W5 Forgetting (process & motivated) ✅ Flashcards
What are the two types of forgetting?
- Incidental Forgetting: occurs without the intention to forget
- Motivated forgetting: purposefully diminish access to memory (e.g., unwanted memories)
What is meant by superior autobiographical memory?
- Uncontrollable remembering
- Feels as though the person relives the events they
remember - Remembering is “automatic”, effortless, and not under conscious control
- Cannot forget unpleasant memories
- Memories can be distracting
What is the forgetting curve?
Rate of Forgetting: increases as time progresses BUT the rate is different
=> Ebbinghaus studies
Forgetting curve:
- Logarithmic relationship
- Forgetting rapid initially
- Less additional forgetting at longer intervals
What are the rate for forgetting public events & personal events (episodic), and knowledge (semantic)?
- Public events:
Study: 14,000 Ps completed an online study of recall and
recognition for 40 events
Results: Similar to Ebbinghaus forgetting
curve
-> Recall: steep initial drop then slower forgetting rate
-> Recognition for same events was less affected
- Personal events:
Study: 400 US high-school graduates were tested on recalling and recognising
names of classmates after delays of up to 30 years
Result: similar to Ebbinghaus forgetting curve
-> Recognition of classmates’ faces/names remained intact
-> Recall a name when given a person’s pictures was extensively impaired - Knowledge:
Study: Explored forgetting of foreign language taught at university by testing graduates attending annual alumni reunion
Results:
-> Forgetting levels out after a period of 2 years
-> Little forgetting after this
period
Conclusion: recall is worse after delays than recognition, implies the distinction:
1. Availability: no longer have a memory trace
2. Accessibility: stored but not accessible
Factors that discourage forgetting?
- Testing/generation effect: repeated attempt to retrieve
- Not all memories are equally vulnerable to forgetting
- Jost’s law: older memories are more durable and forgotten less rapidly
than newer memories
-> new memories are initially more vulnerable to disruption/distortion until they are consolidated
HOWEVER: incomplete or inaccurate retrieval may lead to memory distortions
What is meant by the consolidation and reconsolidation cycle?
- Consolidation: The process that transforms new memories from a fragile state (easier to disrupt), to a more permanent state (resistant to disruption)
- Reconsolidation: The process by which a consolidated memory restabilises again after being reactivated by reminders (after retrieval).
-> During this, vulnerable to disruption again
What are the causes of incidental forgetting?
Trace decay AND correlations of time.
- ## Trace decay – memories weaken due to passage of time.
- Correlations of time, can be split into two factors:
- Context shifts: different cues are available now than the ones available at encoding.
- Interference: similar memories hinder retrieval
What is the supporting evidence for trace decay?
- Priming and familiarity are prone to decay,either:
- memory’s activations fade, BUT memory itself is intact
- memory itself & its activations degrade - Supporting evidence:
- Synaptic connections degrade and neurons die as time goes by -> memories can be lost in the same way
- Opposite can be true: neurogenesis -> neurological structure is remodeled
and its connections are gradually modified
-> Good for new learning
-> Bad for older memories retained in hippocampus - Problems with validity:
- Difficult to prove (behaviourally)
- Can’t control confounding factors (1. rehearsal & 2. interferences from new learning)
- Are the memory unavailable for simply inaccessible (cannot prove distinction)
What are the alternative factors of incidental forgetting?
- Contextual fluctuation:
- Incidental context differs more between retrieval and encoding over time (starts out as similar).
- Incidental context is less similar to the remote past than more recent past. - Interferences: Similar traces/memories impede retrieval.
- Difficult to discriminate.
- Similar memories accumulate more over time.
- Whenever the cue that can be used to access a memory becomes associated with other memories.
How does interference work and what is the supporting evidence for it?
Interference occurs due to the negative effect of having competitors (memories with shared activation cue).
=> increases with the number of competitors a target memory has
WHY? Competition Assumption:
- memories associated to a shared cue automatically impede retrieval when the cue is presented (activate all shared associated memories).
- The activated associates compete for access to consciousness.
What are the two types of interferences:
- Retroactive interference (RI): Introducing a new (second) memory impairs recall of a first memory
- Especially if similar & have shared cues
- More training on the second list = more first list impairment
—
Supporting study: rugby players asked to recall names of team played earlier in the season
-> Results: Forgetting was due to interference (newer rugby games) rather than decay (time). - Proactive interference (PI): The tendency of older memories to interfere with retrieval of recent experiences and knowledge
-> PI is more severe for recall than recognition
=> Both interferences can occur simultaneously/ depends on context
What are other causes of forgetting:
- Part-set cuing impairment: Recall is impaired due to a presence of some words (meant to act as cues/hints) from the OG studied list
=> Worse impairments with increasing numbers of cues.
HOW?
- Stronger association to cues instead of OG word list
- Competitions with non-cued words => worsen memory
—
2. Retrieval-induced forgetting (RIF): Selective/partial retrieval can harm recall of other
memories related to the retrieved item (compared to control)
-> Selective retrieval may contribute to more severe forgetting for information that is not practiced
=> Implications for learning
HOW? Retrieval (e.g. testing effect) can be beneficial for strengthening memories
BUT incomplete retrieval diminishes the benefits
-> stronger association with retrieved words so weaker with non-retrieved words
What are the 2 mechanisms of interference?
Mechanisms:
1. Associative blocking: A cue fails to elicit a target trace
due to stronger memory competitors.
-> Examples: tip-of-the-tongue (keep making incorrect responses), RI, part-set cuing, cue overload (more associates -> wrong answer)
- Associative unlearning: Associative bond linking a
stimulus to a memory trace will be weaken if made errors in retrieval
-> Examples: RIF & RI
What is the functional account of memory?
Answer: Forgetting to control retrieval in the face of competition
- Functional value -> active process
- Facilitates future retrieval attempts of practiced/ strengthened memories by inhibiting competitors
=> Serves goal-directed behavior and decision-making
Promote flexbility and generalisation of memory to guide rational decision-making
-> Forgetting allow individuals to exhibit flexible behaviour and generalize past events to new experiences
=> Represent and investment in a more optimal mnemonic strategy (cognitive efficiency)
