Transcript Oct. 24, 2007

Introduction to Psychology
Human Memory
Lecture Outline
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Encoding
Storage
Retrieval and Forgetting
Multiple memory systems
© 2002 John Wiley & Sons, Inc.
Memory
• Memory is the process by which we observe,
store, and recall information
– Memories may be visual, auditory, or tactile
• Memory processes may involve multiple
systems
– Conscious
– Automatic
© 2002 John Wiley & Sons, Inc.
Encoding
• Attention:
- Spotlight analogy
• Sensory detection
• Recognition of meaning
• Response selection
Levels of Processing
• Shallow processing - structural encoding
(capital letters, what color, etc…)
• Intermediate processing - phonemic
encoding (rhyming, homonyms, etc…)
• Deep processing - semantic encoding
(meaning or symbolism)
Facilitating Encoding
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Elaboration
Visual Imagery
Self Referential Encoding
Rehearsal and Over-learning
Deep and Transfer Appropriate processing
Distributed practice
Organize information
Mnemonic Devices
• Verbal mnemonics:
- acrostics, acronyms, and rhymes
• Visual mnemonics:
- link method, method of loci, keyword
- SQ3R
Encoding Specificity
• Encoding specificity principle: Idea that
ease of retrieval of a memory depends on
match of encoding with retrieval
– Poor recall if shallow learning is examined
using a deep processing technique
• Student who reads multiple choice items in test book
and then takes an essay exam will likely not do very
well
• State-dependent memory
2. Storage
• Assumes that memory consists of 3 stores:
– Sensory registers
• Iconic (visual)
• Echoic (auditory)
– Short-term memory (STM)
– Long-term memory (LTM)
© 2002 John Wiley & Sons, Inc.
The Information Processing
Model of Memory
© 2002 John Wiley & Sons, Inc.
Characteristics of STM
• STM is a variant of memory that is of limited
duration:
– Information in STM fades after 20-30 seconds (without
rehearsal)
• STM has limited capacity storage
– STM capacity is about 7 items of information
• Capacity is constant across cultures
• STM Involves rehearsal
– Maintenance: information is repeated
– Elaborative: information is related to other knowledge
© 2002 John Wiley & Sons, Inc.
Working Memory
• Working memory is temporary storage and
processing of information used to
– solve problems
– respond to environmental demands
– achieve goals
• Working memory may consist of three modules
– Visual Memory Store
– Verbal Memory Store
– Central Executive
© 2002 John Wiley & Sons, Inc.
Working Memory Stores
• Visual memory store
– A temporary image (20-30 sec) that provides information
about the location and nature of objects
• Verbal memory store
– Involves storage of verbal items
• Limited capacity
• Shallow: Items are processed in order of presentation and are
subject to interference
• Working memory stores are independent
– Brain damage may alter visual but not verbal
© 2002 John Wiley & Sons, Inc.
LTM
• LTM refers to the representations of facts, images,
actions, and skills that may persist over a lifetime
• LTM involves retrieval of information
• LTM is theoretically limitless in capacity
• The serial position curve supports the existence of
STM versus LTM
– Primacy effect reflects LTM
– Recency effect reflects STM
© 2002 John Wiley & Sons, Inc.
The Serial Position Curve
Recalled from
STM
Recalled from
LTM
(Figure adapted from Atkinson & Shriffrin, 1968)
© 2002 John Wiley & Sons, Inc.
Working Memory and LTM
• Evidence supporting a distinction between
working memory and LTM
– Working memory is easily accessed, but is limited in
capacity
– Neurological studies in which brain damage impairs
memory
• LTM impairment: person shows normal working memory,
but cannot transfer information to LTM
• Working memory deficit: person has a memory span of 2
digits, but normal LTM
– Chunking: LTM information is used to increase item
size in working memory (e.g. IBM, USC, CIA)
© 2002 John Wiley & Sons, Inc.
Functional Aspects of Memory
• Recall for information
may be a function of
our interest in the
information:
– Men show better recall
for workbench
construction details than
details on how to make
a shirt…
© 2002 John Wiley & Sons, Inc.
Networks of Association
• LTM is organized in clusters of information
that are related in meaning
– The network is composed of interconnected nodes
– A node may contain thoughts, images, smells,
emotions, or any other information
– Mnemonic devices allow one to add concepts to
existing networks
© 2002 John Wiley & Sons, Inc.
An Example of Interconnected
Nodes
© 2002 John Wiley & Sons, Inc.
Varieties of LTM
• Declarative memory
– Semantic: “generic” knowledge of facts
– Episodic: memories of specific events
• Autobiographical
• Procedural memory: for skills
• Explicit memory: Conscious retrieval of information
– Recall versus recognition
• Implicit memory: Skills, conditioned learning, and
associative memory
© 2002 John Wiley & Sons, Inc.
Repressed Memories
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Retrieval failures
Motivated forgetting
Denial
Repression
Psychogenic amnesia
• False Memory Syndrome
“Seven Sins of Memory”
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Memories are transient (fade with time)
We do not remember what we do not pay attention to
Our memories can be temporarily blocked
We can misattribute the source of memory
We are suggestible in our memories
We can show memory distortion (bias)
We often fail to forget the things we would like not
to recall (persistence of memory)
© 2002 John Wiley & Sons, Inc.