Cognitive Psychology

Main assumptions of the Cognitive approach

• Humans are information processors.

• Behaviour is influenced by cognitive processes.

• Humans actively organise and manipulate information from the environment.

• The mind functions like a computer — it encodes, stores, and retrieves data to produce behaviour (output).

Four Features of Science

• Empericism

• Objectivity

• Replicability

• Falsification

Empiricism

• Knowledge gained through direct observation or experimentation.

Objectivity

• Research must be unbiased and unaffected by researcher expectations.

Replicability

• Studies should be repeatable, producing consistent results to ensure reliability.

Falsification

• Theories must be testable and capable of being proven false.

Input

• Information enters through the senses (e.g., eyes, ears).

Processing

• Information enters through the senses (e.g., eyes, ears).

Processing

• The brain pays attention, stores, thinks about, and retrieves information using prior knowledge.

Response

• Output may be behaviour, a decision, or an emotional reaction.

3 stores of the MSM

1. Sensory Memory

2. Short-Term Memory (STM)

3. Long-Term Memory (LTM)

Sensory memory

• First store; briefly holds all incoming sensory information.

• Includes iconic (visual) and echoic (auditory) stores.

Duration of STM

• A few seconds; information remains in its original form.

How much of sensory input reaches STM?

• 1%

What is needed for Information to transfer to STM

Attention

Short- Term Memory

• Receives encoded data from sensory memory.

Capacity- STM

• 7 ± 2 items (Miller, 1956)

Duration- STM

15-30 seconds

Encoding- STM

Acoustic

Without maintenance rehearsal, information will…

Decay (fade away), or displace (pushed out by new data)

Chunking

Grouping data into batches

Maintenance rehearsal

• Repeating info to keep it in the the STM or transfer to LTM

Capacity- LTM

Unlimited

Duration- LTM

Potentially lifelong

Encoding- LTM

Semantic

How much of STM information enters LTM?

25%

Retrieval- LTM

Information must move back int STM to be recalled

HM and the MSM (summary)

• HM had his hippocampus removed to treat epilepsy.

• Result: Intact STM, but impaired LTM — could not form new long-term memories.

• Could remember old information, but not new people or events.

• Supports MSM’s idea of separate memory stores (STM and LTM).

Availability Problems

• Information is no longer stored — permanently forgotten.

Accessibility Problems

Memory is stored but temporarily inaccessible.

Miller (1956) aim and procedure

• To investigate the capacity of STM.

• Participants were shown increasing sequences of digits or letters using a tachistoscope.

• They had to recall each sequence in the correct order

Miller (1956)- Findings and conclusio

• Mean span for numbers = 9.3, for letters = 7.3.

• Observed the pattern of 7’s (7 days, 7 notes, 7 sins).

• Concluded that STM capacity is 7 ± 2 items or chunks.

Miller (1956)- Strengths

• High internal validity – confounding variables (e.g., noise) controlled for all participants.

• Controlled lab setting – allowed precise measurement of STM capacity.

• Reliable – standardised procedures, easily replicable.

Miller (1956)- Weaknesses

• Low ecological validity – artificial task (digit/letter recall) unlike real-life memory use.

• Lack of mundane realism – doesn’t reflect how we use STM in daily life.

• Sample bias – may not generalise to wider populations.

Peterson & Peterson- Aim and Procedure

• To test duration of STM without rehearsal.

• Participants memorised nonsense trigrams (e.g., FJT, KPD).

• To prevent rehearsal, they performed a distractor task – counting backwards in threes.

• Recall tested after 3, 6, 9, 12, 15, or 18 seconds

Peterson & Peterson- Findings and Conclusion

• After 3 seconds, ~80% recalled trigrams correctly; after 18 seconds, <10% recalled.

• As delay increased, recall decreased.

• Concluded STM duration is 15–18 seconds without rehearsal.

Peterson & Peterson- Strengths

• High internal validity – same type of meaningless material for all participants, controlled setting.

• Reliable – standardised procedure replicable across trials.

Peterson & Peterson- Weaknesses

• Low ecological validity – artificial task and setting.

• Lacks mundane realism – remembering trigrams unlike real memory use.

• Sample bias – may not represent memory ability of all age groups.

Bradey et al- Aim and Procedure

• To test capacity of LTM using real-life stimuli.

• Participants viewed 2,500 object images over 5.5 hours.

• Later shown image pairs and asked which one they had seen before.

• Comparison conditions: novel, exemplar, or state pairs.

Bradey et al- Results and Conclusion

Accuracy: 92% (novel), 88% (exemplar), 87% (state).

• Participants remembered thousands of detailed images.

• Concluded LTM capacity is extremely large—potentially unlimited.

Brady et al- Strengths

• High ecological validity – used real-world images, more representative of normal memory use.

• Controlled procedure – standardised design allows replication.

Brady et al- Weaknesses

• High ecological validity – used real-world images, more representative of normal memory use.

• Controlled procedure – standardised design allows replication.

Bahrick et al- Aim and Procedure

• To investigate duration of LTM for real-life memories.

• 392 ex-high school students (aged 17–74) tested on memory for classmates.

• Three tests: free recall, name recognition, photo recognition.

Bahrick et al- Results and Conclusions

• Recall remained high for up to 34 years after graduation.

• After 47 years, recall declined.

• Concluded LTM duration is potentially lifelong.

Bahrick at al- Strengths

• High ecological validity – real-life memories (classmates, photos).

• Representative of natural memory use – avoids artificiality of lab tasks.

Bahrick et al.- Weaknesses

• Low internal validity – no control for rehearsal (participants could’ve reviewed yearbooks).

• Confounding variables – individual differences in exposure and memory practice.

Baddeley- Aim and Procedure

• To investigate encoding differences between STM and LTM.

• Four groups learned word lists:

– Group 1: acoustically similar (cat, hat, mat)

– Group 2: acoustically dissimilar

– Group 3: semantically similar (big, large, huge)

– Group 4: semantically dissimilar

• Participants recalled words immediately (STM) or after 20 minutes (LTM).

Baddeley- Findings and Conclusion

• STM: poorer recall for acoustically similar words → encodes acoustically.

• LTM: poorer recall for semantically similar words → encodes semantically.

• Concluded STM and LTM use different encoding systems.

Baddeley- Strengths

• High internal validity – well-controlled conditions (same distractions, timing, etc.).

• Reliable – standardised procedure replicable.

Baddeley- Weaknesses

• Low ecological validity – artificial word lists, not everyday material.

• Lack of mundane realism – limited real-life application.

• Sample bias – often used student participants.

What research supports the MSM’s claim that STM and LTM are qualitatively different?

Baddeley (1966) found that STM encodes acoustically and LTM encodes semantically.

→ This supports the MSM’s view that STM and LTM are separate, independent stores.

Why does supporting research (e.g., Baddeley) increase the validity of the MSM?

It shows real, measurable differences between STM and LTM processing, strengthening the claim that they are distinct systems.

What evidence challenges the MSM’s view that STM is a unitary store?

Shallice & Warrington (1970) – patient KF had poor recall for digits read aloud but better recall when he read them himself.

→ Suggests separate STM stores for visual and auditory information.

Why is the evidence from patient KF a limitation of the MSM?

It shows STM is not one single store, meaning the MSM oversimplifies memory. The Working Memory Model explains this better.

What did Craik & Watkins (1973) discover about rehearsal in memory?

There are two types of rehearsal — maintenance (keeps info in STM) and elaborative (transfers info to LTM).

→ Only elaborative rehearsal leads to long-term storage.

Why is Craik & Watkins’ finding a limitation of the MSM?

The MSM assumes more rehearsal = better long-term memory, but this study shows type of rehearsal matters more, which the model fails to explain.

What was the aim of Glanzer & Cunitz (1966)?

To investigate whether the position of a word in a list affects recall (Serial Position Effect)

What is the Primacy Effect?

The tendency to remember the first few items in a list because they have been rehearsed and transferred to LTM.

What is the Recency Effect?

The tendency to remember the last few items in a list because they are still stored in STM and have not yet decayed.

Why are the middle items in a list often forgotten?

• Rehearsal focuses on first few items, leaving less attention for middle ones.

• By the end, middle items decay or are displaced by newer information in STM.

What happened when participants were given a 30-second interference task in Glanzer & Cunitz (1966)?

The recency effect disappeared because the task displaced items from STM, showing they had decayed.

How does Glanzer & Cunitz’s research support the MSM?

It provides empirical evidence for separate memory stores (STM & LTM) and shows how information transfers via rehearsal.

Who was Clive Wearing, and how does his case support the MSM?

• Suffered brain damage to the hippocampus from a virus.

• Developed anterograde amnesia, unable to form new long-term memories.

• His STM remained intact, supporting that STM and LTM are separate stores.

Who was HM (Henry Molaison), and how does his case support the MSM?

• Underwent surgery removing his hippocampus to treat epilepsy.

• Could not form new LTM but had a normal STM.

• Demonstrates that transfer from STM → LTM depends on the hippocampus and rehearsal process.

What do the case studies of Clive Wearing and HM collectively show?

They provide biological and clinical support for the MSM — proving STM and LTM are distinct and functionally separate systems.

What is the role of the Central Executive (CE)?

• The ‘boss’—monitors incoming data and directs attention.

• Allocates tasks to slave systems (PL, VSS, EB).

• Very limited capacity.

• Modality-free (can process any kind of information).

• No fixed duration.

Weakness of the Central Executive

• Poorly understood—Baddeley (2003) called it the “least understood component.”

• May consist of multiple subcomponents.

• Weakness → reduces overall validity of the WMM.

What is the Phonological Loop (PL)?

• Deals with auditory information and preserves word order (acoustic coding).

Phonological Store –

stores words you hear

Articulatory Process

allows maintenance rehearsal (2 seconds’ worth of what you can say).
• Duration: brief unless rehearsed.

What is the Visuo-Spatial Sketchpad (VSS)?

• Stores visual and spatial information (e.g. imagining layout of your room).

• Capacity: ~3–4 objects (Baddeley, 2003).

• Two parts (Logie, 1995)

Visual Cache

stores visual data

Inner Scribe

Records arrangement of objects.
• Duration: short unless actively used.
• Coding: visual/spatial.

What is the Episodic Buffer (EB)? (Added 2000)

• Links working memory to long-term memory and wider cognitive processes (e.g. perception).

• Temporary storage for the central executive.

• Integrates visual, spatial, and verbal info.

• Maintains sense of time sequencing (records “episodes”).

• Capacity: ~4 chunks (Baddeley, 2012).

What does the dual-task evidence show? (Baddeley et al., 1975)

• Harder to do two visual tasks together than one visual + one verbal task.

•Visual tasks compete for the same slave system.

• Strength: supports existence of a separate visuo-spatial sketchpad.

What does Shallice & Warrington (1970) show about the WMM?

• Case study of KF (brain damage).

• Poor STM for verbal info, but normal for visual info.

• Strength: supports separate visual and auditory stores (PL and VSS)

What is the Word Length Effect? (Baddeley et al., 1975)

• Easier to recall short words than long ones.

• Capacity of articulatory process ≈ 2 seconds.

• Disappears with articulatory suppression

• Strength: supports function of the articulatory process in the PL.

What did Braver et al. (1997) find using brain scans?

• Central Executive tasks → ↑ activity in the left prefrontal cortex (PFC).

• Activity increased as task difficulty rose.

• Strength: supports the WMM through scientific evidence.

What is reconstructive memory?

Memory is an active reconstruction, not a perfect record of events.

• Recall is influenced by what we already know (schemas).

What is a schema?

• A mental framework built from past experiences.

• Guides how we interpret and recall new information.

• Can lead to distortions or false memories.

What does ‘effort after meaning’ mean?

• We interpret and reshape memories to make sense of them based on our experiences.

What is confabulation?

• Filling in memory gaps with made-up details without intent to lie.

• Happens when schemas add or change details to make a story fit expectations.

How are schemas formed?

• Built through experience and knowledge of the world.

• Allow quick information processing by making assumptions about situations.

What is assimilation in schema theory?

• New information is fitted into an existing schema.

What is accommodation in schema theory?

Changing existing schemas to allow in new information.

Omission

Leaving out unfamiliar or unpleasant details.

Rationalisation

adding details to make recall logical.

Transformation

changing details to make them familiar.

Familiarisation

aligning unfamiliar details with existing schemas

Bartlett- Procedure

20 British - (7 women, 13 men) participants.

• Read a North American folk story twice.

• Asked to recall over different periods of time.

• Not told real aim of the study.

Condition one- Serial Reproduction

• PP’s would read the story.

• Retell it 15-30min after to another PP.

• Process continued with second PP.

Condition 2- Repeated reproduction

• PP’S would read the story.

Retell it:

• 15min

• 24hours

• 1week

• 1month

• 1year later

Longest recollection was 6.5 years later.

Condition 2- Results

• 7 participants omitted the title.

• 10 transformed the title to make it more rational (war ghost story).

How did the participants change the story?

• Canoe to boats.

• Hunting seals to fishing.

• Changed names of characters.

Changed to familiar words.

Represented their culture and experiences.

How did the participants use Assimilation/ Confabulation?

Assimilation:

• The story became more consistent with the participant’s own cultural expectations

• Details changed to fit with British norms.

Confabulation:

• New information was added in to fill in a memory, so it makes sense. 

How did the participants use Rationalisation?

• Participants tended to change the order of the story.

• Story became more coherent.

• They also added detail and/or emotions.

How did the participants use Levelling?

The story also became shorter with each retelling.

PP’s omitted information which was seen as not important.

330 → 180 words

Bartlett- Conclusion

• Evidence of the active reconstruction of memory.

• Participants did not recall the story fully or accurately.

• PP’s altered and omitted details that did not fit with their schemas.

Application of Bartlett’s Theory to the Cognitive Interview

Strength – Demonstrates real-world usefulness.
• Improve accuracy with eyewitness testimony.
• Memory reconstruction by schemas could lead to distortion.

Cognitive Interview techniques:

• Context reinstatement.

• Multiple perspectives.

Reduce schema influence.

Encourages recall of specific details rather than relying on general knowledge.

Application of Bartlett’s Theory to False Memories

Strength – Supports how schemas shape and distort memory recall.

• Bartlett’s idea of schemas explains false memories and eyewitness inaccuracies.

2005 De Menezes shooting:

• Witnesses gave exaggerated or inconsistent accounts.

• Their schemas about “terrorist” behaviour altered how they remembered events.