EEG (Electroencephalography) measures brainwaves at different frequencies. Electrodes are placed on specific areas of the skin to measure and record the electrical activity in the brain.

Frequency is the number of times a wave repeats in one second.

You can compare it to the frequency when you change stations on your radio. When these frequencies are insufficient, excessive, or difficult to find, our mental performance may suffer.

Amplitude represents the strength of the electrical activity produced by the brain.

The volume or intensity of brainwave activity is measured in microvolts.

Raw EEG is mostly defined by frequency bands. Gamma, alpha-beta-SMR-delta-theta waves are present in our brain.

Brainwaves are low-frequency electrical activity created by neurochemical activity in the living brain.

Scientists have defined brainwaves under five main headings.

​

GAMMA (greater than 30 Hz),

BETA (13-30 Hz),

ALPHA (8-12 Hz),

THETA (4-8 Hz) AND DELTA (less than 4 Hz)

Delta (0.1-3 Hz)

​

For example: Our brain uses 13 Hz (high alpha and low beta) for "effective" intelligence.

Often, individuals with learning disabilities and attention problems show a deficiency in 13 Hz activity in certain brain regions, affecting their ability to perform sequential tasks and mathematical calculations.

 

BRAIN WAVE FREQUENCIES

​

Delta (0.1-3 Hz)

 

The lowest frequencies are delta. It is below 4 Hz and is seen in deep sleep, and in some abnormal processes, delta waves reflect subconscious thoughts when an "empathy state" is felt. In infants up to 1 year old, it is the dominant rhythm and is found in stages 3 and 4 of sleep.

Amplitude is the highest and slowest wave. We increase delta waves to reduce our awareness of the physical world. We also access our subconscious thoughts through delta waves.

Those who want to improve performance reduce delta waves, achieving high focus and peak performance.

However, individuals diagnosed with Attention Deficit Disorder increase delta waves instead of decreasing them when trying to focus. Inappropriate delta waves severely restrict focus and attention. It's as if the brain is constantly locked into a sleepy state.

To define delta waves from another perspective; imagine you are driving a car in first gear. You can't go very fast in this gear. So, delta represents first gear.

 

• Theta waves: (5-7 cycles per second), slow brain waves, seen during daydreaming, twilight, and deep relaxation. This wave disrupts attention and concentration, and can induce daydreaming.

• Alpha waves: (8-12 cycles per second), brain waves seen in states of conscious relaxation.

• SMR (Sensorimotor rhythm) waves: (12-15 cycles per second), brain waves seen during focused activity.

• Gamma waves: Measured between 36-44 Hz, this is a single frequency band group found throughout the brain.

 

If we see the sleep wave delta and the dreaming wave theta in a QEEG data bank recorded while awake, or if we don't see Alpha, SMR, and Beta waves in the regions where they should be, we can teach the patient/person to lower or raise these waves in various regions of the brain using Neurofeedback therapy.