12.+Memory+Errors

March 20, 2015
 * 12. Memory Errors**

Eyewitness memory Stress User's guide: How to change a memory Flashbulb memories Consolidation
 * Outline**

Clyde Charles Roy Criner The Problem
 * In March 1981, a 26 year old white female nurse suffered a brutal sexual assault
 * Clyde Charles was convicted of aggravated rape in June 1982
 * Case was taken up by the Innocence Project
 * A DNA test in 1999 eliminated him as a suspect
 * Arrested in 1985 and charged with the rape and murder of a 16 year old girl. Criner was convicted and sentenced to 99 years. In 1996, a DNA test proved it was not Criner's DNA. Dissatisfied with the results, the state decided to do its own test, which also came back negative.
 * District Attorney dismissed the tests and opposed a new trial. Texas Court of Criminal Appeals supported him.
 * Criner was pardoned by the governor and released four years later.
 * Why did the DA oppose a new trial?
 * An estimated 2,000-10,000 people a year are wrongfully convicted based on bad eyewitness testimony
 * About 300 false convictions have been overturned by DNA. 75% were due to faulty eyewitness testimony

Eyewitness testimony
 * Eyewitness Memory**
 * Jennifer Thompson remembered Ronald Cotton as the perpetrator instead of Bobby Poole ( [] )
 * Eyewitness memory can be faulty
 * Reimagining an event causes irreversible changes in your memory of the event
 * Picking the wrong face out of a lineup caused Jennifer Thompson to reimagine the event
 * How to increase accuracy of IDs
 * Accurate recognition memory is fast
 * Sequential lineups prevent false identifications
 * Simultaneous lineups make the witness ask...
 * Who is the best match?
 * Sequential lineups make the witness ask...
 * Does this person match?
 * Turns out simultaneous lineups might be better
 * Why do eyewitnesses get it wrong?
 * Leading questions
 * Faulty memory
 * Weapon focus
 * Own race bias
 * Etc.

Morgan et al. (2004): 500 military personnel participate in prisoner-of-war training. What might happen if you asked them again a week (or a month) later
 * Stress and Memory Encoding**
 * During training, 2 types of interrogation:
 * High-stress: physically confronted
 * Low-stress: tricked but not physically confronted
 * 1 day after release from camp, they viewed a 15-person live lineup and were asked to identify the person who was interrogating them yesterday for 40 minutes.
 * Results:[[image:morgan.png width="294" height="163" align="right"]]
 * Looked at two measures:
 * Correct identification
 * 30% high-stress made correct choice
 * 62% low-stress made correct choice
 * False identification
 * 56% high-stress made a false ID
 * 38% low-stress made a false ID
 * They'd continue to say the wrong thing, but they'd also get more confident.

Loftus and Pickerall (1995):
 * How to falsify a memory**
 * Asked subjects to remember 4 events reported by a relative.
 * 3 of the events had occurred, 1 had never occurred (e.g., being lost in the mall)
 * 25% of subjects recalled the fake event

Wade et al. (2002): Subjects saw pictures from childhood (one doctored). Interviewed 3 times, encouraged to generate details.
 * Participants recalled more false memories by the 3rd interview than they did at the 1st interview

Thinking a story actually happened to you is a failure of source memory.

Geraerts et al. (2008): Suggested a memory of getting sick after eating egg salad. A large minority believed it.
 * 4 months later:
 * Not only did they still believe the memory...
 * ...they ate significantly less egg salad.

Shaw & Porter (2015):
 * Goal: implant a false memory of an emotional event that occurred between ages 11-14
 * Emotional and criminal false events
 * False memories of theft, assault, and assault with a weapon. These false memories included police involvement.
 * Emotional but not criminal false events
 * False memories of animal attack, lost large sum of money, injury
 * Caregivers were interviewed, gave life story details, etc. Participants were ten interviewed 3 times within 1 week intervals in between.
 * During interview 1 participants were told 2 stories, which were supposedly true accounts taken from the caregiver interview:
 * A true event
 * A false event
 * Bag of tricks:
 * Make it believable
 * Participants asked to describe both events
 * Interviewer provides details:
 * A friend from the time who was supposedly present
 * City where it happened
 * Participant age at the time
 * Season when it happened
 * Social pressure
 * When struggling, they were told: "Most people can do it if they try hard enough."
 * When they came up with details, they were told "good," etc...
 * Vivid imagery
 * Context reinstatement
 * Guided imagery
 * Repeated practice
 * Three interviews with guided imagery
 * Practice visualization of the event each night at home
 * % of participants that formed false memories of...
 * Criminal events: 70%
 * Non-criminal events: 77%

Principles of memory modification
 * False Memory Recipe**
 * Reimagine
 * Vivid imagery helps
 * Every time you reimagine it, you slightly change the memory
 * Misleading helps
 * Wrong mug shot
 * Inaccurate initial memory because of stress
 * Misleading story (lost in mall)
 * Be in a suggestible state
 * Believe it's probably a real memory
 * Ruminate

Flashbulb memory - memory for the moment when you first learned about a surprising and emotional event
 * Flashbulb Memory**
 * These provide a unique way for memory researchers to collect data on highly emotional events

Greenberg (2004): President Bush's memories of how he found out about the terrorist attacks on 9/11 "provide a near-perfect example of false flashbulb memory." He talks about how he waiting outside a classroom when he saw an airplane hit the tower on TV, and thought it must have been a horrible accident.
 * There was no footage of the first plane crashing into the building (at least, not at that hour of the morning). But Bush remembered seeing it on TV.

Crombag, Wagenaar, & van Koppen (1996): An El Al jet crashed in Amsterdam in 1992. 10 months later they asked 193 Dutch people: "Did you see the television film of the moment the plane hit the apartment building?"
 * There was no footage, but 55% said they saw the footage

Flashbulb memories are often inaccurate
 * No one is intentionally messing with your memory, it's just wrong
 * Note: they aren't more inaccurate than everyday memories. It's all wrong!


 * Consolidation**
 * Events both before and after brain damage occurs are often forgotten.
 * Events in interval after damage tend to be forgotten because the brain can't form new memories while recovering.
 * Events in interval before damage tend to be forgotten for the same reason
 * Old memories are still being "consolidated" days (even months) after they were encoded.
 * The hippocampus is key
 * Until a memory is consolidated, it remains fragile


 * Meloni et al. (2014):
 * Rats underwent fear conditioning (ex: every time a light comes on, they receive a shock. So now when the light comes on, they freeze out of fear).
 * 24 hours later, reactivation (reconsolidating). Then expose them to xenon or air (xenon blocks consolidation).
 * After 48 hours, test if they freeze (shows that they remember),
 * Air: 70% still remember and freeze
 * Xenon: less than 30% freeze, meaning they forgot the memory[[image:reactivation.png width="321" height="188" align="right"]]
 * Follow-up: same experiment, but without reactivation
 * Xenon now has no effect


 * Reconsolidation: When you retrieve a memory it becomes "unconsolidated"
 * It needs to be reconsolidated
 * If you block reconsolidating you can "erase recently recalled memories."