What are the types of brain waves?

There are four different types of brain waves. They are all designated Greek names, and they are referred to as beta waves, alpha waves, theta waves and delta waves. Each of the brain waves represents a different state of consciousness.

How are brain waves measured? 

Pic: http://www.popsci.com.au/technology/use-your-body-s-electrical-field-to-uniquely-identify-yourself/eeg-head20120808071538.jpg

The method with which brain waves can be measured is with an electroencephalogram, otherwise known as an EEG. The picture above shows how electrodes are placed on your brain when an EEG is being conducted. The basic rule when reading an EEG is as follows: the more closely spaced the waves are, the faster the electrical signals are being sent through the brain. The faster the rate of electrical signal, the higher your state of consciousness you are in. Brain waves are measured in units called hertz (Hz); this measurement is also used when determining radio frequencies, with AM stations being measured in kilohertz (kHz), which is equal to a thousand Hz, and FM stations in

megahertz (MHz), which is equal to a thousand kHz or 1 million Hz.

Beta Waves (14-30Hz)

Pic: http://www.hypnosisweblibrary.com/images/brainwaves.jpg

Awake or Asleep? Awake

This is often recognized as the highest state of consciousness. There is another type of wave known as gamma waves, but they are often placed under the category of beta waves instead.  This particular type of brain wave is associated with a state of great alertness, stress and concentration, and is often noted in the following circumstances:

  • The classic ‘fight, fright or flight’ response, where adrenaline is pumping through your body
  • High states of anxiousness, such as just before going on stage or public speaking
  • Certain diseases

Alpha Waves (8-13.9Hz) 

Awake or Asleep? Awake

This state is usually seen within a person who is conscious (awake), however, with this particular frequency of brain wave, they tend to be in a more relaxed and focused state. Serotonin levels tend to be increased when the brain is in this state. Alpha waves can be seen in the following circumstances:

  • When you are studying for something and in a deep state of focus
  • When you are in a light trance or at the beginning stages of meditation
  • When you are reading a book
  • When you are writing an essay or an article on something

Interestingly, contrary to popular belief, neural studies have shown that listening to music that you like increases your brain’s capacity to work whilst you are performing the above tasks. It doesn’t matter if it’s classical or heavy metal: your music taste is the deciding factor, not the tempo of the music. Anything’s better than just studying in silence in my humble opinion: from personal experience, it keeps one part of my brain distracted whilst I am working, plus it makes the experience more enjoyable.

Additionally, alpha waves can be seen in people who are tossing between a state of consciousness and subconsciousness (being awake and asleep): the alpha waves become longer (closer to 8Hz) when this happens. Examples of this include the following:

  • Watching TV or reading and you drift off due to drowsiness
  • Turning your lights off to go to sleep and you first close your eyes
  • Being in a deep meditative state
  • Gaining access to your subconscious i.e. through hypnosis

Theta Waves (4-7.9Hz)

Pic: http://images.forwallpaper.com/files/images/9/9547/95477e8f/153467/garfield-garfield-cat-sleeping-sleeping.jpg

Awake or Asleep? Asleep

Theta waves are waves seen when someone is in a shallow state of sleep.  This is often seen when taking a power nap like Garfield is having alongside: you don’t have enough time to enter delta-wave sleep and you rotate between theta and alpha waves. Theta wave patterns are seen in three points of sleep:

  • When you first fall asleep
  • Just before you wake up
  • REM (rapid eye movement) sleep: this is the wave responsible for you being capable of dreaming

This stage of sleep is responsible for being able to us to retain new information (very important, particularly if you’re cramming for an exam!) as well as retaining what we have learnt the previous day and the emotional experiences we had.

Delta Waves (0.1-3.9Hz)

Smart Art Graphic: Original
Smart Art Graphic: Original

Awake or Asleep? Asleep

Delta waves are seen when someone is in a deep state of subconsciousness. Unlike theta-wave sleep, delta wave sleep is dreamless in nature. When you fall asleep at night (or during the day if you work overnight shifts), you rotate several times between theta wave patterns and delta wave patterns, as demonstrated by the Smart Art Graphic alongside. When you are in deep sleep, hormones from the pituitary gland are released and get to work on the body. Examples of such hormones are prolactin and human growth hormone.