| You most likely already know that brainwave | | | | relaxed, and are associated with associative thinking - |
| frequencies are grouped together into bands: delta, | | | | daydreaming, for instance - and the imagination. Closing |
| theta, alpha, beta and gamma. | | | | the eyes (whilst awake) causes an instant surge of |
| Although boundary states between these bands exist, | | | | alpha activity. |
| in this article I will focus on these five groups of | | | | Beta Waves |
| brainwave frequencies and describe the mental states | | | | Brainwaves between 12 and 30hz are classed as |
| and functions associated with each group. | | | | beta waves, and appear when an individual is alert and |
| The 5 brainwave frequencies are: | | | | focused. They are associated with concentration, |
| Delta Waves | | | | "busy thinking" and general movement. Alpha and beta |
| Brainwaves of a 4hz frequency or less are classed | | | | waves together make up the brainwave frequencies |
| as delta waves. These are associated with deep | | | | which appear when an individual is awake. Alpha |
| sleep, and are thought to be generated by the | | | | dominates when an individual is in a state of relaxation, |
| thalamus (a part of the brain that integrates information | | | | and beta when an individual is in a state of alertness. |
| from the different senses, and use it to direct | | | | Gamma Waves |
| attention). Most of a baby's brain activity is in the delta | | | | Brainwaves of a 40hz frequency or above are |
| range, but by adulthood delta waves are no longer | | | | classed as gamma waves. Flashes of sudden insight |
| present when a person is awake. | | | | or understanding ("a-ha" moments) are associated with |
| Theta Waves | | | | sudden surges of gamma activity. High gamma wave |
| Brainwaves between 4 and 7hz are classed as theta | | | | activity is associated with above average intelligence, |
| waves. These are associated with REM (rapid eye | | | | and children with high gamma activity have been found |
| movement) sleep, during which dreaming occurs. They | | | | to have higher than average language abilities, cognitive |
| are generated by the hippocampus, which is a part of | | | | skills and attention spans. |
| the brain responsible for forming memories. They also | | | | Experiments on Tibetan Buddhist monks have shown |
| appear during meditation. Delta and theta waves | | | | that long term meditation causes an overall increase in |
| together make up the brainwave frequencies which | | | | gamma wave activity - perhaps as a consequence of |
| appear during sleep. | | | | techniques which stress concentration and focus. In |
| Alpha Waves | | | | fact, there are many correspondences between |
| Brainwaves between 8 and 12hz are classed as alpha | | | | meditative states and brainwave frequencies. |
| waves. Alpha waves appear when an individual is | | | | However, those are to be covered in another article. |