Memory Decay and Distortion 1 & 2 (wk 3) Flashcards
List three factors that can influence Memory between storage and retrieval
- Passage of time (forgetting)
- Intervening knowledge/experience (learning)
- Misinformation (Gaining incorrect information regarding an event
Eyewitness memory is …….
Reconstructive
Hermann Ebbinghaus
- Investigated memory scientifically and systematically exploring how info is stored in the brain and decays over time
- Studied this by presenting participants with nonsense syllables and then asked them to recall these after different time delays
- Results led to the formulation of the Ebbinghaus forgetting curve which suggests forgetting is a non-linear process
The Forgetting Function
Forgetting functions describe how accuracy or discriminability declines as the temporal distance from the event to be remembered increases.
This was one of Ebbinhaus’s findings in developing the forgetting curve
Describe how Memory becomes fragile in recall
Memory is formed through encoding and consolidation.
When we retrieve or recall information from our memory, it moves from a stable, consolidated format into a neurobiologically fragile state which is susceptible to change. As such, when memory is recalled and reconsolidated, the memory trace itself can change
What did Soren Kierkegaard say about Intervening Knowledge/Experience?
“Life is backwards, but must be lived forwards”
This stresses the idea that our memory guides our future actions, and that memory is continually being updated to integrate new and present knowledge
Snyder and Uranowitz 1978 Study on Intervening Knowledge/Experience and Memory
- Participants were presented with a case history about “Betty K”
- After one day or one week from reading the case history, participants were told that Betty was either straight or gay (or a control group was told nothing)
- Then participants’ memory for the case history was assessed
Findings showed the delay before intervening was unimportant but that participants made more label-consistent errors in recall than label-inconsistent errors.
Aka. Intervening knowledge (Betty’s sexuality) attributed for some error in the memory trace regarding the case history
Hindsight Bias
= When knowledge of current events, emotions, or outcomes, bias judgments, and the memory of processes leading up to those judgements.
(ie. I always knew he’d cheat on her)
- This is a product of intervening knowledge/experience infiltrating our memory trace
(eg. the more clues we get someone is a cheater, the more likely we are to think we always had doubts about them)
Hindsight bias can both influence our judgements and our memory for past events
Davis, Lopez, Koyama et al., 2005 study on Intervening Knowledge/Experience
Participants listened to an audio tape of a couple arguing
- Half the participants were told the couple subsequently broke up
- The other half were told the female was murdered, and her bf was a suspect in the murder
Participants were then tested on their memory for the audio tape
When told she was murdered, participants were more likely to accurately remember the threatening statements made by the male, however, were more likely to inaccurately recall aspects of the story (like he hit her and threatened her classmate etc)
(like being a liberal responder in a SDT with more hits and more false positives)
Misinformation and Memory
Misinformation is any information gained after a memory is laid down that was not part of the original event. (aka. Post event information)
Misinformation can reliably interfere with our memory trace
Elizabeth Loftus; Standard Misinformation Procedure
- Event (expose a participant to something)
- After some duration of time mislead the participant by planting inaccurate information
- After another duration of time interview the participant about the original event
eg. Watch red car in an accident –> ask “how fast was the blue car going” –> What colour was the car?
Misinformation Effect
Is a robust memory effect, in which misinformation becomes part of our memory trace
TWA 800 Flight as an example of memory inaccuracy
In the 1900’s TWA Flight 800 left New York and crashed shortly after near Long Island
There were no survivors in the crash but many eyewitnesses.
One eyewitness reported seeing something ‘hit’ the plane and media speculated it was a missile which caused the crash
Speculation in media and eyewitness reports were everywhere, until people were convinced they saw the missile hit the plane and believed when reports revealed the plane crashed due to a faulty fuel tank that the government were covering up a terrorist attack
What are three sources of misinformation in memory
- Media
- Other witnesses (co-witness discussions)
- Investigators (ie police)
Media as a source of misinformation ; Ei AI Crash, Amsterdam 1995
Shows how media can be both a good investigative tool but also a source of misinformation
- A plane crashed into an apartment at night and there was no video footage
- media speculated what could have happened
- in a survey 6 - 9 months after the crash 50% of people believed they had seen video footage of the crash
This shows how media reports are impactful as people can create memories for information they read
Media and Misinformation; Loftus and Banaji 1989
Showed participants a short video (4 mins) of a robbery and shooting
Then participants were exposed to either a TV report containing misinformation or no misinformation (that was either consistent or inconsistent with the informaiton in the original stimulus video).
Participants were asked to watch the TV report and evaluate the news caster before they were tested for memory on information in the original stimulus video.
Those exposed to a misinformation filled news caster video were more likely to incorporate misinformation . In fact 1/3 of misinformed participants incorporated the misinfo in their reports, whilst control responses were highly accurate