Download Human Memory II

Human Memory II
Acquisition and Retrieval
Presumably, we put information into LTM with the idea that we
might want to access it at a later time. If, however, we are unable
to retrieve it, having it in LTM would be of little value.
There are, of course, several ways of retrieving that information.
Most commonly by “recall” or “recognition.”
We might ask, then, how are acquisition and retrieval related?
Context-Dependent Learning
There is a great deal of evidence to support the notion that the
presence of connections formed during learning is important for
retrieval.
There are a variety of such “contextdependent” learning situations:
• Physical
• Emotional
• Mood congruence
• State-dependent
Context-Dependent Learning (con’t)
The conclusion is clear: recall is best when the external (or
internal) contexts of study and recall match.
You need not be physically in the same “place” when you are
learning and recalling. So long as the connections are
reinstated, successful retrieval is likely to occur.
Encoding Specificity
The to-be-remembered information is not the only thing that is
connected or “encoded” during learning. The specific thoughts
you have or perspective you take regarding the material during
learning are also encoded and, therefore, may serve as retrieval
paths.
However, the “extra” thoughts and perceptions can also alter the
meaning of what is remembered and, therefore, may affect
whether you can recall the information at a later time.
For example,
“The man lifted the piano” or “The man tuned the piano”
When a hint suggests a different context, recall suffers. This is
because we learn the word and context as a whole, not as
individual parts.
Different Forms of Memory Testing
We have just noted the importance of having study and
testing contexts match. Does our initial learning make a
difference if the retrieval is one of recall or recognition?
“Recall” refers to retrieving the material from memory by
searching until you’ve found what you’re looking for on your
own (e.g., Who wrote David Copperfield?).
“Recognition” refers to identifying “presented” material as
the material you are looking for. For example, _____ wrote
Little Women.
a) Laura Ingalls Wilder
b) Louisa May Alcott
c) Charlotte Brontë
d) Jane Austen
Memory Testing (con’t)
In both cases, we may be aware that we “know” the correct
response.
With “recognition,” however, we sometimes seem to get a
feeling that the material is “familiar,” but we don’t quite
know why (e.g., that person looks familiar, but I can’t put my
finger on where I know her).
That is, you lack source memory for the information.
Thus, our ability to recognize information sometimes occurs
because of “source memory” and sometimes because of
“familiarity.”
Implicit Memory
While we have conscious access to many of our memories,
there are those memories for which we do not, or only with
great difficulty (e.g., position of keys on typewriter, how to
shift gears in a car, how to tie a shoestring, etc.).
Explicit memories are those of which you are aware and can
recall or recognize.
Implicit memories are those of which you are unaware or
cannot recall, but can influence your behavior in some
manner (e.g., improved performance on a task) – what some
refer to as “memory without awareness.”
Implicit Memory (con’t)
There are a variety of ways we can demonstrate the existence
of implicit memories:
• Lexical-decision task
• Word-stem completion
• Savings
In these instances, subjects were influenced by previous
exposure to the material, yet were not able to directly recall
the material.
That phenomena is not limited to lists of words, but is easily
demonstrated in many real-world circumstances:
• False fame
• Illusion of Truth
Implicit Memory (con’t)
What is different in the False Fame and Illusion of Truth
examples is that subjects had a “feeling of familiarity” or
“that rings a bell” feeling and were required to interpret their
feelings.
In these instances, subjects were influenced by previous
exposure to the material, but in the absence of being able to
identify the “source” of the familiarity, their behavior was
determined by how they interpreted their feelings of
familiarity.
In real terms, seeing, hearing, or reading false information
provides familiarity and, at some later time, that familiarity
may be misinterpreted as “I’ve heard that before… I guess is
must be true.”
What Is Implicit Memory?
The idea that we can have “memory without awareness”
seems quite clear. It is important, then, to be able to explain
“implicit memory.”
Consider the following possibility: Implicit memory is the
manifestation of increased “processing fluency” resulting
from “practice” (i.e., previous exposure or mental effort)
Processing fluency may be thought of as an enhanced ability
to more quickly or efficiently process a stimulus.
What Is Implicit Memory? (con’t)
A few more (reasonable?) assumptions are needed to explain
other results (e.g., “familiarity”):
1. People are sensitive to degrees of processing fluency and easily
processed material results in a sense of “distinctiveness” or being
“special.”
2. An attribution process is triggered when material results in a sense of
distinctiveness and people are motivated to interpret the feeling as
familiarity and attribute it (correctly or incorrectly) to a source.
3. Decreases in processing fluency can result in material feeling
distinctive as well (e.g., when a friend shaves off their beard… you
know something is different, but can’t put your finger on it) which
will also trigger an attribution process.
Hippocampal Formation and Amnesia
The hippocampus is a structure embedded within the temporal
lobes and is considered critical for the formation of new
memories.
Damage (e.g., head injury, surgery, infection -- encephalitis,
Korsakoff’s syndrome resulting from chronic alcoholism) to the
hippocampus and surrounding structures can produce
retrograde (loss of memories before the damage) or
anterograde (inability to form new permanent memories)
amnesia.
As such, amnesia patients offer a unique opportunity for the
study of memory.
Amnesia (con’t)
“Working memory” seems to function normally, allowing for
interactions in the here-and-now.
In cases where the damage is not permanent (e.g., a blow to the
head) anterograde and retrograde amnesia show a “contracting”
pattern of recovery. Slowly, the patient shows the ability to learn
new things and recall of past events returns.
Older memories are usually preserved, but memories temporally
close to the injury are permanently lost.
Patients are able to remember things for short periods of time
(e.g., 10 seconds), but then forget them.
What Is The Problem?
Similar patterns of memory disruption are also seen in cases
where the damage is permanent.
It has longed be argued that anterograde amnesia was the result of
an inability for working memory to transfer information into
LTM.
However, there are many studies that question that argument:
• Acquisition of trivia
• Preference to previously heard songs
• Improvement in “mirror-drawing”
It seems that anterograde amnesic patients are able to acquire new
“implicit” memories but not new “explicit” memories, while other
cases show just the opposite. Such evidence supports the idea that
implicit and explicit memory are independent of each other.
Practical Advice For Optimal Learning
What practical lessons can we draw from all of this?
Since you will not always know under what conditions you
will be asked to recall or in what way you will be asked to
recall (i.e., recall or recognition), it is best to learn from as
many different perspectives as you can so you can establish
numerous connections between memories:
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Use elaborative rehearsal
Paraphrase the information
Develop multiple examples
Explain it to someone else
Get someone to quiz you
Etc.