Motor-skill memory tells people how to
do physical things that they have done
before. It can be short-term or longterm.
People use motor-skill memory to
copy a dance step and to ride a bicycle.
Factual memory is the storage of facts. It
can be short-term or long-term. Factual
memory lets people remember faces,
numbers, and the experiences that happen
to them.
Emotional memory is the memory of
emotions. It is long-term. For example,
people tend to remember very frightening
experiences throughout their lives.
Some scientists think this happens so
Looking at family photographs can bring
back happy memories.
Some people
can memorize
what an object
looks like after
only a glance.
This is called
having a
photographic
memory.
98 Memory BRITANNICA STUDENT ENCYCLOPEDIA
that people are prepared for problems in
the future.
Remembering
People can pull out information stored
in memory through either recall or recognition.
Recall means that someone
can remember something learned earlier.
Recognition is the ability to identify
something that has been seen or experienced
before. Recognition is easier than
recall. It may be easy to recognize a person’s
face, but it is more difficult to
recall the person’s name.
Patterns are also easier to remember than
random information. For example, it is
easier to remember a poem that rhymes
than one that does not.
Forgetting
Being unable to remember things is
called forgetting. A major reason for
forgetting is the passage of time. People
also tend to forget things that they do
not practice or review. Sometimes a disease
or an injury to the brain can cause
people to forget.
In general, people do not like to forget.
But forgetting serves some important
purposes. The brain forgets information
that it no longer needs. Then it may be
open to learning new information. Forgetting
can also help people to survive
painful experiences.
#More to explore
Brain
Meningitis
Meningitis is a disease that involves the
membranes, or thin coverings, around
the brain and the spine. Meningitis is
the inflammation, or swelling, of these
membranes. Germs called viruses and
bacteria can cause meningitis.
Common symptoms of meningitis are a
high fever, a headache, and a stiff neck.
People with meningitis also may be tired
and have a rash.
Viral meningitis, or meningitis caused
by a virus, is usually mild. It often goes
away without medical treatment. Bacterial
meningitis, or meningitis caused by
bacteria, is usually very serious. If not
treated right away, bacterial meningitis
can cause brain damage, deafness, or
death.
The viruses and bacteria that cause meningitis
spread easily between people.
They can be passed through touching,
coughing, or kissing. However, not
everyone in contact with the viruses or
Learning to ride a bicycle involves remembering
the movements needed to balance,
steer, and pedal.
The loss of the
ability to
remember is
called
amnesia.
Amnesia is
usually caused
by injury or
disease.
BRITANNICA STUDENT ENCYCLOPEDIA Meningitis 99
bacteria gets meningitis. Young children
and people who are already sick are
more likely to get the disease.
There are vaccines, or shots, that can
prevent bacterial meningitis. Frequent
hand washing also can help to prevent
infection by the viruses and bacteria that
cause meningitis.
If a person has meningitis, doctors need
to find out the cause. They do this by
taking fluid from the spine and testing
it. People with bacterial meningitis
receive a medicine called an antibiotic.
With quick treatment, they usually
recover. Most people with viral meningitis
just need to rest. After several days,
they usually feel better.
#More to explore
Bacteria • Disease, Human • Vaccine
• Virus
Mental Illness
When people have a mental illness, or
disorder, they cannot control certain
feelings, thoughts, or actions. Those
unusual feelings, thoughts, or actions
often cause problems in their daily life.
Some mental disorders are mild and
may go away on their own. Others are
serious illnesses that require medical
treatment.
Types of Mental Illness
Anxiety Disorders
People with anxiety disorders often
become afraid, even in safe situations.
They may feel helpless, dizzy, or short
of breath. Sometimes the fear happens
for no reason. In other cases the fear is
due to a specific thing—for example,
heights, crowds, or closed spaces.
Anxiety about a specific thing is called a
phobia.
Psychotic Disorders
People with psychotic disorders confuse
real life with fantasy. They may see or
hear things that are not there. They may
believe that they are someone else.
Schizophrenia is an example of a psychotic
disorder. People with schizophrenia
do not react in usual ways to
conversations or events.
Mood Disorders
People with mood disorders suffer from
depression (extreme sadness) or mania
(extreme excitement).With depression,
people feel sad, hopeless, and tired for
an unusually long time.With mania,
people feel extremely happy, confident,
and energetic. They are often too excited
People with a mental illness may not be
able to control their feelings.
In the
Middle Ages
(AD 500 to
1500) people
thought evil
spirits caused
mental illness.
