Dr. Anne Cybenko University of Dayton Research Institute

“The Innocents” Taryn Simon

 There have been 289 exonerations in the US ◦  Over 70% of those have been due at least in part to a mistaken identification  It’s a unique situation that tests human memory and decision making

CORRECT IDENTIFICATION FALSE IDENTIFICATION Picking Cotton

 This guy commits a crime and someone witnesses it.

 Police get a description from the witness He was about 6’ tall, brown hair, brown eyes, no facial hair…

 Police find a suspect who may be: Guilty or Innocent

 Witness is shown a lineup that is either Perpetrator Present Perpetrator Absent

Perpetrator PresentPerpetrator Absent Picks the suspect CORRECT IDENTIFICATION Bad guy goes to trial FALSE IDENTIFICATION Innocent guy goes to trial Picks a foil FOIL PICK Bad guy may go free FOIL PICK Innocent guy may go free Rejects the lineup FALSE REJECTION Bad guy may go free CORRECT REJECTION Innocent guy may go free Type of Lineup Witness’s Decision

 Mostly undergraduate participants  Participants watch a mock crime (video or live)  Participants usually give a description  Filler task  Presented with a lineup  Make an Identification

 Witness interview techniques  Child interview techniques  Showups  Foil selection  Lineup Presentation  Lineup Instructions  Multi-modality lineups  Double-blind lineups

 Simultaneous or Sequential Lineups  Accuracy and Response Time  Verbal Overshadowing Effect  Interference Theory

I am going to show you six photographs. Please look at all six photographs before making any comment. The person who committed the crime may or may not be among those shown in the photographs you are about to see. If you recognize any of the persons in the photographs as the suspect, go back and pick out the person you recognize. If you recognize any of the persons please do not ask me whether your choice was ‘right’ or ‘wrong’, as I am prohibited by law from telling you.

SAN BERNARDINO COUNTY SHERIFF PHOTO LINE-UP

I am going to show you some photographs. The person who committed the crime may or may not be among those shown in the photographs you are about to see. If you recognize any of the persons in the photographs as the suspect, please tell me and we will stop the lineup. If you recognize any of the persons please do not ask me whether your choice was ‘right’ or ‘wrong’, as I am prohibited by law from telling you.

SAN BERNARDINO COUNTY SHERIFF PHOTO LINE-UP

DecisionPP Simultaneous PP Sequential PA Simultaneous PA Sequential Suspect ID Foil ID Reject Lindsay & Wells (1985)

 Results depend on: ◦ Similarity of the innocent suspect to the perpetrator ◦ Innocent suspect position in the sequential lineup  (Clark & Davey, 2001)

Decision PP Simultaneous PP Sequential #2 PP Sequential #4 PA Simultaneous PA Sequential #2 PA Sequential #4 Suspect Foil Reject Innocent suspect is medium similarity to perpetrator Decision PP Simultaneous PP Sequential #2 PP Sequential #4 PA Simultaneous PA Sequential #2 PA Sequential #4 Suspect Foil Reject Innocent suspect is high similarity to perpetrator

 The Mecklenburg Report (2006) Simultaneous (N = 319) Sequential (N = 229) Suspect Foil Reject

 Absolute vs relative decision making

 WITNESS model (Clark, 2003) to generate predictions  Perpetrator is represented as a vector of features, P.  Memory of the perpetrator (M): ◦ Feature j of P is stored correctly in M with probability a. ◦ Feature j of P is stored incorrectly in M with probability 1 – a.  Innocent suspect and foils: ◦ Feature j matches the perpetrator with probability s ◦ Feature j mismatches the perpetrator with probability 1 – s.  Match each lineup member to memory (M). ◦ m(L 1,M), m(L 2,M), …, m(L 6,M) (for six person lineup)  Apply decision rule to make a decision. Model-Based Predictions

◦ Best Above Criterion (BAC): A witness identifies the best matching lineup member if the match to memory is above criterion. (Absolute judgment) ◦ Relative Difference Model (RD): Best matching lineup member is identified if the difference between the best match and the next-best match is above a difference criterion. (Relative judgment)

 Dunning & Perretta (2002)  Four eyewitness studies using a combination of videotaped and live crimes. Measured response time and accuracy

 Witnesses making their ID’s faster than seconds were nearly 90% accurate  Witnesses that took longer than 12 seconds were 50% accurate  Automatic vs Deliberative processes StudyNAccurateInaccuratet ** * * ** * p<.05 ** p<.01 Study 1 participants had think aloud task

 Optimal response time changes with: ◦ An increase in retention interval (Brewer et al., 2006) ◦ An increase in the size of the lineup (Brewer et al., 2006) ◦ Confidence of the witness (Weber et al., 2004) ◦ Age (Weber et al., 2004)

 Verbalizing the appearance of previously seen visual stimuli impaired subsequent recognition performance

 Experiment 1 ◦ Does describing a perpetrator affect ones ability to identify him? DescriptionNone Correct ID Foil ID Rejection.25.14

 Experiment 3 ◦ Do these results apply to all stimuli that are difficult to describe? DescriptionVisualizationNone Correct ID Foil ID

 Experiment 5 ◦ Does this pattern of results change if there’s a limited amount of time to ID the suspect? DescriptionNone Unlimited Recognition Second Recognition.73.76

 Meta-analysis on 29 published and unpublished verbal overshadowing studies  Zr = -.12, a small but significant negative effect of verbal overshadowing

 Long delay between description and ID (Finger & Pezdek, 1999)  More than 1 trial (Fallshore & Schooler, 1995; Houser et al., 1997; Melcher & Schooler, 1995)  Following re-presentation of visual stimulus (Schooler et al., 1996)  When a cognitive interview is used (Finger & Pezdek, 1999; Meissner et al., 2001)

 Availability assumption ◦ Visual representation remains available in memory despite the temporary verbal impairment  Modality mismatch hypothesis ◦ Competing representations in memory from different modalities

 Proactive interference: When information that is presented BEFORE a target event interferes with the memory for that target event  Retroactive interference: When information that is presented AFTER a target event interferes with the memory for that target event  Retroactive interference is stronger than proactive interference (Schemeidler, 1939; McGeoch and Underwood,1943; Melton and Von Lacrum, 1941) 40

 Changed-trace hypothesis: Outside information interferes with target information because it changes the memory trace of the target information.  Multiple-trace hypothesis: Outside information interferes with target information because it creates a separate memory trace that is recalled instead of the target trace. 41

 Argued that the Loftus et al. results could have been due to 2 other issues: ◦ Original stimulus never encoded ◦ Remembered both, trusted/responded with the one from the narrative 42

 Participants were presented with slides depicting a maintenance man enter an office, fix a chair, then steal $20.  4 Critical items within the slides ◦ tool (hammer, wrench, or screwdriver) ◦ soda can (Coke, 7-up, or Sunkist) ◦ coffee jar (Folgers, Maxwell House, or Nescafe) ◦ magazine (Glamour, Vogue, or Mademoiselle)  Participants presented with written account of what they just saw. This written account contained misinformation for 2 of the items. 43

 Two types of tests: ◦ Traditional Recognition Test: Target vs. Interfering  Saw Coke, read about 7-up, Test: Coke or 7-up ◦ Modified Recognition Test: Target vs. Novel  Saw Coke, read about 7-up, Test: Coke or Sunkist  Traditional Recognition test – Picked 7-up  Modified Recognition test – Picked Coke  Participants could not have picked Coke in the modified test if reading about 7-up changed their memory trace 44

 Replicated McCloskey and Zaragoza (1985) with 2 changes  Gave either incorrect or neutral information in the recap of the slides (“7-up” or “soda” )  Test was in the form of open ended questions: “The key to the desk was next to a ____ can?”  participants performed equally well on the recall tests  If the misinformation really changed the memory trace, participants should have performed considerably worse on the recall test for the misinformation items. 45

 Replicated McCloskey and Zaragoza’s (1985) experiment  Testing was in the form of Yes/No statements: “Below the magazine rack there was a copy of Vogue magazine.”  Tversky and Tuchin asked about the critical item (the one from the slides), the misinformation item (the one from the summary of the slides), and the novel item (the one that did not appear at all)  Belli asked about the critical item, and the novel item.  Misleading postevent information reduced the "Yes" responses to the question about the original item.  T & T Subjects were equally good at rejecting the novel item  T & T Similar number of subjects responded yes to original item as responded yes to the misleading item.  Belli - misled subjects were better than control subjects at rejecting the novel item  Belli concluded memory trace was changed, T & T did not. 46

 McCloskey and Zaragoza’s results could have been a product of their stimuli having too many unique discernable features such that even if the trace was altered, some of those features would remain unchanged.  Used stimuli that were very similar to each other.  Conducted 10 Experiments 47

 Nature photographs  Cut in thirds 48 AA’ A”

 Variables between experiments: ◦ Proactive or Retroactive interference ◦ Presentation time ◦ Retention interval ◦ Number of stimuli 49

50 Target ListInterfering List Retention Test

 Found Retroactive interference when: ◦ Presentation time was long(7.5 and 10 seconds) ◦ Delay was short (3 – 15 minutes)  Did not find Retroactive Interference when ◦ Presentation time was short (4 seconds) ◦ Lots of stimuli (140 not 48) ◦ Delay was long (48 hours)  Did not find significant evidence of proactive interference under any conditions 51

 Participants tested in groups of 1-8  All stimuli presented on overhead  Responses were made on paper 52

 Experiment 1 was conducted to gather evidence for/against item specific retroactive and proactive interference in a modified recognition test.  Replicate Chandler’s results 53

 Participants: 60 Undergraduates  Materials: 48 Color Photographs of Nature Scenes. Each scene was divided into thirds (A, A’, A”) 54

AA”A’ 55

AA”A’ 56

57 Experiments 1 & 2 - Method Experiment 1  Math Phase  Study Phase  Interfering Phase  Math Phase  Test Phase  Interfering Phase  Study Phase  Math Phase  Test Phase Experiment 2

 Experimental Accuracy: M = 68.7, SD = 11.1  Control Accuracy: M = 75.8, SD = 8.8  t (31) = 4.682, p <.001, r =  Significant evidence of retroactive interference 58

 Experimental Accuracy: M = 71.88, SD = 9.65  Control Accuracy: M=72.77, SD =  t (27) =.486, p =.631, r =  No evidence of proactive interference 59

 See if the results of Chandler (1989, 1991) and Experiments 1&2 are found when the stimuli are words instead of images  Find support for/against the changed-trace and multiple-trace hypotheses 60

 Participants: 60 Undergraduates  Materials: 144 words from Van Overschelde, Rawson, and Dunlosky’s (2004) updated category norms. The 18 most common words from 8 categories(animals, colors, body parts, fruits, sports, clothing, countries, and car models) were used. 61

62 Experiments 3 & 4 - Method Experiment 3  Math Phase  Study Phase  Interfering Phase  Math Phase  Test Phase  Interfering Phase  Study Phase  Math Phase  Test Phase Experiment 4

 Experimental Accuracy: M = 80.51, SD =  Control Accuracy: M = 85.62, SD =  t (28) = 2.139, p =.013, r =  Evidence of retroactive interference was present 63

64  Experimental Accuracy: M = 76.14, SD =  Control Accuracy: M = 82.33, SD = 9.94  t (30) = 2.66, p =.013, r =  Evidence of proactive interference was present 64

 Find evidence for/against the Threshold Theory of Interference 65

 Participants: 39 Undergraduates  Materials: Same as Experiments 1 & 2 (nature pictures) 66

67 Experiments 5 & 6 - Method Experiment 5  Math Phase  Study Phase  Interfering Phase (4 or 1)  Math Phase  Test Phase  Interfering Phase  Study Phase  Math Phase  Test Phase Experiment 6

 Experimental (4) Accuracy: M = 67.78, SD =  Experimental (1) Accuracy: M = 72.25, SD =  Control Accuracy: M = 76.79, SD =  F(2,34) = 8.534, p =.001  Tukey test revealed that all groups are significantly different from each other. 68

 Experimental (4) Accuracy: M = 68.79, SD =  Experimental (1) Accuracy: M = 72.95, SD =  Control Accuracy: M = 75.05, SD =  F(2,34) = 8.534, p =.001  Tukey and paired samples t-tests: ◦ Control = Experimental (1) ◦ Control > Experimental (4) ◦ Experimental (1) > Experimental (4) 69

 Contrasts  Predictions: ◦ Control = Experimental (1) ◦ Control > Experimental (4) ◦ Experimental (1) > Experimental (4)  t (20) = , p =.047, r =

 Retroactive interference is found when the stimuli are pictures and words and when there is a single or multiple presentation of interfering information.  Proactive interference is only found when there are multiple presentations of interfering information. 71

 An interfering stimulus only interferes with a target stimulus IF the difference in strength between the memory trace of the interfering stimulus and the memory trace of the target stimulus crosses a threshold. 72

 Support for a modified version of multiple trace hypothesis  Threshold Theory of Interference is supported ◦ Evidence of proactive interference found with multiple presentations of interfering stimuli ◦ Evidence of retroactive interference ◦ No evidence of retroactive interference after 48 hours (Chandler, 1991) 73

 What determines the strength of the memory trace?  If Experiments 5 & 6 had more than 4 repetitions, would they cause even more interference? 74

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