Cognitive Processes PSY 334

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Cognitive ProcessesPSY 334

• Chapter 6 Human Memory Encoding and Storage

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Ebbinghaus

• First rigorous investigation of human memory
  1885.
• Taught himself nonsense syllables
• DAX, BUP, LOC
• Savings the amount of time needed to relearn a
  list after it has already been learned and
  forgotten.
• Forgetting function most forgetting takes place
  right away.

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Memory Models

• Atkinson Shiffrin proposed a three-stage
  model including
• Sensory store if attended goes to STM
• Short-term memory (STM) if rehearsed goes to
  LTM
• Long-term memory (LTM)
• No longer the current view of memory.
• Still presented in some books.

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The Three-Stage Model
Responses
Long-term memory
Attention
Sensation/perception
retrieval
Short-term (working) memory
Sensory store
Environment
encoding
Executive control processes
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Retention Times
Long-term memory
retrieval
Short-term (working) memory
Sensory store
Environment
encoding
1-3 seconds
15-25 seconds
1 sec to a lifetime
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Sensory Memory

• Holds info when it first comes in.
• Allows a person to extract meaning from an image
  or series of sounds.
• Sperlings partial report procedure
• A display of three rows of letters is presented.
• After it is taken away, a tone signals which row
  to report.
• Subjects were able to report most letters.

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Sperlings Partial Report
A medium tone signals the subject to report the
letters in this row
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Sperlings Results
Delay
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Kinds of Sensory Stores

• Iconic memory visual
• Bright postexposure field wipes out memory after
  1 sec, dark after 5 sec.
• Echoic memory auditory
• Lasts up to 10 sec (measured by ERP)
• Located in the sensory cortexes.

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Short Term Memory

• The original idea is that when info in sensory
  memory is paid attention to, it moves into short
  term memory.
• With rehearsal, it then moves into long term
  memory.
• STM has limited capacity, called memory span.
• Millers magic number (7 2)
• New info pushes out older info (Shepard)

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Shepards Results
Probability of recalling the target item
Number of intervening items
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Criticisms of STM

• Rate of forgetting seemed to be quicker than
  Ebbinghauss data, but is not really.
• Amount of rehearsal appeared to be related to
  transfer to long-term memory.
• Later it was found that the kind of rehearsal
  matters, not the amount.
• Passive rehearsal does little to achieve
  long-term memory.
• Information may go directly to LTM.

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Depth of Processing

• Craik Lockhart proposed that it is not how
  long material is rehearsed but the depth of
  processing that matters.
• Levels of processing demo.

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Working Memory

• Baddeley in working memory speed of rehearsal
  determines memory span. Articulatory loop
  stores whatever can be processed in a given
  amount of time.
• Word length effect 4.5 one-syllable words
  remembered compared to 2.6 long ones.
• 1.5 to 2 seconds material can be kept.
• Visuopatial sketchpad rehearses images.
• Central executive controls other systems.

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Word-Lenth Determines Forgetting
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Delayed Matching Task

• Delayed Matching to Sample monkey must recall
  where food was placed.
• Monkeys with lesion to frontal cortex cannot
  remember food location.
• Human infants cant do it until 1 year old.
• Regions of frontal cortex fire only during the
  delay keeping location in mind.
• Different prefrontal regions are used to remember
  different kinds of information.

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Delayed Matching to Sample
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Importance of Frontal Cortex

• In primates, working memory is localized to the
  frontal cortex.
• Delayed matching to sample task
• Monkeys are shown food that is then hidden.
• Later they are given a chance to locate it.
• Monkeys with frontal lobe lesions cannot do this
  task.

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Activation

• Activation how available information is to
  memory
• Probability of access how likely you are to
  remember something.
• Rate of access how fast something can be
  remembered.
• From moment to moment, items differ in their
  degree of activation in memory.

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Andersons ACT Model

• ACT Adaptive Control of Thought
• Moses Effect -- subjects shown the words Bible,
  animal and flood should recall Noah but recall
  Moses instead.
• When given the word flood they think of
  Mississippi or Johnstown but not Noah.
• Why? Recall is based on both baseline and
  activation from associated concepts.
• Moses and Jesus have higher baselines.

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The ACT Model
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Factors Affecting Activation

• How recently we have used the memory
• Loftus manipulated amount of delay
• 1.53 sec first time, then 1.21, 1.28, and 1.33
  with 3 items intervening.
• How much we have practiced the memory how
  frequently it is used.
• Andersons study (sailor is in the park)

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Spreading Activation

• Activation spreads along the paths of a
  propositional network.
• Related items are faster to recall.
• Associative priming involuntary spread of
  activation to associated items in memory.
• Kaplans dissertation cues to solving riddles
  hidden in the environment led to faster solutions.

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Associative Priming

• Meyer Schvaneveldt spreading activation
  affects how quickly words are read.
• Subjects judged whether pairs of related
  unrelated items were words.
• Judgments about related words were faster.

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Meyer and Schvaneveldt
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Practice and Strength

• The amount of spreading activation depends on the
  strength of a memory.
• Memory strength increases with practice.
• Greater memory strength increases the likelihood
  of recall.

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Power Function

• Each time we use a memory trace, it gradually
  becomes a little stronger.
• Power law of learning
• T 1.40 P-0.24
• T is recognition time, P is days of practice.
• Linear when plotted on log-log scale.

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Learning Curves
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Practicing Addition Problems
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Long Term Potentiation (LTP)

• Neural changes may occur with practice
• Long-term potentiation (LTP) in hippocampus.
• Repeated electrical stimulation of neurons leads
  to increased sensitivity.
• LTP changes are a power function.

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Neural Changes Mirror Behavioral Changes
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Neural Correlates of Encoding

• Better memory occurs for items with stronger
  brain processing at the time of study
• Words evoking higher ERP signals are better
  remembered later.
• Greater frontal activation with deeper processing
  of verbal information.
• Greater activation of hippocampus with better
  long-term memory.

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Activation in Prefrontal Cortex
Words activate left prefrontal cortex
Pictures activate right prefrontal cortex
Hemodynamic blow flow during brain activity
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Factors Influencing Memory

• Study alone does not improve memory what
  matters is how studying is done.
• Shallow study results in little improvement.
• Semantic associates (tulip-flower) better
  remembered than rhymes (tower-flower), 81 vs
  70.
• Better retention occurs for more meaningful
  elaboration.

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Elaborative Processing

• Elaboration embellishing an item with
  additional information.
• Anderson Bower subjects added details to
  simple sentences
• 57 recall without elaboration
• 72 recall with made-up details added
• Self-generated elaborations are better than
  experimenter-generated ones.

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Self-Generated Elaborations

• Stein Bransford subjects were given 10
  sentences. Four conditions
• Just the sentences alone 4.2 adjectives
• Subject generates an elaboration 5.8
• Experimenter-generated imprecise elaboration
  2.2
• Experimenter-generated precise elaboration 7.8
• Precision of detail (constraint) matters, not who
  generates the elaboration.

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Advance Organizers

• PQ4R method use questions to guide reading.
• 64 correct, compared to 57 (controls)
• 76 of relevant questions correct, 52 of
  non-relevant.
• These study techniques work because they
  encourage elaboration.
• Question making and question answering both
  improve memory for text (reviewing is better than
  seeing the questions first).

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Meaningful Elaboration

• Elaboration need not be meaningful other sorts
  of elaboration also work.
• Kolers compared memory for right-side-up
  sentences with upside-down.
• Extra processing needed to read upside down may
  enhance memory.
• Slamecka Graf compared generation of synonyms
  and rhymes. Both improved memory, but synonyms
  did more.

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Slamecka Grafs Results
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Mnemonics

• Method of Loci place items in a location, then
  take a mental walk.
• Peg-word System use peg words as a structure
  and associate a list of items with them using
  visualization.
• Create acronyms for lists of items.
• Convert nonsense syllables (DAX, GIB) into
  meaningful items by associating them with real
  words (e.g., DAD).

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This Old Man Song

• http//www.youtube.com/watch?v3cYf9vkW_xU
• http//www.totlol.com/watch/5d-6Q5V79CM/This-Old-M
  an/0/

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Pegword System

• 1 bun
• 2 shoe
• 3 tree
• 4 door
• 5 hive
• 6 sticks
• 7 heaven
• 8 gate
• 9 wine
• 10 -- hen

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Incidental Learning

• It does not matter whether people intend to learn
  something or not.
• What matters is how material is processed.
• Orienting tasks
• Count whether work has e or g.
• Rate the pleasantness of words.
• Half of subjects told they would be asked to
  remember words later, half not told.
• No advantage to knowing ahead of time.

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Awareness of Learning
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Flashbulb Memories

• Self-reference effect -- people have better
  memory for events that are important to them and
  close friends.
• Flashbulb memories recall of traumatic events
  long after the fact.
• Seem vivid but can be very inaccurate.
• Thatchers resignation
• 60 memory for UK subjects, 20 non-UK

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Self-Reference Effect

• Two explanations
• People have special mechanisms for encoding info
  relevant to themselves.
• Info relevant to the self is rehearsed more
  often.
• High arousal may enhance memory.
• Memory is better for words related to the self
  perhaps due to better elaboration.