Lecture 6: Mechanisms Underlying Recovering Memories

Forgetting Memories

• Forgetting is beneficial as it allows us to..

  • Achieve our goals

  • Function in society

  • Avoid being distracted by our past

• Learning and recalling info are active processes

  • Our memories are vulnerable to change

• Our memories can be reshaped by others saying things to us or just remembering things differently (e.g eyewitness testimony)

• Motivated Forgetting

  • Forgetting due to our motives/intentions

  • E.g forgot that you did bad on a test

  • Examined through Directed Forgetting Procedure

Directed Forgetting Procedure (2 Types)

• Being told to purposely forget something

• Item method directed forgetting

  • Learning Phase:

    • Encode words for a memory test

    • Immediately following each word

      • Remember or forget it

    • E.g "Plate" - remember, "Football" - forget (30 items)

  • Testing Phase:

    • Old/new recognition paradigm

      • Testing our memory based on words you saw during the learning session vs words you never saw/learned before in the learning session

  • Results:

    • To be forgotten words were dramatically impaired

    • To be remembered words were recalled quite well

      • Encoding Deficit:

        • Difficulty in being able to encode information, its not being transferred to your LTM so you just forget

• List method directed forgetting

  • Learning Phase:

    • Encode words for a memory test

    • Halfway through the list, ask participants to forget

      • Unexpected - that was a practice phase - not real

    • E.g "plate" "dog" "orange" FORGET (30 items)

  • Testing Phase:

    • Old/new recognition paradigm

  • Results:

    • Encode the items in the first half of the list

      • Didn’t know you weren't supposed to encode (remember)

    • No encoding deficits but rather retrieval deficits

      • Not sure what you were supposed to remember so its hard to recall them

      • Lower accessibility of those items

Forgetting our Autobiographical Memories?

• Episodic component: personal to you and memories that you’ve experienced

• Semantic Component: common knowledge about yourself (where you live, bday etc)

• Memory that happened to you in the past and you can remember the time and place and is significant

• Barnier et al (2007)

  • Learning Phase:

    • Generate a personal memory to each 24-cue word

    • Group A: forget 12 cue words, generate 12 new memories with new cue words

    • Group B: Remember 12 cue words, generate 12 new memories with 12 new cue words

  • Testing Phase:

    • List all memories from both lists

  • Results:

    • Reliable and strong directed forgetting effects

Natural Repressors

• How to push unwanted memories out of mind?

• Repressors

  • People that recall fewer negative events from their lives

• Myers, Brewin & Power (1998)

  • Directed forgetting procedure (list method)

  • Repressors & non-repressors studied 2 lists of words: pleasant and unpleasant

  • Results:

    • Repressors were better at using retrieval inhibition to block recall of unpleasant words

    • No difference between groups with blocking recall of pleasant words

• Repressors are natural suppressors

• Geraerts, Merckelbach, Jelicic & Smeets (2006)

  • Repressors: 7 day diary reporting a) positive b) negative intrusions after having supposed them in the lab

  • Over 7 day period, they reported highest number of negative intrusions

  • Results:

    • Short-term benefits

      • Fewer unwanted thoughts

    • Long-term consequences

      • Repressing emotions long term is not benefical as the info will eventually resurface

False Memories

• Memory resembles a synthesis of experience not a replay of a videotape

  • Were always actively reconstructing memories as things change

  • People can come to believe memories of experiences that never happened

    • E.g childhood abuse

• People use certain processes to form a coherent life narrative (temporal memory):

  • Reconstruction process

    • Involves piecing together fragmented memories to understand something that has happened in the past

  • Distance-based process

    • Taking a look at how we mentally place events in a timeline to help us understand how much time has passed

  • Familiarity

    • Because you're familiar with past events that have happened you believe it occurred at a specific time and place

• Post-Event Misinformation

  • After an event, you are told misinformation and your memory builds on it

Misinformation effect

• Memories are not good evidence as we will never remember every single detail

• Leading questions

  • Questions that lead you to answer a certain way that gives them a biased answer, implying a specific answer that influences someone to give a specific answer

• Loftus & Palmer (1974)

  • Showed participants a video of a speeding car that crashes into another car

  • Smashed 10% faster than contacted

  • Showed participants similar situation of 2 cars crashing

    • Asked them did they see A broken headlight vs did they see THE broken headlight

    • Definite question (the) = fewer idk responses and more recognition of event

  • Conclusions:

    • Minor changes to interview questions

      • Changes reported memory

    • Questions asked subsequent to an event can cause reconstruction

• Reconstructive Model (Braine, 1965)

  • Memories are stored as individuals details with varying degrees of association

  • Scripts can alter these memories

• Roediger & McDermott (1995)

  • Deese-Roediger-McDermott (DRM) Paradigm

  • Assess false memories among college students in the lab

Recovered Memories In The Lab

• Research has previously examined….

  • Clinical experience

  • Surveys of abuse survivors

  • College students

• Directed Forgetting - Terr (1991)

  • Sexually abused children cope by developing an avoidant encoding style

  • Able to disengage their attention from threatening cues

  • Impaired memory for these cues

• McNally, Clancy & Schacter (2001)

  • Encoding Phase:

    • Shown words on a computer screen

    • Cue to either remember or forget previous words

      • 3 categories of words: Trauma-Related, Positive, Neutral

  • Testing Phase:

    • Free recall task immediately after

    • Disregard previous "forget" or "remember" instruction

  • Results:

    • Normal memory functioning in the recovered memory group

    • Recalled to-be-remembered words more often than to-be-forgotten words regardless of word valence

    • Neither worse nor better memory for trauma-related words compared to control subjects (no abuse)

    • Recovered memories group did not show better ability to avoid encoding

    • Material related to abuse

• Creating False Memories

  • Explore if recovered memories might be false recollections

  • Suggestive therapeutic techniques

  • McNally's lab used DRM paradigm to elicit false memories in people with recovered memories