Incidental forgetting
occurs without the intention to forget
motivated forgetting
purposefully diminish access to memory (e.g., unwanted memories)
superior autobiographical memory
- uncontrollable remembering
- feels as though the person relives the events they remember
- not under conscious control
- cannot forget unpleasant memories
- memories can be distracting
forgetting rate
forgetting increases as time progresses BUT the rate of forgetting is different
Ebbinhaus ‘forgetting curve’
- logarithmic relationship
- forgetting rapid initially
- less additional forgetting at longer intervals
Forgetting public events: Meeter et al., 2005
aim:
- forgetting rate of public events
task:
- 14k participants completed online study of recall and recognition for 40 events
results:
- similar to Ebbinghaus forgetting curve
forgetting personal events: Bahrick et al., 1975
aim:
- to explore forgetting rate of personal events/information
task:
- 400 US high school students were tested on recalling and recognising names of classmates after delays of up to 30 years
results:
- recognition of faces/names remained intact
- match up with faces also unimpaired
- recall a name when given a face extensively impaired
- similar to Ebbinghaus
forgetting knowledge: Barrack, 1984
aim:
- explored forgetting of foreign language taught at university
task:
- tested graduates attending annual alumni reunion
results:
- forgetting levels out after a period of 2 years
- little forgetting after this period
availability vs accessibility (memory)
recall worse after delays than recognition
availability:
- is the item in the memory store (may not have a memory trace any more)
accessibility:
- is the item accessible for retrieval
both may denote forgetting
factors that discourage forgetting
-better learning at the beginning
- repeated attempts to retrieve - (testing effect/generation effect) builds up resistance to forgetting
- Linton (1975): recalling an event reduces rate of forgetting
incomplete or inaccurate retrieval may lead to memort distortions
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
consolidation
the process that transforms new memories from a fragile state, in which they can be disrupted, to a more permanent state, in which they are resistant to disruption
synaptic consolidation
- structural changes in the synaptic connections between neurons
- may take hours - days to complete
- memories are vulnerable until these changes are complete
systems consolidation
- gradual shift of memory from hippocampus to the cortex
- memory components (in the cortex) are replayed until they are linked
- may take months - years to complete
- memories are vulnerable for as long as they rely on the hippocampus
causes of incidental forgetting
- trace decay - memories weaken due to passage of time
- context shifts - different cues are available now than the only ones at encoding
- interference - similar memories hinder retrieval
trace decay
- priming and familiarity especially prone to memory
- a memorys activations fade but memory is intact OR memory degrades as well
bio basis
- synaptic connections degrade, neurons die
- neurogenesis leads to remodeling of connections - bad for older memories, good for learning
cannot control REHEARSAL and INTERFERENCE FROM NEW EXPERIENCE when attributing forgetting to decay
contextual fluctuation
- similarity between encoding and retrieval context may explain forgetting
- incidental context differs more between retrieval and encoding over time
- incidental context is less similar to the remote past than more recent past
interference
- similar traces/ memories impede retrieval
- it is difficult to discriminate between them
- 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?
competition assumption:
memories associated to a shared cue automatically impede retrieval when the cue is presented
interference occurs due to the negative effect of having competitors
retroactive interference
a similar memory interferes with a target memory further in the past
Introducing a new (second) memory impairs recall of a first memory (especially similar)
proactive interference
a similar memory interferes with a target memory closer to the present
The tendency of older memories to interfere with retrieval of recent experiences and knowledge
more severe for recall than recognition
retroactive interference: realistic memories
Baddely and Hitch, 1977
task:
- rugby players asked to recall the names of teams they played earlier in the season
control:
- some players missed certain games, allowing discrimination of forgetting fue to time vs interference
results:
- time not a good predictor of forgetting
- forgetting increased with number of intervening games
part-set cuing impairment
- the tendency for recall to be impaired by the provision of retrieval cues drawn from the same category of items in memory
- providing hints may impede memory retrieval
- the impairments are more severe with increasing numbers of cues provided from the same set
competition
Retrieval-induced forgetting (RIF)
Anderson et al., 1994
- selective/partial retrieval can harm recall of other memories related to the retrieved item
- compared to baseline items for which no related items had been retrieved
- selective retrieval may contribute to more severe forgetting for information that is not practiced/retrieved
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
e.g., tip of the tongue, RI, Part set cuing
