PSC 1 Lecture 9: Lecture 9: Memory
Lecture 9: Memory
Memory
• Faye Treatser
o Oct 1985: Faye Treatser is raped
o Nov 8: Walter Snyder is questioned by police, fingerprinted and released
o Same day: Faye Treatser views a picture of Walter. She indicates he is not her
attacker.
o Nov 11: Faye sees Walter outside her apartment and identifies him as the attacker
o Jan 1986: Detective Shiftic summons Faye to the police station. Snyder is in the
waiting room. Faye ID's him again.
o "I am 100% sure"- Faye Treatser
o Court case took place
o DNA provides evidence it was not Snyder.
• Thus, human memory is fallible. We make mistakes.
Atkinson & Shiffrin 3 stage memory model
• Sensory memory
o Visual sensory memory is called iconic memory.
o Echoic memory is auditory sensory memory.
o Duration: About 1/2 second
o Capacity: ?
o No-tone and tone conditions
o No tone condition:
• accuracy- 50%
o Tone condition:
• Flash letters
• Play high, medium, low tone
• Subject reports: 100% accurate.
• Short tem memory
o Duration: 30 seconds, without rehearsal.
o Capacity: 7 plus or minus 2 "chunks"
• Primacy and Recency effects
o Give a string of digits
o Without rehearsal, digits from the beginning and end get remembered well, but not
the digits in the middle.
o Primacy: first items in the list are well remembered.
o Recency: if we test it as soon as we see it, items at the get remembered better than
those at the middle
o Primacy related to LTM and Recency related to STM.
• Long Term Memory
o Storage in LTM depends on rehearsal
o If you rehearse long enough, information gets stored and is refreshed by retrieval.
Working memory: Alan Baddeley
• Modern replacement of 3-stage Memory
• Replace STM with working memory
• More active system
• Central executive: decision making system
o What information to retrieve from LTM and what information to keep
• Phonological loop: keeps auditory information we might need in an active state.
• Visual spatial sketch pad: keeping the visual information we night need active.
• Central executive calls wither of the sub systems for information.
Long term memory
• Duration: until you die
• Capacity: unknown
• Problems for 3-satge model: time in STM does not mean information is stored in LTM.
Craig & Watkins 1973 study helped show the flaws in 3-stage model
