Transcript Memory - Blinn College

Memory
Book author:
R.H. Ettinger
Chapter 7
This multimedia product and its contents are protected under copyright law.
The following are prohibited by law:
Slide authors:
Larry D. Thomas
Landon O. Thomas
•Any public performance or display, including transmission of any image over
a network;
•Preparation of any derivative work, including the extraction, in whole or in
part, of any images;
•Any rental, lease, or lending of the program
Copyright 2007 Horizon Textbook Publishing
Remembering
 Psychologists think of memory as involving
three processes
– Encoding
 Transforming information into a form that can be stored in
short-term or long-term memory
– Storage
 The act of maintaining information in memory
 Consolidation
– A physiological change in the brain that must take
place for encoded information to be stored in memory
– Retrieval
 The act of bringing to mind material that has been stored in
memory
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Atkinson-Shiffrin model
– Consists of three different, interacting memory
systems known as sensory, short-term, and longterm memory
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Sensory Memory
– The memory system that holds information coming
in through the senses for a period ranging from a
fraction of a second to several seconds
– Visual sensory memory lasts just long enough to
keep whatever you are viewing from disappearing
when you blink your eyes
– Auditory sensory memory lasts about 2 seconds,
and is experienced when the last few words
someone has spoken seem to echo briefly in your
head
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Sensory memory (continued)
– George Sperling
 Flashed 12 items of letters to participants
 Signaled the participants to report only the top, middle, or
bottom row of items by sounding a high, medium, or low
tone
 Found that participants could view the letters for 15/1000 to
½ second, they could report correctly all the items in any
row nearly 100% of the time
 But the items fade from sensory memory so quickly that
during the time it takes to report three or four of the items,
the other eight or nine have already disappeared
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Short-term memory
– The second stage of memory, which holds about
seven items for less than 30 seconds without
rehearsal
– Includes working memory; the mental workspace a
person uses to keep in mind tasks being though
about at any given moment
– Displacement
 The event that occurs when short-term memory is holding
its maximum and each new item entering short-term
memory pushes out an existing item
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 George A. Miller
– Capacity of short-term memory
 Miller’s “Magical Number”
 Capacity is limited to 7 +/- 2 items
– Duration of short-term memory
 items in short-term memory are lost in less than
30 seconds unless you repeat them over and
over to yourself
Developed the technique “chunking”
Grouping information to make it easier to
remember
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Rehearsal
– The act of purposely repeating information to
maintain it in short-term memory or to transfer it to
long-term memory
– Increasing the time in short-term memory makes it
more likely the information will be transferred to
long-term memory
– An interruption to rehearsal can cause information
to be lost in just a few seconds
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Short-term memory as working memory
– Allan Baddeley
 Suggested that “working memory” is a more fitting term
than short-term memory
– One of the most important working memory
processes is the application of memory strategies to
information
– Memory strategy involves manipulating information
in ways that make it easier to remember
 Elaborative rehearsal
– A technique used to encode information into long-term
memory by considering its meaning and associating it
with other information already stored in long-term
memory
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Read this list of words aloud at a rate of about one word
per second. Then click the mouse to have the words covered, and
write down all the words you can remember. Click the mouse
again when you are done writing down all the words you can
remember
bed
rest
awake
tired
dream
wake
snooze
doze
nap
yawn
snore
slumber
Now check your list. Did you “remember” the word sleep?
Many people do, even though it is not one of the words on the list
(Deese, 1959)
Copyright © 2004
2007 Allyn
Horizon
& Bacon
Textbook
All rights
Publishing
reserved
All rights reserved
Remembering
 Long-term memory
– The relatively permanent memory system with a
virtually unlimited capacity
– Some experts believe that there a two main
subsystems within long-term memory
 Declarative memory
 Nondeclarative memory
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Declarative memory
– also called explicit memory
– The subsystem within long-term memory that stores
facts, information, and personal life experiences
– Two types of declarative memory
 Episodic memory
– The subpart of declarative memory that contains
memories of personally experienced events
 Semantic memory
– The subpart of declarative memory that stores general
knowledge; a mental encyclopedia or dictionary
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Declarative memory (continued)
– Two types of declarative memory (continued)
 Semantic memory (continued)
– Brain-imaging studies show that the range of activity
for semantic memory is larger in the left than in the
right hemisphere
– Researchers have demonstrated that some people
who have suffered selective damage to their long-term
semantic memory can still learn and remember using
episodic memory
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Nondeclarative memory
– Also called implicit memory
– The subsystem within long-term memory that
consists of skills acquired through repetitive
practice, habits, and simple classically conditioned
responses
– Priming
 The phenomenon by which an earlier encounter with a
stimulus increases the speed or accuracy with which that
stimulus or a related stimulus can be named at a later time
 Can influence not only performance, but preferences and
behavior as well
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Levels-of-processing model
– A model of memory as a single system in which
retention depends on how deeply information is
processed
– Proposed by Craik and Lockhart
– With the shallowest levels of processing, a person is
merely aware of the incoming sensory information
– Deeper processing takes place only when the
person does something more with the information,
such as forming relationships, making associations,
attaching meaning to a sensory impression, or
engaging in active elaboration on new material
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Levels-of-processing model (continued)
– Craik and Tulving
 Tested the levels-of-processing model
 Had participants answer yes or no to questions asked
about words just before the words were flashed to them for
1/5 of a second
 Participants had to process the words visually, acoustically,
or semantically
 The test required shallow processing for the first question,
deeper processing for the second question, and still deeper
processing for the third question
 Later retention tests showed that the deeper the level of
processing, the higher the accuracy rate of memory
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Three kinds of memory tasks
– Recall
– Recognition
– Relearning
 Recall
– A measure of retention that requires a person to
remember material with few or no retrieval cues, as
in an essay test
– Trying to remember someone’s name, recalling
items on a shopping list, memorizing a speech or a
poem word for word, and remembering
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Which of the following test questions is more difficult?
1. What are the three basic memory processes?
2. Which of the following is NOT one of the three basic memory
processes?
A. encoding
B. retrieval
C. storage
D. relearning
 Most people think the second question is easier
because it requires only recognition memory
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Three kinds of memory tasks (continued)
– Recall (continued)
 May be made a little easier if cues are provided to jog
memory
 Sometimes serial recall is required; that is, information
must be recalled in a specific order
 In serial recall, each letter, word, or task may serve as a
cue for the one that follows
 Research suggests that, in free recall tasks, order
associations are more resistant to distractions than
meaningful associations
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Three kinds of memory tasks (continued)
– Recognition
 A measure of retention that requires a person to identify
material as familiar, or as having been encountered before
 Multiple-choice, matching, and true/false questions are
examples of recognition test items
 Main difference between recall and recognition is that a
recognition task does not require you to supply the
information but only to recognize it when you see it
 Recent brain-imaging studies have discovered that the
hippocampus plays an extensive role in memory tasks
involving recognition, and the degree of hippocampal
activity varies with the exact nature of the task
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Remembering
 Three kinds of memory tasks (continued)
– Relearning
 Measuring retention in terms of the percentage of time or
learning trials saved in relearning material compared with
the time required to learn it originally; also called the
savings method
 Savings score
– The percentage of time or learning trials saved in
relearning material over the amount of time or number
of learning trials required for the original learning
 College students demonstrate the relearning method each
semester when the study for comprehensive final exams
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Memory as a reconstruction
– Elizabeth Loftus
 Believes recal is not an exact replica of an event
 Rather a memory is a reconstruction
 Reconstruction
– A memory that is not an exact replica of an event but
has been pieced together from a few highlights, using
information that may or may not be accurate
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Sir Frederick Bartlett
– Studied memory using rich and meaningful material
learned and remembered under more lifelike
conditions
 Gave participants stories to read and drawings to study,
and at varying time intervals he had them reproduce the
original material
 Accurate reports were rare
 The participants seemed to reconstruct the material they
had learned, rather than actually remember it
 Errors in memory increased with elapse of time
 The parts his participants had created were often the very
parts that they most adamantly believed to have
remembered
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Sir Frederick Bartlett (continued)
– Concluded that people systematically distort the
facts and the circumstances of experiences
– Information already stored in long-term memory
exerts a strong influence on how people remember
new information and experiences
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Schemas and memory
– Schemas
 The integrated frameworks of knowledge and assumptions
a person has about people, objects, and events, which
affect how the person encodes and recalls information
 Schemas influence what people notice and how they
encode and recall information
 When we encounter new information or have a new
experience related to an existing schema, we try to make it
fit or be consistent with that schema
 To do this, we may have to distort some aspects of the
information and ignore or forget other aspects
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Distortion in memory
– Occurs when people alter the memory of an event
or an experience in order to fit their beliefs,
expectations, logic, or prejudices
– The tendency to distort makes the world more
understandable and enables people to organize
their experiences into their existing systems of
beliefs and expectations
– Bahrick and others
 Found that 89% of college students accurately remember
the A’s they earned in high school, but only 29% accurately
recalled the D’s
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Eyewitness testimony
– Studies on the accuracy of human memory suggest
that eyewitness testimony is highly subject to error
– Research suggests that it is better to have an
eyewitness first describe the perpetrator and then
search for photos matching that description than to
have the eyewitness start by looking through photos
and making judgments as to their similarity to the
perpetrator
– In lineups, subjects must resemble the suspect in
age, body build, and certainly in race
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Eyewitness testimony (continued)
– Some police officers and researchers prefer a “show
up”- presenting only one suspect and having the
witness indicate whether that person is the
perpetrator
– Eyewitnesses are more likely to identify the wrong
person if the person’s race is different from their
own
– Egeth
 Misidentifications are approximately 15% higher in crossrace than in same-race identifications
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Eyewitness testimony (continued)
– Questioning witnesses after a crime can influence
what they later remember
– Misinformation effect
 A phenomenon that happens when misleading information
is supplied after an event and causes erroneous
recollections of the actual event
– Eyewitnesses who perceive themselves to be more
objective have more confidence in their testimony,
regardless of its accuracy, and are more likely to
include incorrect information in their verbal
descriptions
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Recovering repressed memories
– Bass and Davis
 Not only sought to help survivors who remember having
suffered sexual abuse; they reached out as well to other
people who have no memory of any sexual abuse and tried
to help them determine whether they might have been
abused
 They suggested that “if you are unable to remember any
specific instances . . . but still have a feeling that something
abusive happened to you, it probably did”
– Many psychologists are skeptical, claiming that the
recovered memories are actually false memories
created by the suggestions of therapists
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Recovering repressed memories (continued)
– Loftus
 Believes that “the therapist convinces that patient with no
memories that abuse is likely, and the patient obligingly
uses reconstructive strategies to generate memories that
would support that conviction”
– Many research participants who are instructed to
imagine that a fictitious event happened do in fact
develop a false memory of the imagined event
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Recovering repressed memories (continued)
– Garry and Loftus
 Were able to implant a false memory of being lost in a
shopping mall at 5 years of age in 25% of participants aged
18 to 53, after verification of the fictitious experience by a
relative
– Infantile amnesia
 The relative inability of older children and adults to recall
event from the first few years of life
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Recovering repressed memories (continued)
– Widom and Morris
 Found that 64% of a group of women who had been
sexually abused as children reported no memory of the
abuse in a 2-hour interview 20 years later
– Williams
 Found that 38% of women who had documented histories
of sexual victimization did not report remember the sexual
abuse some 17 years later
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Recovering repressed memories (continued)
– The American Psychological Association, the
American Psychiatric Association, and the American
Medical Association hold the position that current
evidence supports the possibility that repressed
memories exist as well as that false memories can
be constructed in response to suggestion of abuse
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Flashbulb memories: extremely vivid memories
– Flashbulb memory
 An extremely vivid memory of the conditions surrounding
one’s first hearing the news of a surprising, shocking, or
highly emotional event
– Pillemer
 Argues that flashbulb memories do not constitute a
different type of memory altogether
 He suggests that all memories can vary on the dimensions
of emotion, consequentiality, and rehearsal
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Flashbulb memories: extremely vivid memories
(continued)
– Neiser and Harsch
 Questioned university freshmen about the Challenger
disaster the following morning
 When the same students were questioned again 3 years
later, one-third gave accounts that differed markedly from
those given initially, even though they were extremely
confident of their recollections
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Eidetic imagery
– The ability to retain the image of a visual stimulus
several minutes after it has been removed from view
– Some studies show that about 5% of children
apparently have something akin to photographic
memory
– Children with eidetic imagery generally have not
better long-term memory than others their age
– Virtually all children with eidetic imagery lose it
before adulthood
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Memory and culture
– Sir Frederick Bartlett
 Believed that some impressive memory abilities operate
within a social or cultural context and cannot be understood
as a pure process
 Described that amazing ability of the Swazi people of Africa
to remember the slight differences in individual
characteristics of their cows
 This is less surprising when you consider that the Swazi
people tend and depend on the cattle for their living
 He asked young Swazi men and young European men to
recall a message consisting of 25 words and neither group
had a better ability to recall
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Memory and culture (continued)
– Barbara Rogoff
 Maintains that such phenomenal, prodigious memory feats
are best explained and understood in their cultural context
– Some studies where conducted on a tribal group in
India, the Asur to test memory for location
 Researcher hypothesized that members of this group
would perform better on tests of memory for location than
on conventional tasks used by memory researchers
because, without artificial light, they have to remember
where things are in order to be able to move around in the
dark without bumping into things
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Nature of Remembering
 Memory and culture (continued)
– Cognitive psychologists have also found that we
more easily remember stories set in our own
cultures than those set in others
– In one study, researchers told women in the United
States and Aboriginal women in Australia a story
about a sick child
 Participants were randomly assigned to groups for whom
story outcomes were varied
 Aboriginal participants better recalled the story with the
native healer, while U.S. women were more accurate in
their recall of the story in which a physician treated the girl
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Factors Influencing Retrieval
 Serial position effect
– The tendency to remember the beginning and
ending items of a sequence or list better than the
middle items
– Primacy effect
 The tendency to recall the first items on a list more readily
than the middle items
– Recency effect
 The tendency to recall the last items on a list more readily
than those in the middle of the list
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Factors Influencing Retrieval
 Environmental context and memory
– Tulving and Thompson
 Suggest the elements of the physical setting in which a
person learns information are encoded along with the
information and become part of the memory trace
– Godden and Baddeley
 Conducted one of the early studies of context and memory
with members of a university diving club
 Participants memorized a list of words when they were
either 10 feet underwater or on land
 They were later tested for recall of the words in the same
or in a different environment
 Words were better recalled in the environment they were
learned
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Factors Influencing Retrieval
 Environmental context and memory
(continued)
– In a study, participants viewed videotapes and then
were tested on their memory of the videos in two
separate interviews conducted two days apart
– Half the participants were questioned by different
interviewers, whereas the other half were
questioned by the same interviewer in both sessions
– The participants who were questioned twice by the
same interviewer performed better than the other
participants on the memory task
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Factors Influencing Retrieval
 Environmental context and memory
(continued)
– Study by Morgan
 Participants were placed in isolated cubicles and exposed
to a list of 40 words
 They were instructed to perform a cognitive task using the
words but were not asked to remember them
 Experimental participants who experienced a pleasant odor
during learning and again when tested 5 days later had
significantly higher recall than control participants who did
not experience the odor during both learning and recall
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Factors Influencing Retrieval
 State-dependent effect
– The tendency to recall information better if one is in
the same pharmacological or psychological (mood)
state as when the information was encoded
– Participants learned (encoded) material while sober
or intoxicated, and later where tested in either the
sober or intoxicated state
– Recall was found to be best when the participants
were in the same state for both learning and testing
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Factors Influencing Retrieval
 State-dependent effect (continued)
– Evidence does suggest that anxiety and fear
influence memory
– Adults who are clinically depressed tend to recall
more negative life experiences and are likely to
recall their patents as unloving and rejecting
– A meta-analysis of 48 studies revealed a significant
relationship between depression and memory
impairment
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Biology and Memory
 Hippocampus and hippocampal region
– Hippocampal region
 A part of the limbic system, which includes the
hippocampus itself and its underlying cortical areas
– Case of H. M.
 A man who suffered from severe epilepsy agreed to a
surgical procedure
 The surgeon removed the part of the brain believed to be
causing H. M.’s seizures, the medial portions of both
temporal lobes-the amygdala and the hippocampal region
 After his surgery, H. M. remained intelligent and
psychologically stable, and his seizures were drastically
reduced
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Biology and Memory
 Hippocampus and hippocampal region
(continued)
– Case of H. M. (continued)
 But the tissue cut from H. M.’s brain also contained his
ability to use working memory to store new information in
long-term memory
 H. M. suffers from anterograde amnesia
– The inability to form long-term memories of events
occurring after a brain injury or brain surgery, although
memories formed before the trauma are usually intact
 Though H. M. could still form nondeclarative memories;
that is, he could still acquire skills through repetitive
practice although he could not remember having done so
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Biology and Memory
 Hippocampus and hippocampal region
(continued)
– Research has established that the hippocampus is
critically important for storing and using mental
maps to navigate in the environment
– The observed reorganization of neural circuits in the
hippocampus of the London taxi drivers confirms
that brain plasticity in response to environmental
demands can continue into adulthood
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Biology and Memory
 Neuronal changes in memory
– Eric Kandel and his colleagues
 Provided the first close look at the nature of memory in
single neurons
 Traced the effects of learning and memory in sea snail
 Using tiny electrodes implanted in several single neurons
in the sea snail, the researchers mapped the neural circuits
that are formed and maintained as the animal learns and
remembers
 Also discovered the different types of protein synthesis that
facilitate short-term and long-term memory
 Kandel won a Nobel Prize in 2000 for his work
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Biology and Memory
 Neuronal changes in memory (continued)
– Donald O. Hebb
 Argued that the necessary neural ingredients for learning
and memory must involve the enhancement of
transmission at the synapses
– Long-term potentiation (LTP)
 A long-lasting increase in the efficiency of neural
transmission at the synapses
 LTP is important because it appears to be the basis for
learning and memory at the level of the neurons
 Does not take place unless both the sending and receiving
neurons are activated at the same time by intense highfrequency stimulation; the receiving neuron must also be
depolarized when the stimulation arrives
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Biology and Memory
 Neuronal changes in memory (continued)
– Davis and others
 Gave rats a drug that blocks certain receptors in sufficient
doses to interfere with a maze-running task
 Discovered that LTP in the hippocampus was also
disrupted
– Riedel
 Found that LTP is enhanced and memory is improved
when a drug that excites those same receptors is
administered shortly after maze training
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Biology and Memory
 Hormones and memory
– McGaugh and Cahill
 Suggests that there may be two pathways for forming
memories-one for ordinary information and another for
memories that are fired by emotion
 When a person is emotionally aroused, the adrenal glands
release the hormones adrenalin and noradrenaline into the
bloodstream
– Excessive levels of stress hormone cortisol, has
been shown to interfere with memory in patients
who suffer from diseases of the adrenal glands
– Estrogen, the female sex hormone, appears to
improve working memory efficiency
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Forgetting
 Ebbinghaus and the first experimental studies
on forgetting
– Hermann Ebbinghaus
 Conducted the first experimental studies on learning and
memory
 Invented the nonsense syllable
– A consonant-vowel-consonant combination that does
not spell a word
 Conducted his studies on memory using 2,300 nonsense
syllables as his material and himself as the only participant
 Carried out all his experiments at about the same time of
day in the same surroundings
 Memorized lists of nonsense syllables by repeating them
over and over at a constant rate of 2.5 syllables per second
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Forgetting
 Ebbinghaus and the first experimental studies
on forgetting (continued)
– Hermann Ebbinghaus (continued)
 He repeated a list until he could recall it twice without error,
a point he called “mastery”
 He recorded the amount of time or the number of trials it
took to memorize his lists to mastery
 After different periods of time had passed and forgetting
had occurred, he recorded the amount of time or number of
trials needed to relearn the same list to mastery
 The percentage of savings represented the percentage of
the original learning that remained in memory
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Forgetting
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Forgetting
 Causes of forgetting
– Encoding failure
 A cause of forgetting resulting from material never having
been put into long-term memory
– Decay theory
 A theory of forgetting that holds that the memory trace, if
not used, disappears with the passage of time
 Harry Bahrick and others
– Found that after 35 years, participants could recognize
90% of their high school classmates’ names and
photographs-the same percentage as for recent
graduates
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Forgetting
 Causes of forgetting (continued)
– Interference
 Memory loss that occurs because information or
associations stored either before or after a given memory
hinder the ability to remember it
 Proactive interference
– Occurs when information or experiences already
stored in long-term memory hinder the ability to
remember newer information
 Retroactive interference
– Happens when new learning interferes with the ability
to remember previously learned information
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Forgetting
 Causes of forgetting (continued)
– Consolidation failure
 Any disruption in the consolidation process that prevents a
permanent memory from forming
 Retrograde amnesia
– A loss of memory affecting experiences that occurred
shortly before a loss of consciousness
 Nader and others
– Demonstrated that conditioned fears in rats can be
erased by infusing into the rats’ brains a drug that
prevents protein synthesis
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Forgetting
 Causes of forgetting (continued)
– Sigmund Freud
 Motivated forgetting
– Forgetting through suppression or repression in order
to protect oneself from material that is too painful,
anxiety- or guilt-producing, or otherwise unpleasant
 Repression
– Removing from one’s consciousness disturbing, guiltprovoking, or otherwise unpleasant memories so that
one is no longer aware that a painful event occurred
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Forgetting
 Causes of forgetting (continued)
– Amnesia
 A partial or complete loss of memory resulting form brain
trauma or psychological trauma
– Prospective forgetting
 Forgetting to carry out some action, such as mailing a letter
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Forgetting
 Causes of forgetting (continued)
– Retrieval failure
 When someone is certain that they know something, but
they are not able to retrieve the information when they
need it
 Endel Tulving
– Claims that much of what people call forgetting is really
an inability to locate the needed information
– Found that participants could recall a large number of
items they seemed to have forgotten if he provided
retrieval cues to jog their memory
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Improving Memory
 How information is organized strongly
influences your ability to remember it
 Overlearning
– Practicing or studying material beyond the point
where it can be repeated once without error
– Research suggests that people remember material
better and longer if they overlearn it
– Krueger
 Showed very substantial long-term gains for participants
who engaged in 50% and 100% overlearning
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Improving Memory
 Spacing study over several different sessions
generally is more effective than massed
practice
– Massed practice
 Learning in one long practice session as opposed to
spacing the learning in shorter practice sessions over an
extended period
 Long periods of memorizing make material
particularly subject to interference and often
result in fatigue and lowered concentration
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Improving Memory
 Recent research suggests that significant
improvement in learning results when spaced
study sessions are accompanied by short,
frequent tests of the material being studied
 The spacing effect applies to learning motor
skills as well as to learning facts and
information
Copyright © 2007 Horizon Textbook Publishing All rights reserved
Improving Memory
 A. I. Gates
– Tested groups of students who spent the same
amount of time in study, but who spent different
percentages of that time in recitation and rereading
– Participants recalled two to three times more if they
increased their recitation time up to 80% and spent
only 20% of their study time rereading
Copyright © 2007 Horizon Textbook Publishing All rights reserved