Consolidation & Forgetting

Question 1

Consolidation definition

Answer 1

Integrating new information with old information

Question 2

Forgetting definition

Answer 2

Information loss

Question 3

When we forget something, is the information lost?

Answer 3

1. Info may be lost - memory trace itself is poor/deteriorating - PASSIVE forgetting - problem with storage
2. Info may be inaccessible - lack of retrieval cues / interference - problem with retrieval - PASSIVE forgetting
3. Info may be inhibited - ACTIVE forgetting

Forgetting is adaptive

Question 4

Brain damage resulting in inability to form new memories

Answer 4

Damage to the hippocampus and other MTL structures

e.g. case study of HM

Question 5

What is the hippocampus critical for?

Answer 5

Critical for the acquisition of declarative memories (opposite to procedural) e.g. episodic (first day of school) or semantic (general knowledge facts; capital of France)

Amnesics - can’t form new memories
Normal controls - when activation in MTL structures on brain scan - that can predict whether info will be later recalled

Question 6

For long term memory; consolidation process

Answer 6

Hippocampus –> neocortex

Question 7

First step of consolidation

Answer 7

Hippocampus binds information together to form a higher level representation

Question 8

Second step of consolidation

Answer 8

This is stored and distributed across networks in other cortical areas and INTEGRATES with old information

Question 9

What is knowledge?

Answer 9

Structured/organised information

Question 10

What is the Complementary Learning Systems model?

Answer 10

Memories are first stored via synaptic changes in the hippocampal system - these changes support reinstatement of recent memories in the neocortex

Neocortical synapses change a little on each reinstatement, and that remote memory is based on accumulated neocortical changes. Models that learn via changes to connections help explain this organization.

These models discover the structure in ensembles of items if learning of each item is gradual and interleaved with learning about other items.

This suggests that the neocortex learns SLOWLY to discover the structure in ensembles of experiences.

The hippocampal system permits RAPID learning of new items without disrupting this structure, and reinstatement of new memories interleaves them with others to integrate them into structured neocortical memory systems.

Question 11

Damage to the hippocampus

Answer 11

Damage to the hippocampal system disrupts recent memory but leaves remote memory intact

Question 12

Catastrophic interference

Answer 12

New information can interfere and replace old information

Question 13

First step to complementary systems model

Answer 13

Fast, initial episodic learning mediated by the hippocampus (vulnerable memories)

Question 14

Second step to complementary systems model

Answer 14

Slow, long-term storage in NEOCORTEX involving integration with existing knowledge (integration reduces interference)
Less vulnerable memories, as they are being embedded

Question 15

Explanation of consolidation process

Answer 15

Slow neocortical learning process that “stabilises” or “fixes” memories in LTM across hours/days

Question 16

Retrograde amnesia

Answer 16

Retrograde amnesia is a form of amnesia where someone is unable to recall events that occurred before the development of the amnesia, even though they may be able to encode and memorise new things that occur after the onset - can’t recall recently formed memories as well due to disrupted consolidation process

Retrograde amnesia usually follows damage to areas of the brain other than the hippocampus (the part of the brain involved in encoding new memories), because already existing long-term memories are stored in the neurons and synapses of various different brain regions

Question 17

Why does consolidation happen in sleep?

Answer 17

Memories are transferred/laid down in neocortex in sleep due to minimal external input at that time

Question 18

Sleep and learning

Answer 18

Particularly for procedural (non-declarative)

also affects declarative (episodic and semantic)

Question 19

Early sleep - important for?

Answer 19

Early sleep is slow wave sleep

Important for consolidation of HIPPOCAMPUS-dependent declarative learning

Question 20

Late/REM sleep - important for?

Answer 20

Procedural learning

Question 21

Walker et al (2002) findings

Answer 21

Procedural learning - compare performance after x amount of hours being asleep and x hours being awake = - Overnight improvement

• Further improvement over subsequent nights
• Sleep deprivation reduces improvement

Declarative memory
Sleep may “PROTECT” memories from interference
% recall is a lot higher after sleep as opposed to awake condition - study two sets of word pairs (Paired-associate learning)

Question 22

Clay et al (2007)

Answer 22

Learning of new words tested by assessing the presence of semantic interference with new words

Slower naming with related distractors but only after 1 week

Question 23

Dumay & Gaskell (2007)

Answer 23

Learning of new words

AM group: study 8am - test 8pm - test 8am
PM group: study 8pm - test 8am - test 8pm
After sleep = better declarative memory

Question 24

Forgetting curves (Ebbinghaus)

Answer 24

Ebbinghaus examined own ability to learn lists of nonsense syllables - found that forgetting function may be LOGARITHMIC
Forgetting is generally faster shortly after learning and then slower decline
graph = retention (%) vs elapsed time (days)

Question 25

Savings method

Answer 25

Reduction in number of trials necessary to relearn materials over different retention intervals

Question 26

Bahrick (1984) - logarithmic forgetting curves

Answer 26

``` Consistent with Ebbinghaus Retention of Spanish vocab over 50 years Rapid loss in first 3 years Relatively stable until 35 years 35-50 years further decline ``` Tested % Spanish original vocab retained

Question 27

Permastore

Answer 27

Memories that appear to be very resistant to loss

Question 28

Meeter, Murre & Janssen (2005) - logarithmic forgetting curves

Answer 28

14000+ ppts answered questions about publicised world events Consistent with Ebbinghaus Rapid loss at short intervals then slower loss Forgetting rates DON'T depend on degree of learning

Question 29

Remembering can cause forgetting (RIF)

Answer 29

Retrieval can modify memories, recalling some information changes the record of what you remember

Question 30

Adaptive mechanism of remembering

Answer 30

Repeated retrieval strengthens a memory trace | Makes related, un-retrieved information less accessible

Question 31

Retrieval-induced forgetting (Anderson et al, 1994)

Answer 31

To allow successful retrieval, we use inhibition to resolve competition or interference arising during retrieval - we facilitate remembering by facilitating forgetting

Question 32

Initial RIF study by Anderson

Answer 32

Paired-associate learning - word pairs e.g. fruit-lemon, fruit-banana, metal-silver Learning task e.g. retrieval practice with fruit-le___ Final test e.g. fruit-L, fruit-B, metal-S Fruit-L = practiced relevant word (Rp+) - good recall due to benefits of practice Fruit-B - unpracticed relevant word (Rp-) - poor recall due to inhibited to prevent interference (forgetting is cue-dependent) Metal-S - unpracticed irrelevant word (NRP) - baseline control pair

Question 33

Why are some items inhibited?

Answer 33

Similar related words to practice words - inhibited because they compete during retrieval

Question 34

Another Anderson et al (1994) study - items of low and high taxonomic strength

Answer 34

Study with items of high and low taxonomic strength fruit-orange = high strength fruit-kiwi = low strength Low taxonomic strength items compete loss, these items suffer less from RIF

Question 35

Storm et al (2007)

Answer 35

Directed forgetting Participants studied a list then received instruction to forget this list and study a new list "Forgotten" items should not compete and indeed don't suffer from RIF

Question 36

Remembering and forgetting facts study | Practiced topic vs. related topic vs. baseline unrelated topics

Answer 36

Practiced topic: actor "is playing" either guitar // oboe Guitar was the practiced item Oboe was the shared topic Related topic: teacher "is playing" saxophone // drum - shared relation items Baseline topic with completely different sentence structure Practiced item recall 60% Shared topic recall 29% Shared relation item recall 31% Baseline topic 27% Low integrators showed stronger impairment than high integrators

Question 37

Integration reduces RIF

Answer 37

Integrated bits of information are less likely to interfere and compete with one another Study cue-target pairs: standard instructions vs. integrative instructions Integrative instructions are less vulnerable . to RIF In complex structures or networks; concepts are connected by associative links - network functions as a "unit" - presence of links = ACTIVATION not competition

Question 38

In complex structures or networks; concepts are connected by associative links

Answer 38

Networks function as a unit | Presence of links = activation, not competition

Question 39

Scaling up to stories and RIF e.g. eyewitness

Answer 39

Remembering and forgetting in eyewitness testimony - High motivation to remember - High likelihood of telling same story over and over

Question 40

Experiment 1 (RIF and stories)

Answer 40

Participants take policeman's perspective; study pictures of objects stolen from 2 houses

Question 41

Experiment 2 (RIF and stories)

Answer 41

Participants study series of slides showing 2 events (2 women making bogus charity collections) . clear RIF

Question 42

Time-course effects (Temporary effects)

Answer 42

Inhibits info irrelevant for current task Weaker effects with delayed retrieval practice

Question 43

Education - classroom learning - experts

Answer 43

Due to paradox of expertise, experts have more knowledge - retrieval should result in more inhibition (more knowledge to inhibit) - but it doesn't as INTEGRATION of knowledge PROTECTS against forgetting

Question 44

Comparing experts vs novices on symptoms of schizophrenia and autism (Anderson & Bell, 2001)

Answer 44

Test immediately or 1 day later | Results: novices = more inhibition (higher RIF effect)

Question 45

Downside of RIF

Answer 45

Simplification

Question 46

Can we suppress memories?

Answer 46

Freudian repression We do have some control over unwanted memories (Anderson & Green, 2001)

Question 47

Link to amount of RIF and depression - studies show if there is deficit to one's RIF --> can't suppress negative memories least RIF - clinically more depressed than individuals exhibiting the most retrieval-induced forgetting

Answer 47

``` If a deficit in one's susceptibility to retrieval-induced forgetting can lead to negativity biases in autobiographical memory, and to an increased propensity for experi- encing anxiety and intrusive memories, then perhaps such a deficit stands as a significant risk factor for depression. In support of this hypothesis, correlations between retrieval-induced forgetting and depression have been observed. Groome and Sterkaj (2010), for example, found that 21 individuals diagnosed with clinical depression exhibited significantly less retrieval-induced forgetting than 21 control participants who were not clinically depressed. Similarly, in the study by Storm and Jobe (2012b), when data from participants suffering at least mild levels of depression were analyzed (i.e., scores of 14 or higher on the BDI-II; Beck et al., 1996), a significant correlation was observed such that individuals exhibiting the least retrieval-induced forgetting were significantly more depressed (as measured by severity on the BDI-II) than were individuals exhibiting the most retrieval-induced forgetting ```

Question 48

Executive Deficit Hypothesis

Answer 48

People differ in the ability to suppress unwanted memories because they differ in executive control abilities

Question 49

Most inhibition seen in people with

Answer 49

``` High working memory capacity High inhibition Highly traumatic experiences Younger (vs older) adults Older children ```

Question 50

RIF studies

Answer 50

``` Memory phenomenon where remembering causes forgetting of other information - context of retrieval inhibition 3-phase experiment 1. study 2. practice of some studied material 3. final test of all studied material ``` studied/practiced words = Rp+ words related to practice words = Rp- unrelated words = Nrp

Question 51

Who does this phenomenon occur?

Answer 51

Process actively inhibiting information OR Interference from other information in memory

Question 52

Which words suffer as a result of prior retrieval?

Answer 52

Rp- (words related to but unstudied) | poorly recalled in comparison to unrelated words

Question 53

Calculating RIF effect

Answer 53

Rp+ 81% Rp- 55% NRp 68% NRp - Rp- = 68 - 55 = 13% RIF effect take away related word recall from unrelated words

Question 54

Boundary conditions of RIF

Answer 54

SEMANTIC INTEGRATION - Influence of integration of learned material - strength of the semantic relationship between competing targets - Duration of RIF effect - long retention interval - Effect of type of test format most susceptible to RIF - retrieval-cue test (paired associative learning) vs. free recall tests (inconsistent results) - Mood state and stress levels - some studies show RIF is only seen in cue-dependent tests NOT cue-independent

Question 55

Retrieval-induced forgetting summary

Answer 55

Memory is modified through the act of retrieval. Although retrieving a target piece of information may strengthen the retrieved information itself, it may also serve to weaken retention of related information. This phenomenon, termed retrieval-induced forgetting, has garnered substantial interest for its implications

Question 56

Anderson et al (1994) study

Answer 56

?

Question 57

Stickgold/Diekelman | Stickgold & Walker x 2

Answer 57

Sleep/consolidation studies

Question 58

Storm et al

Answer 58

RIF - learning/eyewitness/social cognition

Question 59

Anderson & Green

Answer 59

Suppressing unwanted memories by executive control (executive deficit hypothesis)