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UNIT 3
Regulation and Integration of the Body
12
Memory
is the storage and retrieval of information. Memories
are essential for learning and incorporating our experiences into
behavior and are part and parcel of our consciousness. Stored
somewhere in your 3 pounds of wrinkled brain are zip codes,
the face of your grandfather, and the taste of yesterday’s pizza.
Your memories reflect your lifetime.
Stages of Memory
Memory storage involves two distinct stages: short-term mem-
ory and long-term memory
(Figure 12.20)
.
Short-term memory (STM)
, also called
working memory
,
is the preliminary step, as well as the power that lets you look
up a telephone number, dial it, and then never think of it again.
STM is limited to seven or eight chunks of information, such as
the digits of a telephone number or the sequence of words in an
elaborate sentence.
In contrast,
long-term memory (LTM)
seems to have a lim-
itless capacity. Although our STM cannot recall numbers much
longer than a telephone number, we can remember scores of
telephone numbers by committing them to LTM. However,
long-term memories can be forgotten, and so our memory bank
continually changes with time. Furthermore, our ability to store
and retrieve information declines with aging.
We do not remember or even consciously notice much of
what is going on around us. As sensory inputs flood into our
cerebral cortex, they are processed (yellow box in Figure 12.20).
Some 5% of this information is selected for transfer to STM
(light green box in Figure 12.20). STM serves as a temporary
holding bin for data that we may or may not want to retain.
Information is then transferred from STM to LTM (dark
green box in Figure 12.20). Many factors can influence this
transfer, including:
Emotional state.
We learn best when we are alert, motivated,
surprised, and aroused. For example, when we witness shock-
ing events, transferral is almost immediate. Norepinephrine,
a neurotransmitter involved in memory processing of emo-
tionally charged events, is released when we are excited or
“stressed out,” which helps to explain this phenomenon.
Rehearsal.
Rehearsing or repeating the material enhances
memory.
Association.
Tying “new” information to “old” information
already stored in LTM appears to be important in remem-
bering facts.
Automatic memory.
Not all impressions that become part
of LTM are consciously formed. A student concentrating on
a lecturer’s speech may record an automatic memory of the
pattern of the lecturer’s tie.
Memories transferred to LTM take time to become perma-
nent. ±e process of
memory consolidation
apparently in-
volves fitting new facts into the categories of knowledge already
stored in the cerebral cortex.
Categories of Memory
±e brain distinguishes between factual knowledge and skills,
and we process and store these two kinds of information in dif-
ferent ways.
produce a type of nonsense o²en referred to as “word salad.”
±ey also have great difficulty understanding language.
Recent imaging studies of the brain indicate that this picture
is clinically useful, but oversimplified. In fact, Broca’s and Wer-
nicke’s areas together with the basal nuclei form a single language
implementation system that analyzes incoming and produces
outgoing word sounds and grammatical structures. A surround-
ing set of cortical areas forms a bridge between this system and
the regions of cortex that hold concepts and ideas, which are dis-
tributed throughout the remainder of the association cortices.
±e corresponding areas in the right or non-language-dominant
hemisphere are involved in “body language”—the nonverbal emo-
tional (affective) components of language. ±ese areas allow the
lilt or tone of our voice and our gestures to express our emotions
when we speak, and permit us to comprehend the emotional con-
tent of what we hear. For example, a so², melodious response to
your question conveys quite a different meaning than a sharp reply.
Memory
Compare and contrast the stages and categories of
memory.
Describe the roles of the major brain structures believed to
be involved in declarative and procedural memories.
Outside stimuli
General and special sensory receptors
Short-term
memory (STM)
Data transfer
influenced by:
Excitement
Rehearsal
Associating new data
with stored data
Long-term
memory
(LTM)
Data permanently lost
Afferent inputs
Retrieval
Forget
Forget
Data selected
for transfer
Automatic
memory
Data unretrievable
Temporary storage
(buffer) in cerebral cortex
Figure 12.20
Memory processing.
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