Memory: Models, Types & Forgetting
Cognitive psychology examines how human memory encodes, stores, and retrieves information. This guide covers Atkinson and Shiffrin's Multi-Store Model, Baddeley and Hitch's Working Memory Model, types of long-term memory, explanations for forgetting (interference and retrieval failure), and factors affecting eyewitness testimony.
- Short-Term Memory (STM)
- A temporary store for memory holding around 7 (±2) items for up to 30 seconds, encoding mainly acoustically.
- Long-Term Memory (LTM)
- A potentially permanent memory store with unlimited capacity, encoding primarily semantically.
- Working Memory Model
- Baddeley and Hitch's model replacing the unitary STM, consisting of the central executive, phonological loop, visuo-spatial sketchpad, and episodic buffer.
Memory: Models, Types & Forgetting: Situational Variables & Memory Encoding Simulator
Explore how situational variables alter human behaviour in controlled experiments or test cognitive rehearsal pathways.
Obedience to 450V: 65% (vs. 65% Baseline)
65% of participants obeyed all the way to the maximum 450V shock when the experimenter wore a grey lab coat at Yale University.
Exam notes: Multi-Store Model (MSM), Working Memory Model (WMM), Forgetting & Eyewitness Testimony
- When comparing the Multi-Store Model (Atkinson & Shiffrin 1968) and the Working Memory Model (Baddeley & Hitch 1974), highlight that MSM treats Short-Term Memory (STM) as a single passive unitary store, whereas WMM divides STM into active, independent slave systems controlled by the Central Executive.
- Always memorise the 3 properties (Coding, Capacity, Duration) for every store in MSM: Sensory Register (modality-specific coding, huge capacity, <0.5 sec duration: Sperling 1960); STM (acoustic coding: Baddeley 1966a, 7±2 items or 4 chunks: Jacobs/Miller, 18-30 sec duration: Peterson & Peterson 1959); LTM (semantic coding: Baddeley 1966b, unlimited capacity, up to a lifetime duration: Bahrick 1975).
- Case Study KF (Shallice & Warrington 1970) is double-barrelled AO3 evidence: KF had damaged verbal STM (Phonological Loop) after a motorcycle accident yet intact visual STM (Visuo-Spatial Sketchpad), proving STM is not a single unitary store (refuting MSM and supporting WMM).
- In Eyewitness Testimony (Loftus & Palmer 1974), 'smashed' produced a mean speed estimate of 40.5 mph vs 31.8 mph for 'contacted', explained by either Response-Bias (wording merely shifts how the witness reports the speed) or Substitution Explanation (the leading question permanently alters the memory trace in LTM).
| Memory Store | Coding, Capacity & Duration | Landmark Experimental Study |
|---|---|---|
| Sensory Register (Iconic / Echoic) | Modality-specific (visual/auditory) · Very high capacity (millions of receptors) · < 0.5 seconds | Sperling (1960): 4×3 letter grid flashed for 50ms; partial report cued by tone recalled 75% vs 33% whole report |
| Short-Term Memory (STM) | Acoustic coding · 7 ± 2 items (5-9 items / 4 chunks) · 18 to 30 seconds without rehearsal | Peterson & Peterson (1959): consonant trigrams + counting backwards in 3s; 80% recall at 3s fell to <10% at 18s |
| Long-Term Memory (LTM) | Semantic coding · Unlimited capacity · Up to a lifetime (decades) | Bahrick et al. (1975): high-school yearbook recognition 90% accurate after 15 years and 70% after 48 years |
| Working Memory Slave Systems | Phonological Loop (2 seconds speech) · Visuo-Spatial Sketchpad (3-4 objects) · Episodic Buffer | Baddeley et al. (1975): dual-task interference only occurs when two tasks compete for the same slave system |
Key Concepts & Exam Definitions (7)
- Short-Term Memory (STM)
- A temporary store for memory holding around 7 (±2) items for up to 30 seconds, encoding mainly acoustically.
- Long-Term Memory (LTM)
- A potentially permanent memory store with unlimited capacity, encoding primarily semantically.
- Working Memory Model
- Baddeley and Hitch's model replacing the unitary STM, consisting of the central executive, phonological loop, visuo-spatial sketchpad, and episodic buffer.
- Proactive Interference
- When older memories interfere with the retrieval of newly learned information.
- Cognitive Interview
- A police technique for interviewing witnesses to a crime, using psychological principles to improve memory recall.
- Proactive vs Retroactive Interference
- Proactive Interference (PI) occurs when an OLD memory disrupts recall of a new memory (past-to-present, e.g. calling your new partner by your ex's name). Retroactive Interference (RI) occurs when new learning disrupts recall of an OLD memory (McGeoch & McDonald 1931: interference is strongest when the two materials are similar).
- Context-Dependent vs State-Dependent Forgetting
- According to Tulving's Encoding Specificity Principle, retrieval failure occurs when cues present at encoding are absent at recall. Godden & Baddeley (1975) showed deep-sea divers recalled 40% more words when learning and recall matched (land-land or underwater-underwater = external context); Carter & Cassaday (1998) showed the same for internal physiological state (antihistamine vs placebo).
Quick-Fire Flashcards (7)
Click any card to check the answer, then mark it as Known to track your progress.
What is the capacity of Short-Term Memory (STM)?
How is Long-Term Memory (LTM) primarily encoded?
What are the three types of LTM?
Which part of the Working Memory Model coordinates the sub-systems?
Define Retroactive Interference.
What are the four components of Baddeley & Hitch's Working Memory Model (including the 2000 addition)?
What are the four stages of Geiselman & Fisher's Cognitive Interview (CI)?
Exam-Style Questions & Mark Schemes (4)
Write or think through your answer first, then click Check Mark Scheme to see the exact points examiners award marks for.
- Q1
Outline the role of the phonological loop in the Working Memory Model.
Click “Check Mark Scheme” to compare your answer, The phonological loop processes auditory information. It consists of the phonological store (inner ear) which holds words heard, and the articulatory process (inner voice) which allows maintenance rehearsal.
- Q2
Explain one limitation of the Multi-Store Model of memory.
Click “Check Mark Scheme” to compare your answer, It oversimplifies STM and LTM as single, unitary stores. The Working Memory Model proved STM is complex and active, and research (e.g., Clive Wearing) shows multiple types of LTM exist.
- Q3
What is state-dependent forgetting?
Click “Check Mark Scheme” to compare your answer, A form of cue-dependent forgetting where memory retrieval fails because the individual's internal physiological or psychological state at retrieval is different from their state at encoding.
- Q4
Discuss the Working Memory Model (Baddeley and Hitch, 1974). [8 marks]
Click “Check Mark Scheme” to compare your answer, 1) AO1 (3 marks): WMM proposes STM is an active multi-component store. The Central Executive directs attention to three slave systems: the Phonological Loop (processes auditory info via the phonological store and articulatory control process), the Visuo-Spatial Sketchpad (processes visual and spatial info via the visual cache and inner scribe), and the Episodic Buffer (integrates multimodal info and links to LTM). 2) AO3 Clinical Support (2 marks): Shallice & Warrington (1970) studied patient KF, whose verbal STM was severely impaired while visual STM remained intact, proving separate verbal and visual stores exist. 3) AO3 Dual-Task Support (2 marks): Baddeley (1975) showed participants struggled to perform two visual tasks simultaneously but easily performed one visual and one verbal task together, supporting separate slave systems with limited capacity. 4) AO3 Limitation (1 mark): Even Baddeley (2003) admitted the Central Executive is 'the most important but least understood component' (essentially a vague homunculus).
Common Exam Questions (3)
What is the Multi-Store Model of Memory?
Atkinson and Shiffrin (1968) proposed that memory consists of three separate structural stores: the sensory register, short-term memory (STM), and long-term memory (LTM), with information passing linearly between them via attention and rehearsal.
What is the difference between semantic and episodic memory?
Semantic memory is a store of shared factual knowledge about the world and word meanings, detached from personal context. Episodic memory stores personal, time-stamped experiences of specific events from an individual's life.
What causes forgetting according to interference theory?
Interference theory states that forgetting in long-term memory occurs when two similar sets of information disrupt each other: proactive interference happens when older memories disrupt the recall of new information, whereas retroactive interference happens when new learning disrupts older memories.
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