Memory is the next part of our model of the user as an
information processing system. There are generally three types
of memory: sensory memory, short-term memory and long-term
The sensory memories act as buffers for stimuli received through
the senses. A sensory memory exists for each sensory channel:
iconic memory for visual stimuli, echoic memory for aural
stimuli and haptic memory for touch. Information is passed from
sensory memory into short-term memory by attention, thereby
filtering the stimuli to only those which are of interest at a
Short-term memory acts as a scratch-pad for temporary recall of
the information under process. For instance, in order to
understand this sentence you need to hold in your mind the
beginning of the sentence you read the rest. Short term memory
decays rapidly (200 ms.) and also has a limited capacity.
Chunking of information can lead to an increase in the short
term memory capacity. Thst is the reason why a hyphenated phone
number is easier to rememeber than a single long number. The
successful formation of a chunk is known as closure.
Interference often causes disturbance in short-term memory
retention. This accounts for the desire to complete the tasks
held in short term memory as soon as possible.
Long-term memory is intended for storage of information over a
long time. Information from the working memory is transferred to
it after a few seconds. Unlike in working memory, there is
What is a headache?
A Headache is defined as a pain in the head or upper neck. It is
one of the most common locations of pain in the body and has
How are headaches classified?
Headaches have numerous causes, and in 2007 the International
Headache Society agreed upon an updated classification system
for headache. Because so many people suffer from headaches and
because treatment sometimes is difficult, it is hoped that the
new classification system will allow health care practitioners
come to a specific diagnosis as to the type of headache and to
provide better and more effective treatment.
There are three major categories of headaches:
1. primary headaches,
2. secondary headaches, and
3. cranial neuralgias, facial pain, and other headaches
What are primary headaches?
Primary headaches include migraine, tension, and cluster
headaches, as well as a variety of other less common types of
Tension headaches are the most common type of primary headache.
Up to 90% of adults have had or will have tension headaches.
Tension headaches occur more commonly among women than men.
Migraine headaches are the second most common type of primary
headache. An estimated 28 million people in the United States
(about 12% of the population) will experience a migraine
headache. Migraine headaches affect children as well as adults.
Before puberty, boys and girls are affected equally by migraine
headaches, but after puberty, more women than men are affected.
It is estimated that 6% of men and up to 18% of women will
experience a migraine headache in their lifetime.