Chapter 7 Human Memory

1
Chapter 7 Human Memory
2
Human Memory Basic Questions

• How does information get into memory?
• How is information maintained in memory?
• How is information pulled back out of memory?

3
Figure 7.2 Three key processes in memory. Memory
depends on three sequential processes encoding,
storage, and retrieval. Some theorists have drawn
an analogy between these processes and elements
of information processing by computers, as
depicted here. The analogies for encoding and
retrieval work pretty well, but the storage
analogy is somewhat misleading. When information
is stored on a hard drive, it remains unchanged
indefinitely and you can retrieve an exact copy.
As you will learn in this chapter, memory storage
is a much more dynamic process. Our memories
change over time and are rough reconstructions
rather than exact copies of past events.
4
Encoding Getting Information Into Memory

• The role of attention
• Focusing awareness
• Selective attention selection of input
• Filtering early or late?

5
Figure 7.3 Models of selective attention. Early-se
lection models propose that input is filtered
before meaning is processed. Late-selection
models hold that filtering occurs after the
processing of meaning. There is evidence to
support early, late, and intermediate selection,
suggesting that the location of the attentional
filter may not be fixed.
6
Levels of Processing Craik and Lockhart (1972)

• Incoming information processed at different
  levels
• Deeper processing longer lasting memory codes
• Encoding levels
• Structural shallow
• Phonemic intermediate
• Semantic deep

7
Figure 7.4 Levels-of-processing theory. According
to Craik and Lockhart (1972), structural,
phonemic, and semantic encodingwhich can be
elicited by questions such as those shown on the
rightinvolve progressively deeper levels of
processing, which should result in more durable
memories.
8
(No Transcript)
9
Enriching Encoding Improving Memory

• Elaboration linking a stimulus to other
  information at the time of encoding
• Thinking of examples
• Visual Imagery creation of visual images to
  represent words to be remembered
• Easier for concrete objects Dual-coding theory
• Self-Referent Encoding
• Making information personally meaningful

10
Storage Maintaining Information in Memory

• Analogy information storage in computers
  information storage in human memory
• Information-processing theories
• Subdivide memory into 3 different stores
• Sensory, Short-term, Long-term

11
Figure 7.2 Three key processes in memory. Memory
depends on three sequential processes encoding,
storage, and retrieval. Some theorists have drawn
an analogy between these processes and elements
of information processing by computers, as
depicted here. The analogies for encoding and
retrieval work pretty well, but the storage
analogy is somewhat misleading. When information
is stored on a hard drive, it remains unchanged
indefinitely and you can retrieve an exact copy.
As you will learn in this chapter, memory storage
is a much more dynamic process. Our memories
change over time and are rough reconstructions
rather than exact copies of past events.
12
Figure 7.8 The Atkinson and Shiffrin model of
memory storage. Atkinson and Shiffrin (1971)
proposed that memory is made up of three
information stores. Sensory memory can hold
information just long enough (a fraction of a
second) for a small portion of it to be selected
for longer storage. Short-term memory has a
limited capacity, and unless aided by rehearsal,
its storage duration is brief. Long-term memory
can store an apparently unlimited amount of
information for indeterminate periods.
13
(No Transcript)
14
Sensory Memory

• Brief preservation of information in original
  sensory form
• Auditory/Visual approximately ¼ second
• George Sperling (1960)
• Classic experiment on visual sensory store

15
Figure 7.9 Sperlings (1960) study of sensory
memory. After the subjects had fixated on the
cross, the letters were flashed on the screen
just long enough to create a visual afterimage.
High, medium, and low tones signaled which row of
letters to report. Because subjects had to rely
on the afterimage to report the letters, Sperling
was able to measure how rapidly the afterimage
disappeared by varying the delay between the
display and the signal to report.
16
Short Term Memory (STM)

• Limited capacity magical number 7 plus or minus
  2
• Chunking grouping familiar stimuli for storage
  as a single unit
• Limited duration about 20 seconds without
  rehearsal
• Rehearsal the process of repetitively
  verbalizing or thinking about the information

17
Figure 7.10 Peterson and Petersons (1959) study
of short-term memory. After a warning light was
flashed, the subjects were given three consonants
to remember. The researchers prevented rehearsal
by giving the subjects a three-digit number at
the same time and telling them to count backward
by three from that number until given the signal
to recall the letters. By varying the amount of
time between stimulus presentation and recall,
Peterson and Peterson were able to measure how
quickly information is lost from short-term
memory.
18
Short-Term Memory as Working Memory

• STM not limited to phonemic encoding
• Loss of information not only due to decay
• Baddeley (1986) 3 components of working memory
• Phonological rehearsal loop
• Visuospatial sketchpad
• Executive control system

19
Figure 7.11 Short-term memory as working
memory. This diagram depicts the revised model of
the short-term store proposed by Alan Baddeley
(1986), who views STM as a mental scratchpad or
temporary workspace. According to Baddeley,
working memory includes three components a
phonological rehearsal loop, a visuospatial
sketchpad, and an executive control system.
20
Long-Term Memory Unlimited Capacity

• Permanent storage?
• Flashbulb memories
• Recall through Hypnosis
• Debate are STM and LTM really different?
• Phonemic vs. Semantic encoding
• Decay vs. Interference based forgetting

21
How is Knowledge Represented and Organized in
Memory?

• Clustering and Conceptual Hierarchies
• Schemas and Scripts
• Semantic Networks
• Connectionist Networks and PDP Models

22
Figure 7.14 A semantic network. Much of the
organization of long-term memory depends on
networks of associations among concepts. In this
highly simplified depiction of a fragment of a
semantic network, the shorter the line linking
any two concepts, the stronger the association
between them. The coloration of the concept boxes
represents activation of the concepts. This is
how the network might look just after a person
hears the words fire engine. (Adapted from
Collins Loftus, 1975)
23
Retrieval Getting Information Out of Memory

• The tip-of-the-tongue phenomenon a failure in
  retrieval
• Retrieval cues
• Recalling an event
• Context cues
• Reconstructing memories
• Misinformation effect
• Source monitoring, reality monitoring

24
Forgetting When Memory Lapses

• Retention the proportion of material retained
• Recall
• Recognition
• Relearning
• Ebbinghauss Forgetting Curve

25
Figure 7.17 Ebbinghauss forgetting curve for
nonsense syllables. From his experiments on
himself, Ebbinghaus concluded that forgetting is
extremely rapid immediately after the original
learning and then levels off. However,
subsequent research has suggested that this
forgetting curve is unusually steep. (Data from
Ebbinghaus, 1885)
26
(No Transcript)
27
Why Do We Forget?

• Ineffective Encoding
• Decay theory
• Interference theory
• Proactive
• Retroactive

28
Figure 7.20 Retroactive and proactive
interference. Retroactive interference occurs
when learning produces a backward effect,
reducing recall of previously learned material.
Proactive interference occurs when learning
produces a forward effect, reducing recall of
subsequently learned material. For example, if
you were to prepare for an economics test and
then study psychology, the interference from the
psychology study would be retroactive
interference. However, if you studied psychology
first and then economics, the interference from
the psychology study would be proactive
interference.
29
(No Transcript)
30
Retrieval Failure

• Encoding Specificity
• Transfer-appropriate Processing
• Repression
• Authenticity of repressed memories?
• Controversy

31
The Physiology of Memory

• Biochemistry
• Alteration in synaptic transmission
• Hormones modulating neurotransmitter systems
• Protein synthesis
• Neural circuitry
• Localized neural circuits
• Reusable pathways in the brain
• Long-term potentiation
• Anatomy
• Anterograde and Retrograde Amnesia
• Cerebral cortex, Prefrontal Cortex, Hippocampus,
• Dentate gyrus, Amygdala, Cerebellum

32
Figure 7.24 Retrograde versus anterograde
amnesia. In retrograde amnesia, memory for events
that occurred prior to the onset of amnesia is
lost. In anterograde amnesia,memory for events
that occur subsequent to the onset of amnesia
suffers.
33
Are There Multiple Memory Systems?

• Implicit vs. Explicit
• Declarative vs. Procedural
• Semantic vs. Episodic
• Prospective vs. Retrospective

34
(No Transcript)
35
(No Transcript)
36
Improving Everyday Memory

• Engage in adequate rehearsal
• Distribute practice and minimize interference
• Emphasize deep processing and Transfer-appropriate
  processing
• Organize Information
• Use Verbal Mnemonics
• Use Visual Mnemonics

Launch Video
37
(No Transcript)
38
Figure 7.26 The serial-position effect. After
learning a list of items to remember, people tend
to recall more of the items from the beginning
and the end of the list than from the middle,
producing the characteristic U-shaped curve shown
here.
39
Figure 7.27 Effects of massed versus distributed
practice on retention. Children in the Underwood
(1970) study showed better recall of information
when practice sessions were distributed over time
as opposed to being massed together in one
session.
40
(No Transcript)