Memory
In Feb. 2002, prison warden James Smith lost
his set of master keys to the Westville
Correctional Facility. As a result, 2, 559
inmates were kept under partial lockdown
for eight days while the Indiana Department
of Correction spent $53,000 to change locks
in the effected area. It turned out that the
warden had put his keys in his pocket when
he went home, forgot he had done so, and
reported the keys “missing” when they were
not in there usual place in his office the next
day. What went wrong? There are several
possibilities.
Three Basic Processes
Encoding
• Encoding: as a visual or acoustic stimulus must be
transformed, so to must information be
transformed to a neural that memory can use.
• Listening to a lecture is acoustical encoding.
• Reading the power point slide of the same
material is visual encoding.
• If you remember the facts of a single slide, your
are using visual and/or acoustical encoding
encoding. If you remember there are other slides,
and you integrate the current slide with the other
slides, that is semantic encoding .
Storage Process
• Keeping information in memory over time,
some times over scores of years.
• Two basic mechanisms of storage, short-term
(18 seconds) and long-term, (a life time).
Long-term Memory
• Procedural (mainly motor learning).
• Autobiographical (episodic).
• Semantic: instances that happen during daily
life that were encoded into ones general
knowledge.
Retrieval Process
• Recall: brought from memory with out help of
context
• Recognition: aided by cues (context) using
possible alternative answers on a multiplechoice question to gain the correct answer.
Explicit and Implicit memory
• Explicit memory: When you intentionally try to
remember something and you are consciously aware
that you are doing so. Most of your formal college
education is a form of explicit memory
• Implicit: the unintentional recognition and influence of
prior experience. Reading the current slide a second
time, implicit memory of its content would help you to
read it more quickly, than you did the first time. This
occurs automatic without conscious effort. Episodic
semantic and procedural memories can be implicit or
explicit. But procedural usual operates implicitly.
Modes of memory
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Level of Processing model.
Transfer-Appropriate Processing model.
Parallel Distributive Processing (PDP) model.
Information Processing model
Levels of Processing model
• Suggests that the most important
determination of memory is how extensively
information is encoded or processed when it
is first received.
• Assume that one is trying to remember
something by rehearsing it. Maintenance
rehearsal vs Elaborative rehearsal.
•
Maintenance rehearsal
• The repeating over and over that which you
are trying to remember. Good for a very short
time. Example one looks up a telephone
number and wants to immediately dial that
number.
Elaborative rehearsal
• For long-term remembering it is better to
think how you can contextualize the new
material with other elements already stored in
memory. The richer the elaboration, the
deeper the information is stored in memory.
Transfer-Appropriate Processing model
• How well the process of retrieving information match the way
in which the information was first encoded.
• Consider the following: Half the students in this class were
told that an upcoming exam would be multiple-choice. The
remaining half were told the test would be and essay exam.
Only half of the students got the exam they were told they
would get. The remaining students got and unexpected exam.
Those students who got the expected exam did better than
those students who got an unexpected exam. The two groups
that studied for the expected exam encoded information
appropriate to the expected exam. Those who encoded for a
different exam than expected did poorer. Illustrates that the
match between encoding and retrieval processes can be as
depth of processing in memory
Parallel Distributed Processing (PDP)
• New experiences are integrated with existing
knowledge or memories, changing our overall
knowledge base and altering in a more
general way our understanding of the world
and how it operates. These theorist use
“neural networks” (the modern replacement
for artificial intelligence). Neural networks
allow all parts to be interconnected.
• When neural networks are applied to memory,
each unit of knowledge is seen as connected to
every other unit, and the connections between
units are seen as getting stronger and stronger
the more often the units are experienced
together (called, Hebb’s rules). From this
perspective the knowledge is distributed across
the dense network of associations. When the
network is activated, parallel processing begins.
That is, different portions of the network operate
simultaneously, allowing people to quickly draw
inferences and make generalizations.
Information Processing model (the
oldest of the modern memory models)
Sensory encoding
• Main function of sensory memory is to hold
the information in storage such that it can be
moved to short-term memory. Each sensory
modality has its own sensory storage capacity
with acoustic information being the fastest.
• These memories quickly fade if they are not
processed further. Highy adaptive.
Short-term memory
• The Magic Number Seven Plus or Minus Two
• Chunking: grouping information into useable
bites increases the ability to hold something
into short-term memory.
Working memory
• Working memory is the part of the memory
system that allows one to mentally work with,
or manipulate, the information being held in
short-term memory. So short-term memory is
a part of working memory. Together they
enable us to do many kinds of mental work.
An example of the two working together is
your purchasing of food and paying at the
counter.
Encoding in Short-term memory
• Acoustic codes: seen when make mistakes of
what they have heard. Mainly they involve
substitution of similar sounds. C for D, P, or T
• Visual codes: not as strong as acoustic codes
• Kinesthetic codes;
Duration of Short-term Memory
• Brown-Peterson study: What happens when
people are prevented from rehearsing.
• Subject is presented with a list of 3 letter
groups, GRB after viewing the letter, they are
asked to count backward by threes starting
with different numbers. At a signal the
subjects stop counting and try to recall the
letter groups.
Curve of forgetting using Brown-Peterson
procedure
Long-Term Memory
• Long –term memory can occur without
conscious processing, but in the main,
encoding in long-term memory is through
conscious semantic encoding.
• Sachs subjects to listen to tape recordings of
people speaking. She next shoed the subjects
sentences and asked them to say which
contained the exact wording heard on the tape.
The subjects did very well when they were tested
immediately (using working memory). After only
20 seconds, retrieving from long-term memory,
they could not determine which of two sentences
was correct is the two sentences expressed the
same meaning. The remembered the meaning of
what they heard but not the exact words.
• The errors occurred partly because people
encode into long-term memory not only the
general meaning of information but also what
the think and assume about that information.
• On the next slide there will appear some
words. Set up an alarm clock, watch or cell
phone to ring in 30 seconds. Study the words.
• When the clock alarm goes off. Look aside and
try and remember in any order the word list
you saw on the slide.
Which of the pictures below is that of a true
penny
• Counterfeiters on the fact that people encode
only the general meaning of visual, as well as,
auditory stimuli.
• In one study people viewed 2,500 pictures. It
took 16 hours to view all of the pictures. In a
later retrieval question the subject identified
90% of the pictures on which they were
tested.
• desk, chalk, pencil, chair, paperclip, book,
eraser, folder, briefcase, essays.
Serial position learning
• On average you learned the first word of the
list and the last word on the list better than
you learned the mid-word of the list. The first
word on the list in is the prime position, the
last word on the list is the last thing you were
likely to see (see the curve bellow).
Forgetting
We all forget
Ebbinghaus invented the nonsense syllable
• A meaningless se of two consonants and a
vowel, i.e. POF, XEM, QAL.
• He read list of nonsense syllables out lout at a
constant rate and then tried to remember
them.
• The method of savings = the number of trials
to learn the list – the number of trials to
relearn the list.
Ebbinghaus’s Curve of Forgetting
Ebbinghaus’s lasting discoveries
• The shape of the forgetting curve.
• Just how long-lasting savings in long-term
memory can be.
Process of Forgetting
• Decay: Over time the memory just diminishes
like a worn out machine.
• Interference: retrieval or storage is interfered
with new knowledge.
Type of Interference