It
is well known that the brain is an electrochemical organ; researchers
have speculated that a fully functioning brain can generate as much
as 10 watts of electrical power. Other more conservative investigators
calculate that if all 10 billion interconnected nerve cells discharged
at one time that a single electrode placed on the human scalp would
record something like five millionths to 50 millionths of a volt.
If you had enough scalps hooked up you might be able to light a flashlight
bulb.
Even
though this electrical power is very limited, it does occur in very
specific ways that are characteristic of the human brain. Electrical
activity emanating from the brain is displayed in the form of brainwaves.
There are four categories of these brainwaves, ranging from the
most activity to the least activity. When the brain is aroused and
actively engaged in mental activities, it generates beta waves.
These beta waves are of relatively low amplitude, and are the fastest
of the four different brainwaves. The frequency of beta waves ranges
from 15 to 40 cycles a second. Beta waves are characteristics of
a strongly engaged mind. A person in active conversation would be
in beta. A debater would be in high beta. A person making a speech,
or a teacher, or a talk show host would all be in beta when they
are engaged in their work.
The
Brainwaves
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The
next brainwave category in order of frequency is alpha. Where beta
represented arousal, alpha represents non-arousal. Alpha brainwaves
are slower, and higher in amplitude. Their frequency ranges from
9 to 14 cycles per second. A person who has completed a task and
sits down to rest is often in an alpha state. A person who takes
time out to reflect or meditate is usually in an alpha state. A
person who takes a break from a conference and walks in the garden
is often in an alpha state.
The
next state, theta brainwaves, are typically of even greater amplitude
and slower frequency. This frequency range is normally between 5
and 8 cycles a second. A person who has taken time off from a task
and begins to daydream is often in a theta brainwave state. A person
who is driving on a freeway, and discovers that they can't recall
the last five miles, is often in a theta state--induced by the process
of freeway driving. The repetitious nature of that form of driving
compared to a country road would differentiate a theta state and
a beta state in order to perform the driving task safely.
Individuals
who do a lot of freeway driving often get good ideas during those
periods when they are in theta. Individuals who run outdoors often
are in the state of mental relaxation that is slower than alpha
and when in theta, they are prone to a flow of ideas. This can also
occur in the shower or tub or even while shaving or brushing your
hair. It is a state where tasks become so automatic that you can
mentally disengage from them. The ideation that can take place during
the theta state is often free flow and occurs without censorship
or guilt. It is typically a very positive mental state.
The
final brainwave state is delta. Here the brainwaves are of the greatest
amplitude and slowest frequency. They typically center around a
range of 1.5 to 4 cycles per second. They never go down to zero
because that would mean that you were brain dead. But, deep dreamless
sleep would take you down to the lowest frequency. Typically, 2
to 3 cycles a second.
When
we go to bed and read for a few minutes before attempting sleep,
we are likely to be in low beta. When we put the book down, turn
off the lights and close our eyes, our brainwaves will descend from
beta, to alpha, to theta and finally, when we fall asleep, to delta.
It
is a well known fact that humans dream in 90 minute cycles. When
the delta brainwave frequencies increase into the frequency of theta
brainwaves, active dreaming takes place and often becomes more experiential
to the person. Typically, when this occurs there is rapid eye movement,
which is characteristic of active dreaming. This is called REM,
and is a well known phenomenon.
When
an individual awakes from a deep sleep in preparation for getting
up, their brainwave frequencies will increase through the different
specific stages of brainwave activity. That is, they will increase
from delta to theta and then to alpha and finally, when the alarm
goes off, into beta. If that individual hits the snooze alarm button
they will drop in frequency to a non-aroused state, or even into
theta, or sometimes fall back to sleep in delta. During this awakening
cycle it is possible for individuals to stay in the theta state
for an extended period of say, five to 15 minutes--which would allow
them to have a free flow of ideas about yesterday's events or to
contemplate the activities of the forthcoming day. This time can
be an extremely productive and can be a period of very meaningful
and creative mental activity.
In
summary, there are four brainwave states that range from the high
amplitude, low frequency delta to the low amplitude, high frequency
beta. These brainwave states range from deep dreamless sleep to
high arousal. The same four brainwave states are common to the human
species. Men, women and children of all ages experience the same
characteristic brainwaves. They are consistent across cultures and
country boundaries.
Research
has shown that although one brainwave state may predominate at any
given time, depending on the activity level of the individual, the
remaining three brain states are present in the mix of brainwaves
at all times. In other words, while somebody is an aroused state
and exhibiting a beta brainwave pattern, there also exists in that
person's brain a component of alpha, theta and delta, even though
these may be present only at the trace level.
It
has been my personal experience that knowledge of brainwave states
enhances a person's ability to make use of the specialized characteristics
of those states: these include being mentally productive across
a wide range of activities, such as being intensely focused, relaxed,
creative and in restful sleep.
© 2000 Courtesy of Intelegen Inc. All rights reserved
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