Cognitive Memory

• Encoding Failure


  Never entered the LTM
• Retrieval Failure


  Problems with storage, time passage, personal reasons, or the condition of the brain
• Interference


  Forgetting because other information gets in the way of what we want to recall
• Proactive Interference


  Old memories interfere with recall of new information
• Retroactive Interference


  New memories interfere with recall of old information
• Brown-Peterson Paradigm


  1. Participants given 3 consonants to remember

  2. Participants given a 3 digit number and asked to count backwards by threes

  3. After varying delays, participants asked to recall the 3 letters
• Trigrams were forgotten by 18 seconds due to retroactive interference of counting backwards
• Keppel & Underwood (1962)


  1. Replicated the Peterson and Peterson Task varying the same delay to recall

  2. Analysis done by trial number (1st trial, 2nd trial, 3rd trial, etc)

  3. Found support for proactive interference
• Retroactive interference from LTM


  The experimental group will remember less material from the tested list A compared to the control group
• Proactive Interference from LTM


  The experimental group remembers less materials from the tested list B than the control group
• Primary Effect


  Remember the first part
• Recency Effect


  Remember the last part
• Spacing Effect


  When you are given ample of time to rehearse
• Distinctiveness


  Unique or different
• Clustering


  Correlate with similar terms
• Serial position effect


  We remember the first and last items in a list best
• After a delay, we only remember the first items best
• Immediate recall: first and last items best
• Later recall: only the first items recalled well
• Serial Position curve


  We show superior recall of words close to the end of a list (the recency effect), pretty good recall of words close to the beginning of the list (primary effect), and relatively poor recall of words in the middle of the list
• Spacing effect


  We retain information better when we rehearse over time
• Participants who used spaced practice on memory tasks outperformed those using massed practice in 259 out of 271 cases
• Ebbinghaus (1885): spacing out periods of learning improves later recalls of the information
• When spacing is very short, people do better on immediate testing, but worse when tested later on
• Cramming might be better than nothing
• Autobiographical memory


  Memory of personal history
• Owens, Bower and Black (1979)


  • Nancy arrived at the cocktail party...
  • Nancy woke up feeling sick and she wondered if she were pregnant...
• The theme offered some background information and some retrieval cues, which increased recall
• However, the background info also led to more intrusions (memory for information not present), such as "the professor got Nancy pregnant"
• Schacter's "seven sins of memory"

  • Transience
  • Absent-mindedness
  • Blocking
  • Misattribution
  • Suggestibility
  • Bias
  • Persistence
• Eyewitness testimonies


  Episodic memory of specific event, often a crime
• Eyewitness memory, which is relied upon in the process of eyewitness identification, is thought to be fragile and easily distorted by information obtained post-event
• The single greatest cause of wrongful convictions nationwide, playing a role in more than 75% of convictions overturned through DNA testing
• Vulnerability of post event distortion

  Interference theory
• Verbal overshadowing of visual cue


  Cars smashed/hit
• Loftus and Palmer (1974)


  • Participants asked "how fast were the cars going when they smashed into each other?" vs "how fast were the cars going when they hit each other?"
• Problems with lineups


  • Assumption that perpetrator is in lineup
  • Distractor selection is also important
  • Police behavior may also influence
• Children's eyewitness memory


  • When a child is an eyewitness, they are typically asked questions to prompt information
  • Caution must be used to avoid "leading questions" or questions that suggest an answer
  • By the age of 10-11, children are no more susceptible than adults but younger children are more likely to be misled
  • Repeated questioning may lead a child to fabricate events that never happened
• Roediger & Mcdermott (1995)


  • Present a list of associated words, missing one "target" word
  • With immediate recall, participants tend to recall the non-presented target items
  • Participants report an actual memory for the item
• Garry, Manning, Loftus and Sherman (1996)


  • Participants complete Life Events Inventory (LEI)
  • Then are led through imagination exercises
  • Fill out LEI again
  • Imagining an event can increase a person's belief that the fictitious event actually happened