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Lecture Notes
Chapter 8

Several Cases

• Robert Cotton
  • 1984: assailant sexually assulted and robbed 2 women
  • 1985: Robert Cotton convicted based on:
    • Photo ID by one victim
    • Police lineup ID by other victim
    • Circumstantial evidence
  • Cotton convicted for life plus 54 years
  • 1995: DNA evidence exonerates Cotton
• James Newsome
  • Convicted of murdering Chicago grocery store owner
  • Three eye-witness accounts
  • 15 years later; new fingerprint technology proved Dennis Emerson, a known killer, guilty

• Misinformation effect
  • After the fact information transfer to memory
  • e.g., Loftus and Palmer: film of auto accident
    • How fast were cars going; "hit" vs. "smashed"
      • Smashed ---> higher speed and erroneous memory for broken glass
• Retrieval errors
  • Time elapsed, simultaneous or sequential presentation of photos, distinctiveness

• Not true

• Not true

Sensory
Short-term
Long-term

• Underlying neurophysiology

• Conceptual, information processing models

Iconic Memory

• Visual sensory memory
• Seeing before identification
• Sperling (1960)
  • 9 letters encoded
  • Greater than 1 second delay...50 percent recall

Echoic Memory

• Auditory sensory memory
• Necessary for speech recognition
• Darwin, Turvey and Crowder (1972)

"Magic 7" (+/-2)

Primacy effect

• Remembering items early in a list
  • Rehersal

• Remembering items late in a list
  • Still in short-term

Short-term Memory Limits

• Prevention of rehersal disrupts STM
• Show letter string
  • Backwards counting
• approx. 20 second limit
  

• Chunking
  • Rules
  • Patterns
  • 7 chunks
• Meaning
  • Organization

Phonological Working Memory

• Verbal information
• Storage of words
• Acoustic encoding
  • Conrad (1964)
    • List of letters presented visually
    • Write letters down
    • Acoustic errors: B for V, not F for T
  • Hintzman (1967)
    • Articulatory
    • Talking to self; subvocal articulation

Verbal Rehersal

• Memorization
• Speak words as reading them
• May or may not move lips
• Brain circuitry of speech?
• Braddeley (1986)
  • Auditory and articulatory systems cooperate
  • Feedback loops

Conduction Aphasia

• Left parietal lobe
  • Disruption of pathways
  • Wernicke's area (speech perception)
  • Broca's area (speech production)
• Deficit in phonological working memory
• Can talk and comprehend
• Bad at repeating what they've heard
  • Substitute other words
  • Usually get meaning right

Visual Working Memory

• Interplay of short-and long-term memory
• DeGroot (1965)
  • Chess board and pieces
  • Novices, experts
  • Random or "legal" placement of pieces
• Mental rotations
• Mental images
  • Tool construction

Short-term Memory Information Loss

• Transitory nature
• Memory decay
• Item displacement
  • New information...
    • Ignore new info or dump old info

• Sights, sounds, odours, tastes, textures
• Experiences

• Recall and encoding

Consolidation Hypothesis

• Transfer of short-term to long-term memory
• Sustained neural activity --> structural changes
• Bonk on the noggin'
• Retrograde amnesia
  • Loss of memory prior to injury
  • STM and LTM physiologically different
  • Transfer from STM --> LTM takes time

Levels of Processing Hypothesis

• Rehersal
  • Maintenance
    • Rote repetition
      • May not ---> LTM
  • Elaborative
    • Think about information
    • Forming associations
    • Context

Levels of Processing Hypothesis

• Shallow processing
  • Surface features; details
  • e.g., maintenance rehersal
• Deep processing
  • Semantic features; meaning
  • e.g., elaborative rehersal
• Knowledge, encoding, learning
• Retrieval
• Effortful processing
  • Rehersal; shallow or deep processing
• Automatic processing
  • Little or no attention
  • Usually non-complex information
• Encoding specificity
  • Gives content

Improving LTM

• Mnemomic systems
  • use already stored information
  • Provides organization
  • Retrieval of part helps retrieval of whole
• Method of loci
  • Items mentally associated with physical place
    • Pair words/concepts with place in "mental tour"
  • Peg-word
    • Memorized list of images needed
  • Narrative stories

Shakesperian Actors

• In Shakespeare's day...
• New play every 2-3 weeks...20 odd plays per year
• Next year, maybe 16 new plays, etc.
• Typecasting
  • Old man, young tough, etc.

Organization of LTM

• Form lost faster than meaning
• Episodic memory
  • Life experiences
  • Autobiographical
  • Context
• Semantic memory
  • Conceptual information
  • Data, facts, vocabulary, etc.
• Interaction between episodic and semantic

Explicit and Implicit Memory

• Explicit
  • Aware of the memory
  • "Declarative memory"
  • Level of processing important
• Implicit
  • "Unconscious", automatic
  • "Procedural memory"
  • Skills, controls behaviours
  • Retrieval cues important

Anterograde Amnesia

• Inability to form new long-term memories
• Implicit memories can still be formed
• Explicit, episodic memories prevented
• Recall of pre-injury memories fine
• Hippocampus

• Store 1000s of food pieces over the winter
• Do not reuse cache sites
• Recover most of the food on the same day it's cached

• Avian hippocampus (HP) on dorsal brain surface
• Avian and mammalian HP are homologues
• Lesion black-capped chickadee HP
  • Eliminates cache recovery

HP Differences: Food Storing/Non-food Storing Birds

• Food storing birds have bigger HP

Brown-Headed Cowbirds (BHC)

• Brood parasites
  • Lay eggs in other birds' nests
  • Related to red-winged blackbirds (RWB) and grackles (G)
  • Female BHC lays approx. 40 eggs/year
  • Spends morning searching for host nest
    • Lay egg next morning when host birds go to feed
  • Female BHC stores 10-20 possible nest sites
  • Male BHCs don't do this search
  • Data
    • Female BHCs have bigger HP than male BHCs
    • Non-brood parasites...no sex difference

Three Species of Cowbirds

• M. bonariensis (broad range parasite)
  • Big sex differences for HP
• M. rufoaxilaris (specialized parasite)
  • No sex differences for HP
  • Both sexes search for host nests
• M. badius (non-parasite)
  • No sex differences for HP

• None
• Both females and males cache
• Sex differences in hippocampus not coincidental
• Species-selective pressures produce differences

• Automatic
  • Appropriate stimulus
  • Implicit memories
    • Learned actions
  • Explicit memories

• "Tip-of-the-tongue" phenomenon
• Retrieval cues help
• Similar conditions

Length of Memory Storage

• Quite constant across time
• Initial level of learning important

• LTM recall not necessarily accurate
• Reconstruct "missing" information
  • Expectations, preferences, cultural factors
• Eyewitness testimony

• Interference as memory failure
• New memories can interfere with old
  • Jenkins and Dallenback (1924)
    • Recall after 8 hr sleep or 8 hr awake
• Retroactive interference
  • Recent info interferes with earlier info
• Proactive interference
  • Old info interferes with new info

• "Where were you when...?"
• e.g., Challenger disaster (1985)