2.9 Alpha Waves: Definition & Concept

Jan 18, 2020 | ch2 Biological Bases of Behaviour, Courses, Intro to Psychology

Did you know that your brain produces electrical impulses that create brain waves? In this lesson, you will learn about the first brain waves to be discovered, how they are produced, measured and why they are significant today.

The Discovery of Alpha Waves

Your brain is made up of billions of cells called neurons, which are constantly firing information back and forth between one another while receiving and sending messages. For example, when you are reading a book, your brain is receiving information through your eyes, processing the words you are reading and applying meaning to them.

All of these signals are electrically sparking between one another in a certain pattern and these electrical patterns create brain waves. These waves are so small that they can only be recorded in a lab and reproduced through an the electroencephalogram (EEG) or magnetoencephalogram (MEG) machine.

Just like different types of music (rock vs. classical) create different sound waves, these electrical signals also create distinct waves or oscillations. Depending on what you are doing (i.e. reading), only certain parts of your brain are activated, which produces different types of brain waves, as you can see in the chart below.

Different Brain Waves (EEG)

These different brain waves each serve different purposes:

  • Gamma waves are associated with problem solving and deep concentration
  • Beta waves takes place when one is active and busy, stressed
  • Alpha waves, which are the focus of this lesson, happen in a reflective and relaxed state
  • Theta waves occur right before going into a deep sleep (drowsiness)
  • Delta waves are present while one is fully asleep/dreaming

The first brain waves to be recorded through EEG were recorded in 1929 by neurologist Hans Berger. Since, it was the first brain waves he discovered, Berger named these events as the ‘waves of the first order’ or as we know them today Alpha waves. They were recorded on his human subjects while they were awake, sitting with their eyes closed and are associated with creativity and clear thinking processes. This electrical activity produced 10 waves per second or 10Hz, giving off the strongest EEG brain signals through the occipital lobe (the back part of the brain).

 

Hans Berger
First EEG Scalp Recordings

Alpha Waves: Location and Frequency

Since Berger’s initial findings, studies on humans, dogs, cats, and rats have concluded that the thalamus (relays motor and sensory signals to the rest of the brain) has a clear role on generating alpha waves. However, they show up to be the strongest and are best measured through the occipital lobe.

Alpha waves have a frequency band of 8-13Hz and although they are present since birth as your brain is developing, the earliest they are detected is at 4 months old. They do not mature (10 waves per second) until the age of three, reaching maximum frequency (13 waves per second) in adolescence, and begin to gradually decrease after young adulthood.

Alpha waves produced in Occipital Lobe (Brain)

 

Deficiency in Alpha Waves and Mental Disorders

Researchers believe that the chronic decrease of Alpha waves during ongoing wakefulness in our adulthood into old age characterizes the onset of neurological and psychiatric disorders. Today many doctors look for a deficiency in the production of Alpha waves as markers to diagnose various mental disorders, such as depression, alcoholism, Parkinson’s, and Alzheimer’s.

Current studies are now focusing on practicing meditation and how this positively affects Alpha waves by relieving symptoms of depression and slowing the progression of other mental diseases. Other studies have shown certain amino acids (found in tea) to also stimulate alpha brain waves to enhance creativity, focus, and multitasking while one is actively reading or studying, and some claim that certain types of music (i.e. classical, coffeehouse) can also have a positive affect on Alpha waves.

Lesson Summary

The first brain waves to be discovered were in 1929, through an electroencephalogram (EEG), by neurologist Hans Berger. These waves, Alpha waves, are easily readable and found to radiate from electrical activity that takes place in the Occipital Lobe. Alpha waves are slow, high in amplitude and have a frequency band of 8-13Hz. They mainly occur while one is in an awake but relaxed state, such as sitting with your eyes closed or during an activity such as reading. Current studies have shown an increase interest in the production of Alpha waves and their relationship to mental health.

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