Week 4 Lecture 4 - forgetting Flashcards
What are the two types of forgetting?
incidental forgetting
motivated forgetting
What is incidental forgetting?
occurs without intention to forget
What is motivated forgetting?
purposefully diminish access to memory
What is superior autobiographical memory?
uncontrollable remembering
- feels like you are reliving the event
- uncontrollable and effortless
- can’t forget unpleasant memories
- distracting
Does forgetting increase over time?
yes
Does rate of forgetting increase over time?
no this is different
Who came up with the forgetting curve?
Ebbinghaus
What is the forgetting curve?
- logarithmic relationship
- initially rapid
- less additional forgetting at longer intervals
What did a study into forgetting public events find?
rate of forgetting is similar to that of the forgetting curve
recognition is less affected
What did a study into forgetting personal events find?
- recognitions of classmate names and faces was intact
- ppts could match up names with faces (unimpaired)
- recall of names when given a picture of a face was impaired (similar to the forgetting curve)
What did a study into forgetting knowledge find?
- forgetting levels out after 2 years with little forgetting after
- conducted on uni alumni
What is availability?
is item in the memory store?
What is accessibility?
is item accessible for retrieval?
Do both availability and accessibility denote forgetting?
yes
What are 2 factors that discourage forgetting?
- better learning at the beginning
- repeated attempts to retrieve
What can incomplete / inaccurate retrieval lead to?
memory distortions
Are all memories equally vulnerable to forgetting at all points in their history?
no
What is 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
What is consolidation?
process that transforms new memories from a fragile state to a more permanent state
What are 2 types of consolidation?
synaptic consolidation
systems consolidation
What is synaptic consolidation?
- structural changes in synaptic connections
- takes hours to days
- memories vulnerable until changes are complete
What is systems consolidation?
- gradual shift of memory from hippocampus to cortex
- memory componets (in cortex) replayed until linked
- takes months to years
- memories vulnerable for as long as they rely on hippocampus
What are 3 causes of incidental forgetting?
- trace decay
- context shifts
- interference
What is trace decay?
memories weaken due to the passage of time
What 2 things are especially prone to trace decay?
- priming
- familiarity
How does decay affect memories? Give 2 possible explanations
- a memory’s activations fade but the memory itself is intact
- the memory itself and its elements degrade along with its activity
What is the biological basis for trace decay?
synaptic connections degrade and neurons die –> memories fade in the same way
What is neurogenesis?
the growth of new neurons
neurogenesis remodelled structure and gradually modifies connections
What is this good and bad for?
- good for new learning
- bad for old memories (especially in the hippocampus)
is trace decay valid?
- behaviourally difficult to prove
- rehearsal and interference can’t be controlled
- memories unavailable or simply inaccessible?
What are correlates of time?
- forgetting may not be caused by the passage of time itself but by a correlate of time
What are contextual shifts?
different cues are available now than the ones available at encoding
How might similarities between encoding and retrieval context explain forgetting?
- contextual fluctuation
- incidental context differs more between retrieval and encoding over time
incidental context is less similar to the remote past then more recent past
What is interference?
similar memories hinder retrieval
Explain how interference can lead to incidental forgetting
- similar traces impede retrieval
- difficult to discriminate between them
- similar memories accumulate more over time
When does interference occur?
- whenever the cue that can be used to access a memory becomes associate with other memories
What is the competition assumption?
memories associated to a shared cue automatically impede retrieval when cue is presented
a cue activates all associations
Then what happens?
- the activated associates compete for access to consciousness
- competitors hinder access to target memory
What does interference occur due to?
the negative effect of having competitors
What is retroactive interference?
the introduction of new memory impairs recall of a first memory (especially if they are similar)
e.g., learning of a list of Spanish words then learning a list of French words
Give an example of a study showing retroactive interference
Baddeley and Hitch
rugby players study
new rugby games interfered with previous ones making them less accessible
What is Proactive interference?
- older memories interfere with retrieval of new experiences
- more severe for recall that recognition
What is part-set cuing impairment?
- providing hints may impede memory retrieval
- impairment increases as the number of cues provided increases
How does part-set cuing impairment work?
- presenting similar items as cues, strengths their association to the cue
- competition for non-cues increases –> memory worsens
What is retrieval induced forgetting?
- selective/partial retrieval can harm recall of other memories related to retrieved item
- selective retrieval may contribute to more severe forgetting for information that is not practiced / retrieved
What study supports retrieval induced forgetting?
crime scene investigations study
interrogating people about some stolen items impaired memory for related items
What are 2 types of interference mechanisms?
- associative blocking
- associative unlearning
What is associative blocking?
a cue fails to elicit a target trace because it repeatedly elicits a stronger competitor, leading people to abandon efforts to retrieve target
give some examples of associative blocking
- tip-of-the-tongue
- retroactive interference
- part-set cuing
- cue overload –> more associates, more likely a wrong answer to intrude
What is associative unlearning?
associative bond linking a stimulus to a memory trace is punished by weakening it after being retrieved in error
Difficult to demonstrate empirically
What are some examples of associative unlearning?
- retrieval-induced forgetting and retroactive interference
- competitors intrude at retrieval practice and are punished
Describe inhibition as an alternative explanation for forgetting
- allows an unwanted response to be stopped, while alternative response needs to get strengthen
- suggests that forgetting targets the memory itself
What is forgetting under the functional account?
forgetting –> to control retrieval in the face of competitors
What is the functional account of forgetting?
- forgetting may serve a functional purpose and therefore can also be an active process
- facilitates future retrieval attempts of practiced/strengthened memories by inhibiting competitors
How might forgetting promote flexibility and generalisation?
- forgetting allows individuals to exhibit flexible behaviour and generalise past events to new experiences
- therefore, forgetting is not necessarily failure of memory but may represent an investment in a more optimal mnemonic strategy
