Lecture 5 - Forgetting

Question 1

Incidental Forgetting

Answer 1

occurs without the intention to forget

(everyday lives)

Question 2

motivated forgetting

Answer 2

purposefully diminished access to memory e.g. unwanted memories

Question 3

superior autobiographical memory

Answer 3

uncontrolled remembering
- feels as though person relives events they remember
- it is automatic and not a conscious control
- cannot forget unpleasant memories
- memories can be distracting

Question 4

Forgetting rate

Answer 4

• forgetting increases as time progresses BUT the rate of forgetting is different
• Ebbinghaus studied this and found the forgetting curve

Question 5

Forgetting curve

Answer 5

describes the rate of forgetting after variable intervals
- logarithmic relationship:
forgetting initially rapid, less additional forgetting at longer intervals

Question 6

study on forgetting rate for public events

Answer 6

Meeter et al. 2005
- online study of recall and recognition tasks for 40 events
- found similar results to ebbinghaus forgetting curve: steep initial drop followed by slower forgetting rate
- recall for events dropped from 60% to 30% in a year
- recognition for same events was less affected than recall

Question 7

study on forgetting personal events/information

Answer 7

Bahrick et al.1975
- high-school graduates tested on recalling and recognizing names of classmates after delays of up to 30 years
- found that recognition of faces/names intact
- match up faces and names unimpaired
BUT
- recall when given a person’s picture impaired
- rate of forgetting similar to Ebbinghaus forgetting curve
- recall more affected than recognition

Question 8

study on forgetting knowledge

Answer 8

Bahrick 1984
- explored forgetting of foreign language taught at university
- tested graduates attending annual alumni reunion
- found that forgetting is rapid but levels out after 2 years and then there is little forgetting

Question 9

what should be considered when examining forgetting

Answer 9

availability vs accessibility
- as recall is generally worse after delays than recognition
- both accessibility and availability may denote (indicate) forgetting

Question 10

availability

Answer 10

is the item in memory store?
- item may no longer have a memory trace

Question 10

accessibility

Answer 10

is the item accessible for retrieval?
item may be stored but not accessible

Question 10

Factors that discourage forgetting

Answer 10

• better learning at the beginning makes memories more durable and less susceptible to forgetting
• repeated attempts to retrieve - (testing effect/ generation effect) builds up resistance to forgetting

Question 11

what did Linton 1975 show

Answer 11

testing on personal memories, or recalling, reduces the rate of forgetting personal memories
- more times an event is tested/recalled, reduces rate of subsequent forgetting more

Question 12

memory distortions

Answer 12

incomplete or inaccurate retrieval may lead to memory distortions

Question 13

Jost’s law for distorted memories and memory forgetting

Answer 13

• all else equal, older memories are more durable and forgotten less rapidly than newer memories
• new memories are initially more vulnerable to distortion until they are consolidated

Question 14

Consolidation

Answer 14

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

Question 15

reconsolidation

Answer 15

the process by which a consolidated memory restabilizes again after being reactivated by reminders

during reconsolidation a memory is vulnerable to disruption

Question 16

causes of incidental forgetting

Answer 16

1. trace decay
2. context shifts
3. interference

Question 17

trace decay

Answer 17

memories weaken due to passage of time
e.g. facts learned in school fade out of memories

Question 18

context shifts

Answer 18

different cues are available now than the ones available at encoding
e.g. school is a completely different context than now

Question 19

interference

Answer 19

similar memories hinder retrieval
e.g. after a biology lecture you forgot what you learned in chemistry lecture an hour before

Question 20

trace decay explanation

Answer 20

• memories weaken due to time passing
• memories activation may fade but memory itself is intact (available but not accessible)
• memory itself and its elements (associations) degrade along with activity level

Question 21

trace decay: biological basis

Answer 21

• synaptic connections degrade and neurons die as time goes by: memories die or fade in the same way
• opposite biological mechanism can also explain decay e.g. neurogenesis (growth of neurons) as structure remodeled and connections gradually remodified … good for learning but bad for old memories as they may suffer connections due to new connection expansion

Question 22

trace decay validity: what two factors cannot be controlled when attributing forgetting to decay

Answer 22

1) rehearsal
2) interference from new experiences

Question 23

alternative factors of incidental forgetting

Answer 23

correlates of time

Question 24

correlates of time

Answer 24

forgetting may not be caused by the passage of time itself but by a correlate of time - contextual fluctuation - interference

Question 25

contextual fluctuation (similar to encoding specificity hypothesis)

Answer 25

- similarities between encoding and retrieval context may explain forgetting - incidental context differs more between retrieval and encoding over time - over time context changes - contextual fluctuation much higher over longer periods of time - so we don't have appropriate cues to access memories

Question 26

interference

Answer 26

- similar traces/memories impede retrieval - difficult to discriminate between them - similar memories accumulate over time, making it more difficult to discriminate - cues that can be used to access memory may also become associated with others

Question 27

how does interference occur: competition assumption

Answer 27

due to competition of memories; memories associated to a shared cue automatically impede retrieval when the cue is presented - as cue activates all associates - activated associates compete for access to consciousness - competitors hinder access to target memory

Question 28

when does interference increase

Answer 28

increases with the number of competitors a target memory has

Question 29

2 interference phenomena

Answer 29

- retroactive interference - proactive interference

Question 30

retroactive interference

Answer 30

target memory happened before similar memories

Question 31

proactive interference

Answer 31

target memory happened after similar memory that causes interference

Question 32

retroactive interference

Answer 32

- introducing a second /new memory impairs recall of a first memory (especially similar) - strong interference if the two memories share same cue - more recent memory training results in more impairment of first/older memory

Question 33

Baddeley and Hitch 1977 retroactive interference on realistic memories

Answer 33

- rugby players asked to recall the names of teams they played earlier in the season - some players missed certain games, allowing discrimination of forgetting due to decay vs interference - time was not a good predictor of forgetting BUT - forgetting increased with number of intervening games (similar experiences) - forgetting due to interference rather than decay as new rugby games interfered with previous ones making them less accessible

Question 34

proactive interference

Answer 34

- tendency of older memories to interfere with retrieval of recent experiences and knowledge - more previous learning experiences increases rate of forgetting new ones - PI more severe for recall than recognition

Question 35

other causes of forgetting

Answer 35

- part-set cuing impairment - retrieval-induced forgetting

Question 36

part-set cuing impairment

Answer 36

- recall impaired by provided cues (hints)(of competing items) - impairment more severe with increasing number of cues - due to the associations with similar cues being strengthened and competition for non-cues increases

Question 37

retrieval-induced forgetting

Answer 37

- Anderson et al. - if one item is retrieved more than others, it impairs recall of other items related to retrieved item (both on the same list) - selective retrieval contributes to practice/testing effect and more forgetting for things not retrieved

Question 38

RIF implications and conclusions

Answer 38

- retrieval (testing effect) can be beneficial for strengthening memories BUT - selective strengthening or incomplete retrieval may diminish benefits as it causes forgetting of related things

Question 39

interference mechanisms (why do we forget) - associative blocking hypothesis

Answer 39

a cue fails to elicit a target trace because it repeatedly elicits a stronger competitor, leading people to abandon efforts to retrieve target

Question 40

what does associative-blocking hypothesis explain

Answer 40

tip-of-the-tongue (incorrect responses) part-set cuing Retrospective interference cue overload

Question 41

interference mechanisms - associative unlearning

Answer 41

associative bond linking a stimulus to a memory trace is punished by weakening it after being retrieved in error cant demonstrate empirically - explains RIF and RI; competitors intrude at retrieval practice are punished

Question 42

function account of forgetting - the benefits

Answer 42

- we forget in order to diminish competition in retrieval - functional purpose, we forget things we no longer need (active process)

Question 43

flexibility and generalization of memory - why forgetting is beneficial

Answer 43

- goals of memory is for good decision-making - forgetting allows individuals to have flexible behaviour - can generalize past events to new experiences - not a failure of memory, but investment in more optimal mnemonic strategies - forgetting can increase cognitive efficiency - Richards and Frankland

Question 44

What term did Anderson et al. (1994) coin to refer to the predisposition for selective retrieval of some exemplars from long-term memory to impair later recall of related items?

Answer 44

Retrieval induced forgetting