for certain conditions.
For example: Brain Waves
When certain areas of brain are in an over-arousal state, individual can experience:
Under-arousal of the brain is related to:
Unstable brain waves are seen in:
Neurofeedback can change the desirable brain activity in those who are experiencing symptoms of certain mental health conditions.
EEG Frequency Bands in Psychiatric Disorders: A Review of Resting State Studies
Shows differences in frequency bands across a spectrum of psychiatric disorders including:
Dominant results for each individual disorder and band. (A) Differences in absolute power for each disorder (relative to control) for eyes closed condition (top), eyes open (middle) and eyes open and closed combined (bottom). White boxes indicate no change, black indicates an increase, and gray indicates a decrease. Opposing results are shown by hashed boxes. (B) Difference in results between absolute power and relative power for the same disorders. White indicates no difference, gray indicates a significant increase or decrease in one but no significant difference in the other, while a hashed box indicates opposite results.
Changes of the brain’s bioelectrical activity in cognition, consciousness, and some mental disorders
Shows that slow brain waves are seen in conditions such as:
While rapid waves are generally reported in conditions like:
QEEG Brain Mapping changes in ADHD (Attention Deficit Hyperactivity Disorder)
QEEG Brain Mapping changes OCD (Obsessive Compulsive Disorder)
QEEG Brain Mapping comparison in ADHD, Depression, Anxiety and Migraine
Unsurprisingly, association of these brain wave abnormalities has led to intervention procedures where, through neurofeedback and other methods, the brain is coaxed to bring the abnormal frequencies to the normative state and thereby trying to correct the symptoms associated with specific conditions. These modalities have been very helpful in many conditions to the extent that the dose of pharmacological agents used for certain condition can be reduced, thus minimizing the associated side-effects.
Pulsed Electromagnetic Field (PEMF) therapy is one such example, where, by application of very mild electromagnetic pulses in desired frequency band, many conditions can be improved without any harm to the patient. Today the technology has reach to a point where this can be achieved by a wearable device that can be used anywhere and anytime. This is the era of wearable neuro-tech. It has benefited many persons and that too at a nominal cost. This type of therapy is becoming increasingly beneficial and convenient with each passing day. These can be used in combination, as home-therapy, with neurofeedback or used as a stand-alone device.
Anxiety - QEEG before and after Neurofeedback/PEMF
Depression - QEEG before and after Neurofeedback/PEMF
ADHD - QEEG before and after Neurofeedback/PEMF
»It always seems impossible until it is done.« (Nelson Mandela)