Chapter 7 Memory - PowerPoint PPT Presentation

1 / 117
About This Presentation
Title:

Chapter 7 Memory

Description:

... interference, but it generally does not decay due to the effects of time alone. ... something for the long-term, study and review it under varying conditions with ... – PowerPoint PPT presentation

Number of Views:113
Avg rating:3.0/5.0
Slides: 118
Provided by: Jos562
Category:

less

Transcript and Presenter's Notes

Title: Chapter 7 Memory


1
Chapter 7Memory
2
Memory
  • Memory is a general term for the storage,
    retention and recall of events, information and
    procedures.
  • The quality of an individuals memory may vary
    based upon the nature of the information being
    retained and recalled, the level of interest in
    it, and its significance to that individual.

3
Module 7.1
  • Varieties of Memory

4
Ebbinghauss Pioneering Studies of Memory
  • Hermann Ebbinghaus studied his own ability to
    memorize new material
  • He invented over 2300 nonsense syllables and put
    them into random lists.
  • Over 6 years he memorized thousands of lists of
    nonsense syllables.
  • Generally he found that delay between
    memorization and recall resulted in the
    forgetting of a large portion of the material.

5
  • Figure 7.1 Hermann Ebbinghaus pioneered the
    scientific study of memory by observing his own
    capacity for memorizing lists of nonsense
    syllables.

6
Ebbinghauss Pioneering Studies of Memory
  • Role of interference
  • Part of the difficulty for Ebbinghaus may have
    been the fact that he memorized so many lists of
    nonsense syllables.
  • If an individual learns several sets of related
    materials, the retention of the old material
    makes it harder to retain new material, and the
    learning of the new materials makes it harder to
    retain the old.
  • This phenomenon is known as interference.

7
Ebbinghauss Pioneering Studies of Memory
  • Role of interference
  • When retaining old material makes it hard to
    retain new material, this is called proactive
    interference.
  • When learning new material makes it hard to
    retain old material, this is called retroactive
    interference.
  • The problem for Ebbinghaus was that he had
    memorized so many lists of nonsense syllabus that
    he experienced a strong effect from proactive
    interference.

8
Concept Check
  • You answer the telephone at your new receptionist
    job with the name of the your former employers
    firm. What kind of interference caused this
    embarrassing slip-up?

Proactive interference
9
Ebbinghauss Pioneering Studies of Memory
  • Meaningfulness
  • Another feature of the pioneering work of
    Ebbinghaus is that he memorized nonsense
    syllables.
  • It is clear from studies of memory that
    meaningful materials are easier to remember.
  • It is also true that distinctive or unusual
    information is easier to retain.
  • The tendency of people to remember unusual items
    better than more common items is called the von
    Restorff effect.

10
Ebbinghauss Pioneering Studies of Memory
  • Dependence of memory on the method of testing
  • It is possible that since Ebbinghaus required
    himself to repeat the syllables in correct order
    after memorizing them, he underestimated his
    actual retention of the information.
  • How well one appears to remember something
    depends in part on how one is tested after
    learning.

11
Ebbinghauss Pioneering Studies of Memory
  • Dependence of memory on the method of testing
  • Recall (or free recall) is the simplest method
    for the tester but the most difficult for the
    person being tested. To recall something is to
    produce it, as is done on essay and short-answer
    tests.
  • Cued recall gives the person being tested
    significant hints about the correct answer. A
    fill-in-the-blank test uses this method.

12
  • Table 7.1 The difference between recall and cued
    recall

13
Ebbinghauss Pioneering Studies of Memory
  • Dependence of memory on the method of testing
  • Recognition is the method that requires the
    person being tested to identify the correct item
    from a list of several choices. Multiple-choice
    tests use the recognition method.
  • The savings, or relearning method compares the
    rate at which someone relearns material as
    opposed to learning something new. The amount of
    time saved between the original learning and the
    relearning is a measure of memory.

14
Ebbinghauss Pioneering Studies of Memory
  • We are indebted to Ebbinghaus for initiating the
    scientific study of memory.
  • We have also learned important facts about the
    nature of memory from his difficulties with
    interference.

15
Concept Check
  • The bonus question on your Introductory
    Psychology test asks you to name the stages of
    the human sleep cycle.

Recall
16
Concept Check
  • You are on a game show and the question that you
    must answer is _________ is the city that is
    home to the Eiffel Tower, the Louvre, and the
    Cathedral of Notre Dame.

Cued recall
17
Concept Check
  • You answer more questions on the subject of
    molecular biology correctly on the comprehensive
    semester final than you did on the chapter test
    two months earlier.

Relearning or Savings
18
Concept Check
  • While at a hardware store, you are looking at
    several shades of light green paint in hopes of
    repainting the walls of your home in that exact
    shade.

Recognition memory
19
The Information-Processing View of Memory
  • The information-processing model of memory draws
    an analogy between a computer and the workings of
    memory in the human brain.
  • According to this view, information enters the
    system, is processed and coded in various ways,
    and is then stored.

20
  • Figure 7.4 The information-processing model of
    memory resembles a computers memory system,
    including temporary and permanent memory.

21
The Information-Processing View of Memory
  • The computer has a buffer a temporary storage
    place for letters that you type faster than it
    can display them.
  • This is akin to our sensory memory store

22
The Information-Processing View of Memory
  • The computer has RAM, or random-access memory,
    for temporary storage of information that has not
    yet been written to the hard drive. This
    information is still vulnerable to damage or
    loss.
  • This is analogous to our short-term, or working
    memory.

23
The Information-Processing View of Memory
  • The computer has a hard drive, in which
    information that you are writing or entering can
    be permanently stored.
  • This is like our long-term memory.

24
The Information-Processing View of Memory
  • The sensory store
  • Although it is probably more accurately described
    as a combination of memory and perception, the
    sensory store is considered to be the first stage
    of memory processing.
  • It is a very brief (less than a second) stage
    that registers everything that is perceived in
    the moment that we call now.

25
  • Figure 7.5 George Sperling (1960) flashed arrays
    like this on a screen for 50 milliseconds. After
    the display went off, a signal told the viewer
    which row to recite.

26
The Information-Processing View of Memory
  • Short-term and long-term memory
  • Temporary storage of information that someone has
    just encountered is short-term memory.
  • Long-term memory is a relatively permanent
    storage of mostly meaningful information.
  • Reminders or hints that help us to retrieve
    information from long-term memory are referred to
    as retrieval cues.

27
The Information-Processing View of Memory
  • Short-term memory
  • If a friend asks you what he or she just said,
    and you were paying attention, you could probably
    repeat their words or something close to them.
  • This is because you are being asked to recall
    something from short-term memory.
  • If you were not paying attention, you would not
    recall it at all. Attention is the process that
    moves information from the sensory store to
    short-term memory.

28
  • Table 7.3 After about 1 second, you can no longer
    recall information from the sensory store.
    Short-term memories can be recalled up to about
    20 seconds without rehearsalmuch longer if you
    continually rehearse them. Long-term memories
    decline somewhat, especially at first, but you
    may be able to retrieve
  • them for a lifetime. Your address from years ago
    is probably in your long-term memory and will
    continue to be for the rest of your life.

29
The Information-Processing View of Memory
  • Long-term memory
  • If your psychology instructor asks you to name
    the function of the thalamus, your first reaction
    might be to panic because you have no idea.
  • The instructor says, It has something to do with
    sensory information, right?

30
The Information-Processing View of Memory
  • Long-term memory
  • Then it begins to come back to you the thalamus
    is a relay and integration station for sensory
    information on its way to the cerebral cortex.
  • The instructor gave you a hint that functioned as
    an effective retrieval cue. These cues can be
    generated internally or be suggested by others.

31
The Information-Processing View of Memory
  • Capacities of short and long-term memory
  • Most normal adults can immediately repeat a list
    of about seven bits or pieces of information,
    with expected variations in range from five to
    nine items.
  • This magic range of 7 /- 2 bits is a
    well-replicated finding regarding the capacity of
    short-term memory.
  • It can be expanded through techniques such as
    chunking into larger, meaningful units.

32
  • Figure 7.6 We overcome the limits of short-term
    memory through chunking. You probably could not
    remember the 26-digit number in (a), but by
    breaking it up into a series of chunks, you can
    remember it and dial the number correctly.

33
The Information-Processing View of Memory
  • Capacities of short and long-term memory
  • The capacity of long-term memory cannot easily be
    measured.
  • Unlike a computer, we are not dealing with a
    physical limit of size.
  • Humans are constantly dumping or removing some of
    their stored information through disuse.

34
The Information-Processing View of Memory
  • Decay of short and long-term memory
  • Information that has been stored in long-term
    memory may be vulnerable to the aforementioned
    effects of interference, but it generally does
    not decay due to the effects of time alone.
  • Information being held in short-term memory is
    vulnerable immediately to the effects of the
    passage of time.
  • Forgetting tends to begin in seconds unless
    rehearsal is permitted.

35
  • Figure 7.9 In a study by Peterson and Peterson
    (1959), people remembered a set of letters well
    after a short delay, but their memory faded
    greatly over 20 seconds if they were prevented
    from rehearsing during that time.

36
The Information-Processing View of Memory
  • Capacities of short and long-term memory
  • How long one is able to hold information in
    short-term memory has little relationship to how
    well it will be stored in long-term memory.
  • If the information being held in short-term
    memory is meaningful, it will be transferred
    easily to long-term memory and be less subject to
    decay.
  • Up until recently, cognitive psychologists
    referred to this transfer process as
    consolidation, the formation of a long-term
    memory.

37
The Information-Processing View of Memory
  • Capacities of short and long-term memory
  • It is now thought that how easily information is
    consolidated depends on its meaningfulness to the
    individual. This idea implies that perhaps the
    division between the short and long-term memory
    stages is at least in part an artificial one.
  • If the information is meaningful, the groundwork
    for storing that information has already been
    done.

38
The Information-Processing View of Memory
  • Working memory
  • Working memory is a revised concept of the
    intermediate stage between our first encounter
    with new information and its eventual storage.
  • Working memory is a system for processing or
    working with current information.
  • Working memory is conceptualized as having three
    major components.

39
The Information-Processing View of Memory
  • Working memorys 3 components
  • A phonological loop that stores and rehearses
    information, similar to the 7 /- 2 idea from the
    traditional concept of short-term memory.
  • A visuospatial sketchpad that stores and
    manipulates visual and spatial information.
  • A central executive that governs shifts of
    attention. Good working memory is able to handle
    shifts between two or more tasks or multiple
    aspects of complex tasks.

40
The Information-Processing View of Memory
  • Other memory distinctions
  • Declarative memory is the ability to state a
    fact.
  • Procedural memory is the memory of how to do
    something.
  • Long-term declarative memory is classified as
    either semantic (dealing with principles of
    knowledge) or episodic (containing events and
    details of life history.)
  • Your memory of a recent piano lesson is
    declarative and episodic your memory of how to
    read music is semantic your memory of how to
    play the piano is procedural.

41
The Information-Processing View of Memory
  • Other memory distinctions
  • A normal type of forgetting is source amnesia.
  • This involves a combination of episodic and
    semantic memory. We remember a statement or
    knowledge related (semantic) fact but we forget
    the context in which we learned it.

42
The Information-Processing View of Memory
  • Other memory distinctions
  • The context in which one learns information is
    episodic.
  • It can be inferred from the occurrence of this
    phenomenon that episodic memory is more fragile
    than semantic knowledge.

43
Varieties of Memory
  • Although there is still much disagreement about
    the nature of memory, there is general agreement
    that memory is not a single store into which we
    dump the sum of our knowledge and experiences.

44
Varieties of Memory
  • Memory is a complex combination of many
    processes, and its properties depend on a number
    of factors
  • The type of material memorized
  • The individuals experience with similar
    materials
  • The method of testing
  • The length of time since the material was
    encountered

45
Module 7.2
  • Long Term Memory Storage

46
Memory Improvement
  • To improve memory, one must improve the
    strategies used to originally store the material.

47
The Influence of Emotional Arousal
  • It is well understood that the greater the
    emotional arousal associated with an event, the
    greater the likelihood that the event will be
    remembered.
  • Although the event itself may be remembered, the
    emotion associated with the event does not
    guarantee the formation of an accurate memory for
    the details of the event.

48
The Influence of Emotional Arousal
  • During stressful or emotional events, the
    sympathetic nervous system works to boost
    production of the hormones cortisol and
    adrenaline.
  • This is usually accompanied by increased
    stimulation of the amygdala.
  • The net effect of these processes is to enhance
    memory storage of information associated with
    emotional or stressful events.

49
Concept Check
  • A Vietnam War Veteran who was involved in several
    very intense and violent campaigns has been
    medically monitored for years. He has lower than
    normal levels of cortisol. How would this affect
    his memory?

He should report frequent memory lapses.
50
Meaningful Storage and Levels of Processing
  • The levels-of-processing principle
  • The levels-of-processing principle states that
    the ease with which we can retrieve a memory
    depends on the number and types of associations
    that we form with that memory
  • The more ways in which you think about the
    material, the deeper your processing will be and
    the more easily you will remember the material
    later.

51
Meaningful Storage and Levels of Processing
  • The levels-of-processing principle
  • Ways to think about the material would include
    asking questions such as
  • Can I think of similar concepts in another
    subject area?
  • How do these apply to me?
  • What experiences do I have that are related to
    this information?

52
Meaningful Storage and Levels of Processing
  • The levels-of-processing principle
  • To improve your level-of-processing
  • Think about each individual item in a set that
    you are trying to learn.
  • See if you can determine whether or not
    relationships exist among the items.

53
Meaningful Storage and Levels of Processing
  • The levels-of-processing principle
  • The levels of processing are
  • Superficial processing simply repeating the
    material that you are trying to memorize.
  • Deeper processing think about each item or
    parts of the material individually.
  • Still deeper processing note the associations
    between the items or parts of the material.

54
Concept Check
  • Who do you think tends to get better grades in a
    course, students who read the book quickly or
    those who read the book slowly?

The slow pokes
55
Concept Check
  • How would level-of-processing be useful to
    aspiring actors?

It would help them memorize their lines more
effectively.
56
Timing of Study Sessions
  • The serial-order effect
  • The serial-order effect states that we tend to
    remember the beginning and end of a list better
    than the middle.
  • The primacy effect is the tendency to remember
    the beginning.
  • It is partly due to the lack of proactive
    interference while you rehearse the first few
    items.
  • The recency effect is the tendency to remember
    the end.
  • The last few items are not subject to as much
    retroactive interference.

57
Timing of Study Sessions
  • Because of these effects, the best strategy for
    anyone who needs to learn a lot of material is to
    space out the study sessions
  • Study the material
  • Wait for awhile
  • Return to the material and test yourself on it

58
Timing of Study Sessions
  • The SPAR method
  • If you want to remember something for the
    long-term, study and review it under varying
    conditions with substantial intervals between
    sessions
  • One systematic way to accomplish this is to use
    the SPAR method.

59
Timing of Study Sessions
  • The SPAR method
  • Survey get an overview of the material.
  • Process meaningfully read the material
    carefully and think about how it relates to your
    other knowledge and experiences.
  • Ask questions use the review questions included
    with the material, or create your own and answer
    them.
  • Review wait a day or so, and retest yourself.

60
Concept Check
  • In order to ace your comprehensive Introductory
    Psychology final exam, should you immediately
    review this chapter, or should you schedule some
    review of the first two or three chapters?

Start reviewing the earlier material
61
Use of Special Coding Strategies
  • Retrieval Cues
  • Retrieval cues are bits of associated information
    that help you to regain complex memories for
    later use. Many factors associated with learning
    can act as retrieval cues.
  • The encoding specificity principle states that
    the associations formed at the time of learning
    are typically the most effective retrieval cues.
  • State-dependent memory is our tendency to
    remember something better if your physical
    condition is the same at the time of recall as it
    was at the time of learning.

62
  • Figure 7.11 According to the principle of
    encoding specificity, the way we code a word
    during original learning determines which cues
    will remind us of that word later. For example,
    when you hear the word queen, you may think of
    that word in any of several ways. If you think of
    queen bee, then the cue playing card will not
    remind you of it later. If you think of the queen
    of England, then chess piece will not be a good
    reminder.

63
  • Table 7.5a

64
  • Table 7.5b

65
Use of Special Coding Strategies
  • Mnemonic devices
  • A mnemonic device is any memory aid that is based
    on encoding each item in a special way. There are
    many types of mnemonic devices.
  • The method of loci involves memorizing a series
    of places. Using a vivid image, you associate
    each of these locations with something you want
    to remember.
  • The peg method involves memorizing a list of
    objects (pegs) and forming mental images to
    link the information that you wish to memorize
    using these pegs.

66
  • Figure 7.12 A simple mnemonic device is to think
    of a short story or image that will remind you of
    what you need to remember. Here you might think
    of images to help remember functions of different
    brain areas.

67
  • Figure 7.14 The method of loci is one of the
    oldest mnemonic devices. First, learn a list of
    places, such as my desk, the door of my room,
    the corridor, . . . Then link each of these
    places to the items on a list of words or names,
    such as a list of the names of Nobel Peace Prize
    winners.

68
Improving Our Memory
  • We refer to our memories as stored and
    retrieved as if they were items on a shelf in a
    warehouse. But this analogy is only partially
    useful.
  • The more you know about a topic, the more
    interested you are in it, the easier it is to
    establish and retain new information related to
    the topic.

69
Normal Forgetting
  • There are many plausible reasons to account for
    the forgetting of information
  • Interference
  • Decay the memory is subject to the combined
    effects of time and interference
  • Loss of retrieval cues
  • Source amnesia

70
Module 7.3
  • Retrieval of Memories

71
Reconstructing Past Events
  • When you try to remember an event, you usually
    start with details you remember clearly, and fill
    in the gaps.
  • This is the process of reconstruction. During an
    event, we construct a memory. When we try to
    retrieve the memory, we reconstruct an account
    based partly on surviving memories and partly on
    expectations of what must have happened.

72
Reconstructing Past Events
  • Your memory for activities that are routine
    your breakfast, lunch or dinner for example
    from the past week can be reconstructed with
    little effort. But these will fade rapidly
    unless something unusual happened.

73
Reconstructing Past Events
  • If your family all got sick after one meal, you
    will probably remember that meal in better detail
    for much longer than is usual.
  • If you met a new love interest when you were out
    to dinner with friends, this event will also be
    more memorable and easily reconstructed.
  • However, you may fill in missing details with
    typical activities associated in your memory with
    routine meals at home or dining out.

74
Reconstructing Past Events
  • We will add words to lists that weve heard or
    read depending on what content we believe would
    have been on the list, based on its apparent
    theme.
  • The less certain of our memories that we are, the
    more we will rely on our expectations.

75
Reconstructing Past Events
  • Hindsight bias
  • Hindsight bias is the tendency to mold our
    recollection of the past to how events later
    turned out.
  • We say I knew that was going to happen! after
    the event has occurred.
  • Our memories are tailored as we reconstruct the
    event to fit that outcome.

76
  • Figure 7.17a Mean estimates of the likelihood of
    four outcomes varied depending on what each group
    was told about the actual outcome. Those who
    thought the British had won said that under the
    circumstances the British had a very high
    probability of victory. Those who thought the
    Gurkas had won said that was the most likely
    outcome under the circumstances, and so forth.
    (Based on data of Fischhoff, 1975)

77
  • Figure 7.17b Mean estimates of the likelihood of
    four outcomes varied depending on what each group
    was told about the actual outcome. Those who
    thought the British had won said that under the
    circumstances the British had a very high
    probability of victory. Those who thought the
    Gurkas had won said that was the most likely
    outcome under the circumstances, and so forth.
    (Based on data of Fischhoff, 1975)

78
  • Figure 7.17c Mean estimates of the likelihood of
    four outcomes varied depending on what each group
    was told about the actual outcome. Those who
    thought the British had won said that under the
    circumstances the British had a very high
    probability of victory. Those who thought the
    Gurkas had won said that was the most likely
    outcome under the circumstances, and so forth.
    (Based on data of Fischhoff, 1975)

79
  • Figure 7.17d Mean estimates of the likelihood of
    four outcomes varied depending on what each group
    was told about the actual outcome. Those who
    thought the British had won said that under the
    circumstances the British had a very high
    probability of victory. Those who thought the
    Gurkas had won said that was the most likely
    outcome under the circumstances, and so forth.
    (Based on data of Fischhoff, 1975)

80
Reconstructing Past Events
  • The false or recovered memory controversy
  • Reports of long-lost memories, prompted by
    clinical techniques, are known as recovered
    memories. Often these are memories of abuse that
    took place in early childhood.
  • There have been examples of accurate and
    inaccurate memories constructed through clinical
    techniques.
  • Psychological researchers want to know if it is
    likely that people will forget abusive or
    traumatic experiences.

81
Reconstructing Past Events
  • Memory for traumatic events
  • Sigmund Freud believed that it was possible to
    repress a painful memory, motivation or emotion,
    to move it from the conscious to the unconscious
    mind.
  • This idea is not well supported in research on
    memory and forgetting.

82
Reconstructing Past Events
  • Memory for traumatic events
  • Research indicates that it is possible to forget
    a traumatic event, but whether this happens
    depends on a number of factors age at the time
    of the event, reaction of family, and type of
    event.
  • Most people do not forget traumatic events if
    they happen later than age 3.

83
Reconstructing Past Events
  • Memory for traumatic events
  • Whether this happens because of repression or
    normal forgetting is unclear. People forget many
    pleasant and joyful events from early childhood
    as well.
  • Repression of traumatic events does not fit well
    with our understanding of the biological process
    of storing memory.
  • Emotional stimulation releases cortisol. The net
    effect is to improve the storage of memory.

84
Reconstructing Past Events
  • Suggestion and false memory
  • A false memory is a report that an individual
    believes to be a memory but that does not
    correspond to actual events.
  • Various studies have shown that it is possible by
    suggestion to implant memories for events that
    did not occur.
  • About a quarter of subjects in several studies
    were convinced that they had been lost as
    children after a researcher suggested it to them.

85
Reconstructing Past Events
  • Suggestion and false memory
  • Plausible events were more likely to be
    remembered, and the memories were somewhat vague,
    but these results were achieved after a single,
    brief suggestion.
  • Similarly, memory for details after watching a
    videotaped event can be altered or distorted by
    the use of leading questions.

86
Reconstructing Past Events
  • Children as eyewitnesses
  • Research with children can be ethically difficult
    because of their vulnerability.
  • We know that children forget rapidly and
    sometimes confuse fantasy and reality. Sometimes
    children witness crimes or other events about
    which we need information.
  • How do we work with children to tap their
    memories accurately? Can we do this?

87
Reconstructing Past Events
  • Children as eyewitnesses
  • Under proper conditions, children as young as
    three are able to make accurate reports of events
    that they have witnessed.
  • Young children can answer specific questions
    accurately.
  • If there is a delay between the event and the
    questioning, a child is more likely to give
    incorrect information.
  • If the question is not understandable, the child
    may give incorrect information.

88
Reconstructing Past Events
  • Children as eyewitnesses
  • Repetition of the question in the same interview
    session may yield two different answers.
  • Repetition of the question between spaced
    interview sessions may help the child remember
    better, which is important in court testimony.
  • Dolls and props may seem like helpful tools, but
    actually do not increase the accuracy of a
    childs recall or testimony.

89
Reconstructing Past Events
  • Children as eyewitnesses
  • The most effective strategies in interviewing
    young children are
  • Use of simple questions
  • Maintenance of a non-threatening atmosphere
    during the interview
  • Avoidance of suggestions or pressure
  • Schedule the interview as soon as is reasonable
    after the event

90
True, False, Maybe
  • Memories may or may not be reliable.
  • There is much evidence of forgetting and
    distortion. We use adaptive strategies for
    filling in the gaps reason and logic.
  • It is prudent to always consider the possibility
    that a seemingly clear memory is distorted or
    false.

91
Module 7.4
  • Amnesia

92
Amnesia After Brain Damage
  • Amnesia is a severe loss or deterioration of
    memory.
  • We can learn a lot about the different forms of
    memory by studying these cases.

93
Amnesia After Brain Damage
  • H.M.
  • In 1953, H.M. had his hippocampus and
    surrounding areas of the temporal lobes removed
    to control his intractable seizures.
  • Although his seizures did decrease dramatically,
    he experienced such dramatic memory impairment
    that such a surgery would never be attempted
    again.

94
  • Figure 7.19 (a) The hippocampus is a large
    subcortical structure of the brain

95
Amnesia After Brain Damage
  • H.M.
  • He experienced massive anterograde amnesia. He
    was unable to store any new memories. (It was
    1953 for the rest of his life.)
  • He had moderate retrograde amnesia. He could not
    remember many events that occurred between 1 and
    3 years before his surgery.
  • He did retain normal short-term memory functions.
  • His procedural memory was retained intact.

96
  • Figure 7.20 Brain damage induces retrograde
    amnesia (loss of old memories) and anterograde
    amnesia (difficulty storing new memories.)

97
Amnesia After Brain Damage
  • H.M.
  • What has been learned about the hippocampus from
    H.M.s tragic story?
  • All other things being equal, the more difficult
    a memory task is, the more it depends on the
    proper functioning of the hippocampus.
  • The hippocampus is important for remembering
    details.

98
Amnesia After Brain Damage
  • Frontal-lobe damage
  • The frontal lobes receive a great deal of input
    from the hippocampus. Damage to the frontal lobes
    causes some problems that are similar to
    hippocampal damage, and some unique problems as
    well.
  • Frontal lobe damage can occur as a result of
    stroke, head trauma, or Korsakoffs syndrome, a
    dementia that results from a deficiency of
    vitamin B1, brought on by chronic alcoholism.

99
Amnesia After Brain Damage
  • Frontal-lobe damage
  • The deficiency leads to loss and shrinkage of
    neurons in many parts of the brain, especially
    the thalamus and prefrontal cortex.
  • Multiple impairments of memory can result from
    this deterioration.

100
Amnesia After Brain Damage
  • Frontal-lobe damage
  • Typical symptoms of Korsakoffs syndrome include
  • Apathy
  • Confusion
  • Retrograde amnesia usually dating back to about
    15 years before the onset of the syndrome
  • Anterograde amnesia
  • Confabulation wild guessing mixed in with
    correct information, generated in an effort to
    hide gaps in memory.

101
Amnesia After Brain Damage
  • Implicit memory in amnesiac patients
  • Recall these two divisions of long-term memory
  • Explicit memory involves the recall of knowledge
    and events in which a person deliberately
    retrieves the answer and recognizes it as a
    correct one.
  • Your instructor asks you to name two
    psychologists associated with the principles of
    operant conditioning.

102
Amnesia After Brain Damage
  • Implicit memory in amnesiac patients
  • Implicit memory does not require recognition.
    The recall of activities stored in implicit
    memory seems effortless and unconscious.
  • You drive your car to school everyday but dont
    remember any details of the activities associated
    with driving.

103
Amnesia After Brain Damage
  • Implicit memory in amnesiac patients
  • Amnesiac patients such as H.M. show normal
    ability to use and store new implicit memory, but
    have impaired functioning of the factual memory
    activities of explicit memory.

104
Amnesia After Brain Damage
  • Implicit memory in amnesiac patients
  • NOR____
  • DET____
  • COR____
  • FRO____
  • Complete the words listed above.

105
Amnesia After Brain Damage
  • Implicit memory in amnesiac patients
  • If you wrote any of the following normal,
    detail, correct or cortex, frontal, there is a
    good chance that you were recalling words that
    appeared in the slides that preceded the task. It
    will be easy for you to remember this now that
    you know what happened.
  • Amnesiac patients will perform similarly on this
    task called priming they will complete the
    words in a similar manner, but they will never
    remember having read them previously.

106
Amnesia After Brain Damage
  • Implicit memory in amnesic patients
  • It is not uncommon for such a patient to learn a
    video game or other procedural task perfectly.
    However, the patient will never remember the
    event of being taught the game, or any individual
    session of playing it, even if that patient
    becomes highly skilled at the actual playing!

107
Concept Check
  • You have learned to play the guitar. What type of
    memory is involved in playing a song for your
    friends?

Implicit memory
108
Concept Check
  • You play guitar at a party for your friends.
    Later you remember the good time you had playing
    for them. What type of memory is involved in
    remembering this?

Explicit memory
109
Concept Check
  • Which of the following is an example of implicit
    memory?
  • a. There is a soap opera on TV at home. You
    dont get to watch it often, so you can never
    tell your friends the names of the characters.
    Two days later you are watching a late night TV
    program and you recognize one of the leading men
    as a guest.
  • b. You are sitting behind a couple at the movies
    who are having an animated discussion about
    skydiving. You are not paying attention to the
    content of their discussion. Later you
    spontaneously comment to your friends about how
    much fun it would be to learn to skydive.

b is implicit memory
110
Concept Check
  • What kinds of memory are most impaired in
    frontal lobe dementia patients and patients like
    H.M.? What kinds are least impaired?

Declarative or explicit memories are most
impaired. Procedural or implicit memories
are least impaired.
111
Infant Amnesia
  • Few people can remember events earlier than age 5
    or 6. Though children younger than this can
    describe earlier events in their own lives, these
    memories tend to fade.
  • The scarcity of early declarative memory is
    called infant amnesia or childhood amnesia. Why
    does this happen?

112
Infant Amnesia
  • Freud believed that this was a result of
    repression due to the emotional traumas of
    infancy. He offered no evidence for this theory.
  • Some cognitive psychologists believe that this is
    because early memories are nonverbal and later
    memories are verbal.
  • A biological explanation is that the hippocampus
    is not fully developed and doesnt store memories
    as completely.

113
Infant Amnesia
  • Another cognitive explanation is that lasting
    memories require a sense of self, and this
    typically doesnt develop fully until between 3
    and 4 years of age.
  • The theory of encoding specificity suggests that
    our retrieval cues in later life may not be
    adequate to recall early memories.
  • We are still trying to understand why these
    memories are not accessible.

114
Amnesia of Old Age
  • Some older people suffer from Alzheimers and
    other dementias that impair attention and memory.
  • Up until recently, scientists have typically
    overstated the vulnerability of healthy older
    people to memory loss.

115
Amnesia of Old Age
  • Most healthy people show little decline of memory
    in old age
  • Older adults show mild deficits on simple memory
    tasks.
  • Older adults show greater deficits on more
    complex tasks.
  • The attentional aspects of their working memory
    appear to be weaker older adults have more
    difficulty handling two tasks at once.

116
Amnesia of Old Age
  • People would like to know how to increase the
    chance of having good memory function later in
    life
  • A healthy lifestyle with regular exercise, good
    diet and limited use of alcohol.
  • An intellectually stimulating life may be related
    to good memory function as well.

117
Why do we forget?
  • Catastrophic loss of memory can only result from
    brain damage or disease.
  • Normal forgetting is a product of mechanisms
    that are usually adaptive.
  • It is probably true that remembering everything
    that happened would be overwhelming and
    debilitating for human beings.
Write a Comment
User Comments (0)
About PowerShow.com