Chapter Nine: Memory

Chapter Nine: Memory
Overview of the Information Processing Model: Encoding
I. The information processing model views human (and computer) memory as a
system that encodes, stores, and retrieves bits of information. In humans,
information processing occurs in three systems: sensory memory, short-term
memory, memory.
II. Levels of processing
A. Shallow processing or maintenance rehearsal
1. Involves simple repetition of the presented material.
2. This is not an effective way to encode material.
3. Example:
Most people do not have accurate memories of the organization of numbers, letters,
and symbols on a push-button telephone, despite having seen and used them many,
many times.
B. Deep processing or elaborative rehearsal
1. Coding by forming associations between new information and information already
2. Makes information more meaningful.
3. Example:
If a student attempts to relate information presented in class to his or her own life, it
will be easier to remember in the future.
III. Subjective organization, or developing a personal way to categorize items, is
an effective way to improve encoding and thus recall.
IV. Mnemonic devices are memory devices for improving the encoding and
retrieval of information.
A. Single use mnemonics are designed to improve recall of a particular bit of
1. ROY G BIV represents the colors of the visible spectrum: red, orange, yellow,
green, blue, indigo, and violet.
2. "Spring forward, fall back" is a phrase to remind one which way to set a clock
when daylight savings time begins or ends.
B. The method of loci is a way to remember a list of objects with a numbered
sequence of images (e.g., one is a bun, two is a shoe, three is a target, etc.).
V. Activities
Lesson 2
Sensory Memory and Short-Term Memory
I. Sensory memory (also called sensory register)
A. A very brief memory for sensory information.
B. Allows us a very short period of time to review the overwhelming amount of
information. Most information is discarded, but some is selected for more extensive
C. Visual sensory register
1. Maintains an image of what we have seen for a few tenths of a second after the
stimulus has appeared. This kind of memory is called iconic.
2. Original research in this area involved the partial report technique developed
by George Sperling in the early 1960s to test subjects’ recall of letters presented in a
D. Auditory sensory register maintains the sounds we have heard for about 3 or 4
seconds after the stimulus; this kind of memory is called echoic.
II. Short-Term memory (also called working memory)
A. A limited, relatively brief storage system that holds items we are aware of and
working with at any given time.
B. Experiments indicate the duration of short-term memory is limited to about 18
seconds unless the subject rehearsed the information, in which case it is maintained
in short-term memory indefinitely.
C. Capacity of short-term memory
1. About seven items can be maintained in short-term memory if the information
was encoded acoustically.
2. The information held in short-term memory can be increased if it is organized into
chunks of meaningful or well-practiced information.
Lesson 3
Serial Position Effects and Long-Term Memory
I. Serial position effects. Our memory for a list of items tends to be better for
items at the beginning or the end of the list and worse for items in the middle of the
A. The primacy effect is the enhanced ability to recall items from the beginning of
the list.
B. The recency effect is the enhanced ability to recall items from the end of the list.
II. Long-Term Memory
A. Our most permanent memory store, with almost unlimited capacity and duration.
B. Types of long-term memories (Endel Tulvig)
1. Episodic memories are those for personally experienced events, such as what you
had for breakfast this morning.
2. Semantic memories are for general factual knowledge, such as the temperature
at which water boils.
3. Procedural memories are those that relate to skills or habits, such as your
memory of how to brush your teeth.
C. Explicit and implicit memories
1. Explicit (or declarative) memories are those of which one is consciously aware.
Example: I may have an explicit memory of playing a particular golf course.
2. Implicit (or non-declarative) memories are those of which one is not conscious.
Example: One may have implicit memories of how to tie one’s shoe but not be able
to describe to another how to do it.
Lesson 4
I. Reconstructive memory
A. The process of piecing together memories by fitting them to a meaningful plan or
B. Accounts for much of the inaccuracy of our recollections. We fill in gaps with
assumptions because we are uncomfortable with the gaps. Once we’ve done this,
distinguishing what actually happened from what we filled in is almost impossible.
II. Context
A. You recall more accurately in the same situation where the event originally took
B. Similar contexts may trigger feelings of deja vu.
III. State-dependent memory is the improved retrieval of material when one is in
the same mental, emotional, or drug-induced state that was present when the
material was originally learned.
IV. Eyewitness testimony
The work of Elizabeth Loftus and others has identified several aspects of eyewitness
A. The accuracy of eyewitness testimony can be influenced by the way questions are
B. Children are particularly susceptible to having false memories planted.
C. There is little correlation between witness certainty and witness accuracy. In other
words, witnesses who believe they are correct are no more likely to be correct than
witnesses who are not sure.
Lesson 5
Forgetting and the Biology of Memory
I. Forgetting
A. Decay theory
1. Argues that forgetting is caused by the passage of time.
2. No physiological mechanism to account for decay has been identified.
B. Interference theory
1. Argues that retrieval failure occurs when established associations conflict with
what we are trying to recall.
2. Types.
a. Proactive interference occurs when previous learning decreases your ability to
remember more recently learned material. For example, proactive interference
occurs if you can’t remember the name of the new assistant principal because all you
can think of is the name of the former assistant principal.
b. Retroactive interference occurs when recently learned material decreases your
ability to remember older material. For example, retroactive interference occurs if
you can’t remember the team that won last year’s World Series because all you can
think of is the team that won the Series this year.
C. Repression theory
1. Sigmund Freud argued that painful memories are self-censored and stored in the
unconscious mind.
2. The extent to which repression occurs is controversial.
II. Biology of memory
A. Cerebellum
1. Richard Thompson has found that a classically conditioned eye blink response in
rabbits stopped after a small area of the cerebellum was lesioned.
2. Evidence suggests that implicit memories are stored in the cerebellum.
B. The hippocampus seems to be where explicit memories are processed.