Biomedical Engineering Reference
In-Depth Information
Below 8 hertz, the brain sleeps and has hardly any awareness. The
deeper the sleep, the lower the general brain activity. In the early
morning, when one is getting up and at night while one is preparing
for sleep, the brain frequency varies from between 8 and 13 hertz. This
mode can also be reached in the daytime at relaxing moments in which
we feel safe. The brain manages to operate in this modus as long as
there is not too much activity needed. This is an optimal mode for
learning because the brain still has room for digesting and saving new
information. Because learning is one of the main purposes of a toolbox
meeting, this meeting can best be held in a relaxed atmosphere; the
meetings will then generate more learning and a better preparation for
the task.
Every activity level has its own brain frequency.
When the need for activity rises, the speed of communication
between brain cells increases. The main effect of higher brain speed is
that the brain can handle situations quickly and concentrate more
easily on a specific action. The brain actively gathers all relevant infor-
mation that is needed for a task. It makes plans, checks options,
chooses the optimal solution, and prepares for the execution of tasks.
An optimum frequency for being active and detecting risks is around
20 to 25 hertz. At this speed, we have the highest awareness and an
alertness that is still reasonably broad.
In a high activity mode, the possibilities to assimilate new knowl-
edge decrease. So if people are in a hurry, for example, because they
are in a tight time schedule, it is better to focus the toolbox meeting on
the necessary actions. More relaxed opportunities later will probably
be more suitable for learning.
With an increasing demand for action (for example, when we expe-
rience a serious threat), the general speed of the brain rises. The basic
brain sends orders to the stress system. Stress can be defined as the
preparation of body and brain to be ready to perform. Although stress
has a negative connotation these days, it originated as a mechanism to
survive. When a lion is trying to catch a zebra, the zebra probably has
more stress than the lion because the zebra is running for his life while
the lion is running for his meal. Within the stress system, the adrenal
