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Chapter 7: Human Memory
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Human Memory: Basic Questions
EncodingHow does information get into memory?StorageHow is information maintained in memory?RetrievalHow is information pulled back out of memory?
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Figure 7.2 Three key processes in memory
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Encoding: Getting Information Into Memory
• The role of attention
• Focusing awareness
• Selective attention = selection of input– Filtering: early or late?
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Figure 7.3 Models of selective 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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Figure 7.4 Levels-of-processing theory
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Figure 7.5 Retention at three levels of processing
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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
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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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Figure 7.7 The Atkinson and Schiffrin model of memory storage
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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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Figure 7.8 Sperling’s (1960) study of sensory memory
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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
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Figure 7.9 Peterson and Peterson’s (1959) study of short-term memory
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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
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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
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How is Knowledge Representedand Organized in Memory?
• Clustering and Conceptual Hierarchies
• Schemas and Scripts
• Semantic Networks
• Connectionist Networks and PDP Models
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Retrieval: Getting InformationOut 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
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Forgetting: When Memory Lapses
• Retention – the proportion of material retained– Recall – Recognition – Relearning
• Ebbinghaus’s Forgetting Curve
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Figure 7.16 Ebbinghaus’ forgetting curve for nonsense syllables
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Figure 7.17 Recognition versus recall in the measurement of retention
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Why Do We Forget?
• Ineffective Encoding
• Decay theory
• Interference theory– Proactive– Retroactive
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Figure 7.19 Retroactive and proactive interference
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Figure 7.20 Estimates of the prevalence of childhood physical and sexual abuse
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Retrieval Failure
• Encoding Specificity
• Transfer-Appropriate Processing
• Repression– Authenticity of repressed memories?– Memory illusions– Controversy
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Figure 7.22 The prevalence of false memories observed by Roediger and McDermott (1995)
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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
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The Physiology of Memory
• Anatomy– Anterograde and Retrograde Amnesia
• Cerebral cortex, Prefrontal cortex, Hippocampus,• Dentate gyrus, Amygdala, Cerebellum
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Figure 7.23 The anatomy of memory
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Figure 7.25 Retrograde versus anterograde amnesia
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Are There Multiple Memory Systems?
• Declarative vs. Procedural
• Semantic vs. Episodic
• Prospective vs. Retrospective
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Figure 7.26 Theories of independent memory systems
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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