Human Memory

Human Memory

1. Encoding

   • Encoding: Involves forming memory code, requires attention
   • Attention: Involves focusing awarness on a narrowed range of stimuli of events (selective attention critical to everyday functioning)
     • Cocktail Party Phenomenon: Suggests attention involves late selection, based on the meaning of input
     • Human brain can only effectively handle one attention-consuming task at a time
   • Levels of Processing: 3 Progressively Deeper Levels of Processing
     • Structural Encoding: Shallow processing, that emphasizes the physical structure of the stimulus
     • Phonemic Encoding: Emphasizes what a word sounds like
     • Semantic Encoding: Emphasizes the meaning of verbal input
       • Enriched by elaboration
         • Elaboration: Linking a stimulus to other information at the time of encoding
     • Levels-of-Processing Theory: Proposes that deeper levels of processing result in longer-lasting memory codes
   • Visual Imagery:
     • Imagery: The creation of visual images to represent the words to be remembered and to enrich encoding
     • Dual Coding Theory: holds that memory is enhanced by forming semantic and visual codes, since either can lead to recall
   • Self-Referent Encoding:
     • Defintion: Involves deciding how or whether information is personally relevant
     • Appears to enhance recall by promoting additional elaboration and better organization of information

2. Storage

   • Storage: Involves maintaining encoded information in memory over time
   • Sensory Memory: Preserves information in its original sensory form for a brief time, usually only a fraction of a second
     • In the case of vision people really perceive an afterimage rather than the actual stimulus. Ex: Sparkler at night
       • Memory trance in the visual sensory store decays in about 1/4 of a seconds
   • Short-Term Memory
     • STM Definition: A limited-capacity store that can maintain unrehearsed information for up to about 20 seconds
       • Can maintain info in short term indefinitely by engaging in rehearsal
         • Rehearsal: The process of repetitively verbalizing or thinking about the information
   • Capacity of Storage
     • George Miller (1956) "The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information"
     • Capacity of short term may be less than assumed (four plus or minus one)
     • Chunk: A group of familiar stimuli stored as a single unit
   • Long-Term Memory
     • LTM Definition: An unlimited capacity store that can hold information over lengthy periods of time
     • Flashbulb Memories: Usually vivid and detailed recollections of momentous events
   • Short-Term Memory as "Working Memory"
     • Working Memory: A limited capacity storage system that temporarily maintains and stores information by providing an interface between perception memory and action
     • Baddeley's Model: Consists of 4 Components
       • Phonological loop: At work when you use recitation to temporarily remember a phone number and is believed to facilitate the acquisition of language
       • Visuospatial Sketchpad: Permits people to temporarily hold and manipulate visual images. At work when you try to mentally rearrange furniture in bedroom
       • Central Executive System: Controls the deployment of attention, switching the focus of attention and dividing attention as needed, also coordinates the actions of the other modules
       • Episodic Buffer: Temporary, limited-capacity store that allows the various components of working memory to integrate info and that serves as an interface between working and long term memory
     • Working Memory Capacity (WMC): Refers to ones ability to hold and manipulate info in conscious attention
   • Knowledge Organization in Memory
     • Clustering: The tendency to remember similar or related items in groups
     • Conceptual Hierarchy: Multilevel classification system based on common properties among items
     • Schema: An organized cluster of knowledge about a particular object or event abstracted from previous experience with the object or event
     • Semantic Networks: Consists of nodes representing concepts, joined together by pathways that link related concepts
     • Spreading Activation: When people think about a word, their thoughts naturally go to related words
     • Connectionists (Parallel Distributed Processing (PDP)): Models assume that cognitive processes depend on patterns of activation in highly interconnected computational networks that resemble neural networks

3. Retrieval

   • Retrieval: Involves recovering information from memory stores
   • Tip-of-the-Tongue Phenomenon: The temporary inability to remember something you know, accompanied by a feeling that it's just out of reach
   • Encoding Specificity Principle (Tulving): Suggested your memory for info would be better when the conditions during encoding and retrieval were similar
   • Context clues often facilitate the retrieval of information
   • Misinformation Effect
     • Definition: Occurs when participants' recall of an event they witnessed is altered by introducing misleading post event information
       • Recall is often biased in the direction of higher-level schemas
   • Source and Reality Monitoring
     • Reality Monitoring: Refers to the process of deciding whether memories are based on external sources (perceptions) or internal sources (thoughts and imaginations)
     • Source Monitoring: Involves making attributions about the origins of memories
     • Source-Monitoring Error: Occurs when a memory derived from one source is misattributed to another source
     • Destination Memory: Involves recalling to whom one has told what

4. Forgetting

   • Can reduce competition among memories that can cause confusion
   • Adaptive
   • Ebbinghau's Forgetting Curve: Graphs retention and forgetting over time
   • Measures of Forgetting:
     • Retention: Refers to the proportion of material retained
     • Retention Interval: The length of time between the presentation of materials to be remembered and the measurement of forgetting
     • Recall: Measure of retention requires subjects to reproduce information on their own without any cues
     • Recognition: Measure of retention requires subjects to select previously learned info from an array of options
     • Relearning: Measure of retention requires a subject to memorize info a second time to determine how much time or how many practice trials are saved by having learned it before
   • Why We Forget
     • Psuedoforgetting: Usually due to lack of attention
     • Decay Theory: Proposes that forgetting occurs because memory traces fade with time
     • Interference Theory: Proposes that people forget info because of competition from other material
       • Retroactive Interference: Occurs when new information impairs the retention of previously learned info
       • Proactive Interference: Occurs when previously learned info interferes with the retention of new info
     • Retrieval Failure
       • The Encoding Specificity Principle: States the value of a retrieval cue depends on how well it corresponds to the memory code
       • Transfer-Appropriate Processing: Occurs when the initial processing of info is similar to the type of processing required by the subsequent measure of retention
     • Motivated Forgetting: The tendency to forget things one doesn't want to think about
     • Repression: Refers to keeping distressing thoughts and feelings buried in the unconscious
   • Seven Sins of Memory
     • Transcience: Simple weakening of memory over time
     • Absentmindedness: Refers to a memory failure that is often due to a failure to pay attention because we are preoccupied with other tings
     • Blocking: Temporary problem that occurs when we fail to retrieve an item of info such as someones name when we meet them
     • Misattribution: Assign a memory to the wrong source
     • Suggestibility: Our memory is distorted because of, for example, misleading questions
     • Bias: Refers to inaccuracy due to the effect of our current knowledge on our reconstruction of the past
     • Persistence: Involves unwanted memories and thoughts, in the extreme they can be associated with depression and post-traumatic stress disorder

5. Physiology of Memory

   • Neural Circuitry of Memory
     • One line of research suggests that memory formation results in alterations in synaptic transmission at specific sites
     • Long-Term Potential (LTP): A long-lasting increase in neural excitability at synapses along a specific neural pathway
   • Anatomy of Memory
     • 2 Types of amnesia:
       • Retrograde Amnesia: Involves the loss of memories for events that occurred prior to the onset of amnesia
       • Anterograde Amnesia: Involves the loss of memories for events that occur after the onset of amnesia
     • Consolidation: A hypothetical process involving the gradual conversion of information into durable memory codes stored in LTM

6. System and Types of Memory

   • Implicit Memory: Apparent when retention is exhibited on a task that does not require intentional remembering
   • Explicit Memory: Involves intentional recollection of previous experiences
   • Declarative Memory: System handles factual info
   • Nondeclarative or Procedural Memory: System houses memory for actions, skills, operations and conditioned responses
   • Episodic Memory System: Made up of chronological, or temporally dated, recollections of personal experiences
   • Semantic Memory System: Contains general knowledge that is not tied to the time when the info was learned
   • Prospective Memory: Involves remembering to perform actions in the future
   • Retrospective Memory: Involves remembering events from the past or previously learned info