Memory (AQA A-Level Psychology) (NEW!!!)

How are STM and LTM distinguished?

STM and LTM are often distinguished in terms of their coding, capacity and duration.

STM and LTM are often distinguished in terms of their coding, what does this refer to?

Coding refers to the format in which information is stored in the various memory stores.

- Information enters the brain via the senses (e.g. eyes and ears) and then is changed to another form so that it can be stored in memory. It can be stored in the form of sounds (acoustic), images (visual) or meaning (semantic)

STM and LTM are often distinguished in terms of their capacity, what does this refer to?

Capacity refers to the amount of information that can be held in a memory.

STM and LTM are often distinguished in terms of their duration, what does this refer to?

Duration refers to the length of time that information can be held in memory

What is the Sensory Register? (Sensory Store)

- how it works

- environmental stimuli ( the sound of someone talking) enter the sensory register, comprising five separate stores for each sense

- the primary stores are iconic (for visual information, initially encoded visually) and echoic (for sound-based information, initially encoded acoustically).

sensory store coding

depending on the sense that is picked up - e.g. visual, auditory or tactile. (modality specific)

sensory store duration

less than half a second

sensory store capacity

huge capacity (millions or receptors)

What is Short-term memory (STM)?

Short term memory is your memory for immediate events. It temporarily stores information received from the sensory register.

How is information transferred from the sensory register to Short term memory?

attention

What happens if information is not attended to when it enters the sensory register?

leads to spontaneous decay

STM coding

acoustically (Baddely 1966)

STM capacity

between 5 and 9 items (Miller 1946)

STM duration

18-30 seconds unless it is rehearsed (Peterson and Peterson 1959)

How is information transferred from STM to LTM?

prolonged rehearsal e.g verbally repeating a telephone number

How is information transferred from LTM to STM?

retrieval

What is Long-term memory (LTM)?

memory for events that have happened in the more distant past

LTM coding

semantically (Baddeley 1966)

LTM capacity

potentially unlimited

LTM duration

lifetime (Bahrick 1975)

Baddely (1966) on coding in STM and LTM

- procedure

LABORATORY EXPERIMENT

- participants were given four sets of words to learn

- acoustically similar words (cat, cap, can) or dissimilar (pit, few, cow)

- semantically similar (great, large, big) or dissimilar (good, huge, hot).

- they were required to recall the words in the original order either immediately (testing STM) or after a 20-minute delay (testing LTM)

Baddely (1966) on coding in STM and LTM

- findings

- immediate recall worse with acoustically similar words -> indicates acoustic coding in short-term memory (STM)

- recall after 20 minutes worse with semantically similar words -> suggests semantic encoding in long-term memory (LTM)

Why was immediate recall worse with acoustically similar words?

STM causing acoustic confusion and becoming distracted by sounds of words thus not recalling in order

Why was prolonged recall worse with semantically similar words?

LTM causing semantic confusion and becoming distracted by meaning of words thus not recalling in order

What is a strength of Baddeley's 1966 study on coding in STM and LTM?

✓ Showed differences between stores

• showed differences between stores.

• Later research showed that there are some exceptions to Baddeley's findings, e.g. types of coding.

• However, the idea that STM uses mostly acoustic coding and LTM mostly semantic has stood the test of time.

• This was an important step our understanding of the memory system, which led to the creation of the MSM.

What is a strength of Baddeley's 1966 study on coding in STM and LTM?

✓ there is a high degree of control over extraneous variables

• A strength of Baddeley's study is that there is a high degree of control over extraneous variables.

• This allows us to see clearly that the IV (coding: semantic or acoustic) was what affected the DV (recall), improving the validity of results

- This also means the experiment can be easily replicated

What is a limitation of Baddely's 1966 study on coding in STM and LTM?

✘ it didn't use meaningful material.

• A limitation of Baddeley's study is that it didn't use meaningful material.

• The words used in the study were artificial had no personal meaning to participants. When processing more meaningful information, people may use semantic coding even for STM.

• This means that the results of this study have limited application in the real-world. We should be cautious about generalising the findings to different kinds of memory task.

Baddeley et al. (1975) procedure

LAB EXPERIMENT using a dual task paradigm.

- participants engaged in separate visuo-spatial sketch pad tasks - tracking a moving point of light and mentally navigating a capital 'F.'

Baddeley et al. (1975) results

• Participants found it harder to complete two visual tasks at the same time than to complete the visual and verbal task.

• The greater difficulty is because both visual tasks compete for the same limited resources, but when doing a verbal and visual task simultaneously, there is no competition.

Jacobs (1887) on capacity of STM

- procedure

LAB EXPERIMENT

• Used a digit span - researcher read four digits and increased until the participant could not recall the order correctly immediately.

Jacobs (1887) on capacity of STM

- findings

• Digits = 9.3

• Letters = 7.3

What is a strength of Jacobson's (1887) study on capacity of STM?

✓ Replication of Jacob's study

• Older studies often lacked adequate controls, e.g. , some participants' digit spans might have been underestimated because they were distracted during testing (confounding variable).

• However, Jacob's findings have been confirmed and validated by other, better controlled studies since.

• This suggests that Jacob's study has 'stood the test of time' and is a valid test of digit span in STM.

Miller (1946) on capacity of STM

- procedure

• made observations and noted that the span of immediate memory is about 7 items.

• For example, he noted that people can count 7 dots flashed on a screen but not many more. The same is true if you ask people to recall musical notes, words or even letters.

Miller (1946) on capacity of STM

- findings

- STM span is approximately 7 items (plus or minus 2).

recall improves with chunking - organizing data into meaningful groups.

Example: Transforming BBCCAITVAARAC into BBC, CA, ITV, AA, RAC, which occupies only 5 memory slots.

What is a strength of Miller's 1946 study on capacity of STM?

✓ it has many practical applications.

• A strength of research into the capacity of STM is that it has many practical applications.

• Research into chunking laid the foundations for the postcode system we use in the UK today.

• Baddeley discovered that if the initial letters of a postcode made up something meaningful (e.g. BS for Bristol) it made it easier to remember.

• This shows how research into the capacity of STM has helped improve the efficiency of memory in a real life situation.

Peterson and Peterson (1959) on duration of STM

- procedure

LABORATORY EXPERIMENT

• Sample of 24 undergrad students.

• Peterson and Peterson gave participants 'nonsense trigrams' (for example CKX), which they had to recall after a retention interval of varying amounts of time from 0-18 seconds.

• On presentation of each trigram, they were required to verbally count backwards in threes from a specified number to prevent participants rehearsal

Peterson and Peterson (1959) on duration of STM

- findings & conclusion

• After 3 seconds, 80% recalled correctly.

• After 18 seconds, fewer than 10% of trigrams were recalled.

Peterson and Peterson (1959) on duration of STM

- conclusion

• Rehearsal got progressively worse as the delay grew longer.

• This suggests that the duration of STM is approximately 18 (to 30) seconds if rehearsal is prevented.

What is a limitation of Peterson and Peterson's 1959 study on duration of STM?

✘ Use of artificial stimulus

• A limitation of Peterson and Peterson's study is the artificial stimulus.

• Recalling trigrams does not reflect most everyday memory activities where what we are trying to remember is meaningful.

• On the other hand, we do sometimes try to remember fairly meaningless things, such as phone numbers, so the study is not totally irrelevant.

• This means the study lacked ecological validity as it may not be possible to generalise findings to real-life.

Bahrick et al (1975) on duration of LTM

- procedure

FIELD EXPERIMENT to explore memory retention, graduates aged 17 to 74 from an American high school.

Tasks:

Photo recognition: participants selected former classmates from 50 graduation photos

Free recall: Participants named classmates without visual aids.

Bahrick et al (1975) on duration of LTM

- findings

(1) Photo recognition task:

- 90% accuracy if graduated within 15 years

- 70% accuracy if graduated within 48 years

(2) Free recall task:

- 60% accuracy if graduated within 15 years

- 30% accuracy if graduated within 48 years

Bahrick et al (1975) on duration of LTM

- conclusion

LTM can potentially last for years, if not a life time (shown particularly in photo recognition task)

What is a strength of Bahrick et al's 1975 study on duration of LTM?

✓ field experiment, higher external validity

• One strength of Bahrick's study is that it is a field experiment so is higher in external (ecological) validity than other memory studies.

• Also, real life memories were studied (i.e. people's names and faces), thus the behaviour shown is more valid and authentic than other research which conducted with meaningless pictures or words in laboratory experiments, where recall rates were lower.

• This suggests that Bahrick et al's study reflects a more 'real' estimate of the duration of LTM (high external validity).

What is a limitation of Bahrick et al's 1975 study on duration of LTM?

✘ no control over confounding variables

• A downside of real life research (field experiments) is that confounding variables are not controlled, thus making it harder to conclude that the DV was only affected by the IV.

• Participants may have spent further time with certain classmates / stayed in touch.

• This would make recollection a lot easier as time frame since a last interaction would be reduced, reducing the validity of results gathered.

What is the multi-store model of memory?

- Atkinson and Shiffrin (1968)

linear model illustrating the information flow through three memory stores (sensory store -> STM -> LTM)

What is a strength of the Multi-store model of memory?

✓ Research support from Baddeley

• P: Research support for the idea of LTM and STM being different and separate stores provided by Baddeley (1966)

• E: In his study on coding, he gave participants one of four lists of words to remember and found that acoustically similar words were harder to recall immediately and semantically similar words were harder to recall after 20 minutes.

• E: It was concluded that acoustic confusion was occurring in STM, and semantic confusion in LTM, suggesting STM codes acoustically and LTM semantically

• L: This shows that the two types of memory are different from one another, as MSM suggests.

What is a limitation of the Multi-store model of memory?

✘ research studies supporting the MSM use artificial materials

P: A limitation, despite such apparent support, is that the research studies supporting the MSM use artificial materials.

• E/E: In everyday life, we form memories related to all sorts of useful things(people's faces, names etc). However, many of the supporting studies for MSM didn't use these realistic materials, but rather digits, letters and sometimes words which hold no meaning.

• L: This suggests that the MSM lacks external validity. Research findings may reflect how memory works with meaningless material in a lab setting, but MSM may not be an accurate/valid model of how memory works in our everyday lives, where we have to remember much more meaningful information.

What is a limitation of the Multi-store model of memory?

✘ evidence from Shallice and Warrington's 1970 study, suggesting that there is more than one type of STM

P: A limitation of the Multi-store model (MSM) is its assertion that Short-Term Memory (STM) is a singular store, contrary to evidence indicating multiple types of STM.

E: Shallice and Warrington's (1970) study of KF, an amnesic patient, revealed poor STM for verbally presented digits but improved recall when digits were self-read visually.

A: This is a weakness because it suggests distinct STM stores for visual and verbal information.

L: The finding challenges the MSM's unitary STM concept, highlighting the need for a model like the Working Memory Model, which incorporates separate stores like the phonological loop and visuo-spatial sketchpad.

What is a limitation of the Multi-store model of memory?

✘ the MSM only explains one type of rehearsal

P: One limitation of the Multi-store model (MSM) is that it exclusively focuses on one rehearsal type.

E: Craik and Watkins argued that the critical factor for memory retention is the type of rehearsal, not the quantity. They identified 2 types of rehearsal

Maintenance rehearsal (verbal repetition): Keeps information in Short-Term Memory (STM).

Elaborative rehearsal: Essential for long-term storage, involving linking information to existing knowledge or considering its meaning.

A: This is a weakness because it highlights that the MSM fails to incorporate research findings emphasizing the pivotal role of rehearsal type in memory mechanisms.

L: As a result, this lower the explanatory power of the MSM.

Craik and Watkins

The critical factor for memory retention is the type of rehearsal, not the quantity.

Two types of rehearsal:

Maintenance rehearsal (verbal repetition): Keeps information in Short-Term Memory (STM).

Elaborative rehearsal: Essential for long-term storage, involving linking information to existing knowledge or considering its meaning.

Tulving (1986) and types of long-term memory?

Multi-store model criticized for treating LTM as a single vast store with no distinctions.

Tulving (1986) proposes multiple types of LTM, each linked to different functions and associated with different brain areas.

categories: episodic, semantic, procedural.

What is episodic memory?

- LTM for memories of life events

e.g storing events such as birthdays and recent dentist visits.

declarative -> can be expressed verbally, involving 'knowing that' something is true

available for conscious inspection -> requires conscious thought and effort to consciously inspect

time stamped -> stored with reference to time, place, people, objects, and associated emotions.

What is semantic memory?

LTM for factual and general knowledge about the world.

e.g capital cities and the meaning of words and concepts

declarative -> can be expressed verbally, involving 'knowing that' something is true.

available for conscious inspection -> recalling semantic memories is deliberate and requires conscious thought

not time stamped -> knowledge is recalled without remembering when or where it was learned

What is procedural memory?

LTM for motor skills and learned actions.

e.g tying a shoe-lace or playing the piano.

non-declarative knowledge -> cannot necessarily be expressed verbally, focused on 'knowing how' to do things.

not open for conscious inspection -> typically recalled without conscious effort.

not time stamped -> knowledge is recalled without remembering when or where it was learned

- acquired through repetition and practice, becoming automatic skills and habits.

Tulving's 1989 study on the differences in processing of episodic and semantic memories:

- procedure

aim - examine brain activity during semantic and episodic memory retrieval

- six volunteers received radioactive gold injection (scanned using a gamma ray detector to detect its location.)

- pps thought about 4 semantic topics - involving general knowledge and 4 episodic topics (involving personally experienced events)

- involved pps thinking about a topic, gold injection after 60 seconds, and scanning 8 seconds later

Tulving's 1989 study on the differences in processing of episodic and semantic memories:

- results/findings

semantic memories -> left prefrontal cortex

episodic memories -> right prefrontal cortex

Tulving's 1989 study on the differences in processing of episodic and semantic memories:

- conclusions (2)

• episodic and semantic LTMs appear to involve different brain areas and thus are separate forms of LTM

• The fact that episodic and semantic LTMs involve different brain areas suggests a biological basis to differences in LTM

What is a strength of Tulving (1986) and the 3 types of long-term memory?

✓ episodic memory is supported by case study evidence

P: A strength of episodic memory is that it is supported by case study evidence, such as the clinical cases study of HM.

E: HM had brain surgery at 27 to alleviate epilepsy, resulting in hippocampus removal and severe amnesia

- demonstrated intact procedural memory by learning and retaining mirror drawing skills despite no conscious recollection of the task

- episodic memory impaired as he could not recall events that had happened to him

A: This is a strength because it highlights a dissociation between intact procedural memory and impaired episodic memory, showing that there are different long-term memory stores, not only different in functionality but also location within the brain.

L: As a result, this increases the explanatory power of Tulving's theory.

What is a strength of Tulving (1986) and the 3 types of long-term memory?

✓ real world applications

P: one strength of Tulving's research is that it has practical applications for psychologists.

E: For example, research demonstrates the potential improvement of episodic memories in older individuals with mild cognitive impairment.

Comparison of a trained group with episodic memory training to a control group without training showed a significant performance boost in the trained group.

L: Highlights the advantage of distinguishing between LTM types for the development of specific and effective memory-enhancing treatments.

patient HM

- HM had brain surgery at 27 to alleviate epilepsy, resulting in hippocampus removal and severe amnesia

- demonstrated intact procedural memory by learning and retaining mirror drawing skills despite no conscious recollection of the task

- episodic memory impaired as he could not recall events that had happened to him

Highlighted a dissociation between intact procedural memory and impaired episodic memory.

What is a limitation of Tulving (1986) and the 3 types of long-term memory?

✘ there are problems with clinical evidence

P: A limitation is that there are problems with clinical evidence

E: Evidence is often based on clinical cases e.g. HM about what happens when memory is damaged.

• However, there is a serious lack of control of different variables in these studies (e.g. cannot control the precise location of damage or personality variables). For all we know, HM's (episodic) memory might have been bad before his injury, which confounds the results of these clinical studies.

L: Therefore, it is difficult to generalise from these case studies to determine the exact nature of LTM.

What is the working model of memory? (WMM)

Baddeley and Hitch Proposal (1974)

- divides STM into a central executive oversees 3 slave systems

• proposes that STM was more complex than just being a temporary store

- they saw STM as active processor, holding several pieces of information simultaneously while they are being 'worked on', for example when working on an arithmetic problem or comprehending language.

Working Memory Model components

Central Executive

↕️

Visuo-spatial sketchpad

Episodic buffer

Phonological loop

↕️

Long term memory

What is the Central Executive?

- coordinates the activities of the 3 slave systems.

• monitors incoming data from the senses, makes decisions as to which data should be attended to and then allocates different tasks to the relevant slave-systems.

central executive coding

modality free (codes in all sensory forms)

What is the Visuo-spatial sketchpad (VSS)?

- deals with temporary storage of visual and spatial information - capacity of 3-4 items

- essentially holds static images and manipulates them

- sub-divided into a visual cache and inner scribe

central executive capacity

very limited, cannot attend to too many things at once

visual information example

what things look like, such as the shape and size of letters in a word

spatial information

the relationship between objects

VSS capacity

3-4 items

VSS coding

relies on a visual code in terms of shape, size and colour

visual cache

stores information about visual items i.e. shape and colour

inner scribe

deals with spatial relations and records the arrangement of obiects in the visual field

What is the phonological loop?

- deals with auditory/sound information or deals with both written and spoken material

• subdivided into the phonological store (inner ear) and the articulatory process (inner voice)

• the phonological store stores the words you hear (in speech form)

• the articulatory process allows for maintenance rehearsal

• as a limited capacity / the capacity of the loop is what can be said in 2 seconds

phonological store

holds words that have recently been heard, like an 'inner ear'

phonological store duration

2 seconds

articulatory process

allows maintenance rehearsal

- words or sounds are silently repeated in a 'loop' to keep them in working memory while they are needed, such as when trying to remember a telephone number by sub-vocally repeating it over and over, like an 'inner voice'.

articulatory process capacity

2 seconds worth of what you can say before the trace fades away

phonological loop coding

acoustic

What is the episodic buffer?

• provides a general storage facility, which combines information from the other stores (visual, spatial and verbal) rather than separate strands and also from long term memory

• it temporarily stores this information and then integrates it in order to construct a mental episode of what is being experienced right now

episodic buffer capacity

limited, about 4 chunks

episodic buffer coding

modality free

What is a strength of the working memory model? (WMM)

✓ Clinical evidence from patients with brain damage supports the existence, of a separate visual and acoustic store.

P: A strength of the WMM is that Clinical evidence from patients with brain damage supports the existence, of a separate visual and acoustic store.

E: Shallice and Warrington's (1970) study of KF, an amnesic patient who had suffered a motorcycle accident, revealed poor STM for verbally presented digits but improved recall when digits were self-read visually.

A: KF uses different slave systems to recall verbal words, the phonological loop and visual words, the Visuo-spatial sketchpad. Damage to the phonological loop may explain worse performance with verbal words.

L: This supports the working memory model as results suggest that different structures in the brain control the ability of different slave systems.

What is a strength of the working memory model? (WMM)

✓ studies of dual task performance support the separate existence of the visuo-spatial sketchpad

- Baddeley et al. (1975)

P: Another strength is that studies of dual task performance support the separate existence of the visuo-spatial sketchpad.

E: Baddeley et al (1975) performed a lab experiment with a dual task paradigm to prove the existence of the VSS.

Participants engaged in separate visuo-spatial sketch pad tasks - tracking a moving point of light and mentally navigating a capital 'F.'

• Participants found it harder to complete two visual tasks at the same time than to complete the visual and verbal task.

A: The greater difficulty is because both visual tasks compete for the same limited resources, but when doing a verbal and visual task simultaneously, there is no competition.

L: Therefore, dual task performance provides evidence for the separate existence of different STMs for different information - PL for acoustic, VSS for visual. The MSM cannot explain this.

What is a strength of the working memory model? (WMM)

✓ the model explains how memory functions and this has led to useful practical applications.

P: The Working Memory Model (WMM) offers a valuable explanation of memory functioning.

E: Research has demonstrated the significance of the phonological loop, a component of the WMM, in reading development. Specifically, issues with the phonological loop, like difficulties in judging rhyming words, have been identified in children with dyslexia.

A: This illustrates the practical applicability of the WMM in real-life situations. Understanding the deficits in the phonological loop provides insights for devising effective strategies to assist children with dyslexia in overcoming their reading difficulties.

What is a limitation of the working memory model? (WMM)

✘ lack of clarity over the episodic buffer

P: One criticism of the episodic buffer (EB) in the working memory model (WMM) is the lack of understanding regarding its specific functions.

E: The EB was introduced later, in 2000, to address limitations in the original model and resolve the "binding problem." (challenge of explaining how the brain integrates different types of sensory information, such as sight and sound, into a single, unified perception of an event.)

A: Despite this, the EB does seem to have face validity, as we generally do not perceive the elements of an event, such as visual and auditory aspects, in isolation. Instead, we experience events as coherent and sequentially ordered.

L: This suggests that the EB plays a role in integrating phonological and visual information into a unified, time-stamped memory, providing evidence for its existence within the WMM.

What is interference as an explanation for forgetting?

- Interference serves as a cause of forgetting in long-term memory (LTM).

- Information in LTM is essentially permanent; forgetting stems from difficulty accessing rather than loss of information.

- occurs when the retrieval of a memory is disrupted by the presence of other competing or similar information

- interference suggests that memories may interfere with each other, making it challenging to recall specific information

What is PROACTIVE interference?

occurs when OLD existing memories affects attempts to recall something NEW i.e. the memory of an old telephone number disrupts attempts to recall a new phone number.

What is RETROACTIVE interference?

occurs when newly learned information (NEW memories) affects the recall of existing memories (OLD MEMORIES) i.e. the memory of your new car registration number prevents recall of a previous one.

What are the effects of similarity with both types of interference?

• In both cases (proactive and retroactive) interference is more likely to occur when the conflicting information is more similar to one another.

• For example, interference is likely to be greater when revising French and then Spanish than there would be when revising Maths and then English.

What is a strength of interference as an explanation for forgetting?

✓ evidence from laboratory experiments clearly demonstrates interference in memory

P: one strength of interference is that experiments provide clear evidence of interference in memory.

E: For example, in Peterson and Peterson's study, participants recalled trigrams after counting backward by 3's for varying durations. As time elapsed, recall worsened, indicating interference caused by the counting task impairs the participants' ability to retain and retrieve the trigrams accurately

A: This is a strength because lab experiments offer control over extraneous variables, establishing cause-and-effect relationships, thus having high internal validity

L: as a result, this strengthens the validity of interference theory as a plausible explanation for forgetting.

What is a limitation of interference as an explanation for forgetting?

✘ research into interference relies on the use of artificial materials

P: A limitation of research into interference is that it relies on the use of artificial materials

E: The stimulus materials used in studies of interference involve learning lists or words or trigrams. This is artificial as it is far from the things we actually learn and try to remember in real life; people's faces, ingredients for our favourite cake etc.

• Interference may not be the best explanation for forgetting in real life.

A: This is a weakness of interference theory because the use of artificial tasks makes interference much more likely in the lab than in real life, thus making it less generalisable to the wider population (lower external/ecological validity).

• The counterargument to this criticism is that interference effects have been observed in everyday situations and in real life experiments, thus supporting its validity.

What is a strength of interference as an explanation for forgetting?

✓ real-life studies have supported interference

P: A strength of the interference theory is that it is supported by real life research.

E: For example, Baddelely and Hitch (1977) investigated interference effects in an every day setting of rugby players.

• Rugby players were asked to recall the names of the teams they had played over the season. Those who had played fewer games (because they had missed several through injury) recalled more teams than those who had played all season

• Those who played all season will have more interference and had more team names to confuse so poorer recall could be due to retroactive interference.

A:This study shows that interference explanations can apply to at least some every day situations.

What is a strength of interference as an explanation for forgetting?

✓ interference has real life practical applications

• A strength of interference is that it has real life practical applications

• There is evidence for interference exisiting in real world settings. For example, you may struggle to remember your french vocabulary if you later start learning german. This implies that students should not revise similar subjects close to each other as they may disrupt each other.

• The fact that interference has provided many useful practical applications in terms of improving revision adds validity to the idea that real life forgetting might be the result of interference from similar material.

retrieval failure

the inability to recall long-term memories because of inadequate or missing retrieval cues

- cue-dependent forgetting occurs when insufficient cues are available during recall.

It may seem like forgetting, but it's actually retrieval failure.

- the information remains in long-term memory but is temporarily inaccessible

cue

any stimulus that triggers memory

What is the encoding specificity principle? (retrieval failure)

Tulving's suggestion: the closer the retrieval cue is to the original cue, the more effective it is.

ESP's suggestion: Forgetting is more likely if cues during encoding differ from those during retrieval.

• The ESP states that you are more likely to forget if the cues available during encoding are different to those during retrieval.

meaningful cues

Some cues are linked to the material in a meaningful way, aiding recall, e.g 'STM' cue leading to the recall of information about short-term memory.

non-meaningful cues

some cues are present during encoding but not linked to the material e.gContext-dependent forgetting (external cues) and state-dependent forgetting (internal cues)

What is state-dependent forgetting?

being in a different mood/state of arousal may inhibit memory (internal)