Memory II Reconstructive Memory ForgettingObserve this crime sceneMemory & GistWhat does a penny look like?Reconstructive nature of memoryVerbal labels can distort visual memoriesRemembering Objects from a Graduate OfficeMisinformation EffectExplaining Misinformation EffectOverwriting Hypothesis seems unlikelyRelevance to Criminal Justice SystemTraditional LineupIssues with lineupsImproved Lineup: Sequential PresentationUnbalanced lineupsImproving lineups: adding distinctive features to foils if target has distinctive featureBiased Lineup?Recovery of Lost Memories?Recovered memory vs. False MemoryCan false memories be implanted?Slide 21False Memory in the LabResultsAccuracy and ConfidenceSlide 25ForgettingForgetting FunctionsReminiscence BumpSlide 29Is there a purpose of forgetting?Algorithmic level explanations of forgettingExampleBlockingRetrieval Induced ForgettingBlocking or Suppression?Slide 36Inhibitory processes in memory?Memory IIReconstructive Memory ForgettingObserve this crime sceneMemory & Gist•Memory is better for meaningful significant features than for details of language or perception  gist is remembered better than detailWhat does a penny look like?Reconstructive nature of memory•Memory is often side-effect of comprehension–details can be filled in or reconstructed at retrieval time•Constructive approach to memory:–Memory = actual events + knowledge, experiences, expectationsVerbal labels can distort visual memoriesCarmichael, Hogan, & Walter (1932)Remembering Objects from a Graduate OfficeBrewer & Treyens (1981) chairdeskskullbooks(30% of subjects falsely remember books)Misinformation Effect•Memory for event can be influenced by information given after the eventElizabeth LoftusStudied sceneReconstructed memoryMisinformation: “Did another car pass the red datsun while it was stopped at the stop sign?Explaining Misinformation Effect•Three hypotheses–Overwriting•misleading information alters the memory trace–Source confusion / Misattribution•Perhaps the memory of the question is confused with the memory of the visual scene–Misinformation acceptance•Ss. believe the information in the postevent is true because questioner is a person of authorityOverwriting Hypothesis seems unlikely•McCloskey and Zaragoza (1985)•See event: yield sign•Receive misinformation, “as the car passed the...”misleading: “...stop sign?”nonmisleading: “...yield sign?”•Forced choice test: yield sign OR stop sign  35% drop in accuracy for misleading informationyield sign OR no U-turn  no difference in accuracy for misleading information(both groups much higher than chance)Relevance to Criminal Justice System•most obvious case–crime  study–picture of suspect (mugshot)  misinformation –Lineup  test•Eyewitness may recognize suspect from mugshot, not from crime scene.•Conclusions:–Do not let potential witnesses see suspects.–Interrogate without asking leading questionsTraditional LineupIdentify the person you saw earlier in the slidesIssues with lineups•Faulty eyewitness testimony is the single largest factor leading to false convictions (Wells, 1993)•Big problem:–Eyewitnesses often assume perpetrator is in lineupImproved Lineup: Sequential Presentation1 2 3 4 5 6 7 8Unbalanced lineups•Problem:•If distractors do not resemble the real perp, the one who comes closest may be picked.•Solution:–All distractor items need to fit description given by witness and be sufficiently diverse–No individual should stand outHowever.....lineups also lead to rightful convictionsImproving lineups:adding distinctive features to foils if target has distinctive featureZarkadi, Wade and Stewart (2009)Biased Lineup?46%(from Geoff Loftus)(A)(B)(C)(D)(E)(F)Recovery of Lost Memories?•Several lawsuits have relied on eyewitness testimony of repressed memories. These memories were “recovered” by family member or therapist•Claim: repression follows stress, but repressed material can be returned to consciousness with the removal of stress (e.g., Zeller, 1950, 1951; Merrill, 1954)•Problem: •Are these repressed memories or false memories (based on misinformation)?Recovered memory vs. False Memory•How do we know whether repressed memories are accurate? Hard to falsify•In some cases, traumatic information is misremembered or simply “made up”–Loftus has been involved in many cases–Points out problems of •hypnosis•suggestive questioning•dream interpretationsElizabeth LoftusCan false memories be implanted?Loftus and Pickrell (1995)You, your mom, and your brother went to Kmart. You were 5 years old. Your mom gave each of you some money to get a blueberry Icecream. You ran ahead to get into the line first, and lost your way in the store. Your mom found you crying to an elderly woman.Loftus and Pickrell (1995)False Memory in the Lab•Deese, Roediger, McDermott paradigm•Study the following words•Recall test .... •Recognition memory testUse ratings 1) sure new 2) probably new 3) probably old 4) sure old•TEST: BEDRESTAWAKETIREDDREAMWAKESNOOZEBLANKETDOZESLUMBERSNORENAPPEACEYAWNDROWSYSNORERESTCOFFEESLEEPResults•Critical lures (“sleep”) are words not presented but similar to studied words. These words are often falsely recalled (sleep: 61% of Ss.)•Recognition memory resultsproportion of items classified with confidence levels:confidence rating 4 3 2 1studied items .75 .11 .09 .05not studiedunrelated .00 .02 .18 .80critical lure .58 .26 .08 .08(e.g. “REST”)(e.g. “COFFEE”)(e.g. “SLEEP”)Accuracy and Confidence•False memory experiment shows sometimes confidence is high while accuracy is lowAccuracy and Confidence•Eyewitness testimony requires accuracy and confidence–“eyewitness testimony is likely to be believed by jurors, especially when it is offered with a high level of confidence” (Loftus, 1979)–That's him! I'm absolutely positive! I'll never forget that face as long as I live!”–Confidence ≠ Accuracy(Wells & Bradfield,1999; Loftus & Busey)ForgettingForgetting FunctionsForgetting over time as indexed by reduced savings. Ebbinghaus (1885-1913)Reminiscence BumpSchrauf & Rubin (1998)Enhanced memory for (episodic and semantic) facts of adolescence & young adulthood.Reminiscence BumpSchrauf & Rubin (1998)One explanation for reminiscence bump: encoding is better in periods of rapid change, followed by relative stability. Evidence from those who emigrated to