CHAPTER 7
Human Memory
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Human Memory: Basic Questions
 How does information get into memory?
 How is information maintained in memory?
 How is information pulled back out of
memory?
 Encoding, storage, and retrieval
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Encoding:
Getting Information Into Memory
 The role of attention
 Focusing awareness
 Selective attention = selection of input
– Filtering: early or late?
 Divided attention
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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
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Enriching Encoding
 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
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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
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Sensory Memory
 Brief preservation of information in original
sensory form
 Auditory/visual – approximately ¼-second
– George Sperling (1960)
• Classic experiment on visual sensory store
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Short-Term Memory (STM)
 Capacity of storage – magical number 7 plus or
minus 2 (4 plus or minus 1?)
– Chunking – grouping familiar stimuli for storage as a single
unit
 Durability of storage – about 20 seconds without
rehearsal
– Rehearsal – the process of repetitively verbalizing or
thinking about the information
– Maintenance vs. elaborative rehearsal
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Short-Term Memory as
“Working Memory”
 STM not limited to phonemic encoding
 Loss of information not due only to decay
 Baddeley (1986) – 4 components of working memory
–
–
–
–
Phonological rehearsal loop
Visuospatial sketchpad
Executive control system
Episodic buffer
 Working memory capacity (WMC)
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Long-Term Memory
 Permanent storage?
– Flashbulb memories
 Debate: Are STM and LTM really different?
– Phonemic vs. semantic encoding
– Decay vs. interference-based forgetting
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How Is Knowledge Represented
and Organized in Memory?




Clustering and conceptual hierarchies
Schemas and scripts
Semantic networks
Connectionist networks and PDP models
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Retrieval: Getting Information
Out of Memory
 Using Cues to Aid Retrieval
 The tip-of-the-tongue phenomenon
–
–
A failure in retrieval
Retrieval cues
 Reinstating the Context of an Event
–
–
Context-dependent memory
State-dependent memory
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Memory as a Reconstruction – Bartlett
(1932)
• Many metaphors over time that don’t
acknowledge that memory is selective and
reconstructive
• Bartlett’s (1932) studies and reconstructive
memory
– British participants were asked to recall Native
American folktale
– Changed the structure and many elements
according to their own schemas
Memory as a Reconstruction -Loftus &
Palmer (1974)
 Original experiment
– N=45 American students; five conditions
– IV: the wording of the questions
(smashed/collided/bumped/hit/contacted)
– DV: the speed reported by the participants
 Findings
– The estimated speed was affected by the verb used
 Conclusion
– The verb conveyed an impression of the speed the car was
travelling and altered the participants’ perceptions
– Reporting bias or altered memory?
Memory as a Reconstruction: Loftus & Palmer
(1974)
 Follow-up study
– N=150 students; three conditions
– IV: the wording of the question (smashed/hit)
– DV: memory of broken glass?
 Findings
– The verb used impacted whether or not participants reported
seeing broken glass
 Conclusion
– Memory is easily distorted by the way questions are asked
and information gained after an event can become part of the
original memory, demonstrating that memory is a
reconstructive process
Forgetting: When Memory Lapses
 Measuring retention: the proportion of
material retained
– Recall
– Recognition
– Relearning
 How Quickly We Forget: Ebbinghaus’s
Forgetting Curve
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Why We Forget?
 Ineffective encoding
 Decay
 Interference
– Proactive
– Retroactive
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Retrieval Failure
 Encoding specificity
 Transfer-appropriate processing
 The Repressed Memories Controversy
– Support for recovered memories
– Skepticism regarding recovered memories
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Seven Sins of Memory: How
Memory Goes Wrong
 Sins of Omission
1. Transience
2. Absentmindedness
3. Blocking
 Sins of Commission
4. Misattribution
5. Suggestibility
6. Bias
7. Persistence
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In Search of the Memory Trace:
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 (neurogenesis)
• Long-term potentiation
 Anatomy
– Anterograde and retrograde amnesia
• Cerebral cortex, prefrontal cortex, hippocampus
• Consolidation
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In Pursuit of Memory
• Measuring how memory works generally
evaluates two forms of memories:
– Explicit memory: conscious, intentional recollection of
an event or of an item of information
– Implicit memory: unconscious retention in memory, as
evidenced by the effect of a previous experience or
encountered information on current thoughts or
actions
Contents of LTM
• Procedural memories: memories for the
performance of actions or skills (“knowing how”)
• Declarative memories: memories of facts, rules,
concepts, and events (“knowing that”)
– Semantic: general knowledge, including facts, rules,
concepts, & propositions
– Episodic: personally experienced events & the contexts in
which they occurred
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Improving Everyday Memory
 Engage in adequate rehearsal
 Distribute practice and minimize interference
 Engage in deep processing and transferappropriate processing
 Organize information
 Use verbal mnemonics
 Use visual mnemonics
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