Coding, Capacity and Duration of Memory

Your memory works like a filing system with different storage methods. Coding refers to how information gets stored - your short-term memory prefers sounds (acoustic coding), whilst long-term memory focuses on meaning (semantic coding). Baddeley proved this by showing people struggle more with similar-sounding words when recalling immediately.

Capacity is about how much you can store. Miller found that short-term memory holds about 7±2 items (think phone numbers), whilst long-term memory is unlimited. The magic number 7 appears everywhere in life - days of the week, deadly sins - suggesting we're naturally wired for this amount.

Duration tells us how long memories last. Without rehearsal, short-term memories fade in 18-30 seconds (Peterson's research), but long-term memories can last decades. Bahrick studied people recognising old classmates and found impressive recall even after 46 years.

Quick Tip: Use chunking (grouping information) to beat the 7±2 limit - instead of remembering 07123456789, think 0712-345-6789.

The Multi-Store Model of Memory

The Multi-Store Model by Atkinson and Shiffrin shows memory as three connected storage systems. Information flows from your senses → short-term memory → long-term memory, but only if you pay attention and rehearse properly.

Your sensory register captures everything around you for half a second - sights, sounds, smells. Most gets binned unless you actively notice it. Short-term memory holds about 7 items for 30 seconds through maintenance rehearsal (repeating information). With enough rehearsal, memories transfer to long-term storage where they can last forever.

The model explains why cramming doesn't work brilliantly - without proper rehearsal and meaning-making, information just disappears. However, it's oversimplified because it treats short-term and long-term memory as single units, when research shows they're actually more complex.

Study Smart: The model suggests rehearsal gets information into long-term memory, but elaborative rehearsal (connecting new info to existing knowledge) works better than just repetition.

The Working Memory Model

Baddeley and Hitch revolutionised our understanding by showing that short-term memory isn't just one system - it's more like a mental workspace with different components. The central executive acts as your brain's manager, directing attention and controlling three 'slave systems'.

The phonological loop handles sounds and speech - it's why you can rehearse a phone number in your head. The visuo-spatial sketchpad processes visual and spatial information, like remembering where you parked your car. The episodic buffer was added later to integrate different types of information and link working memory to long-term memory.

This model explains why you can listen to music whilst doing visual puzzles (different systems) but struggle to have a conversation while reading (same system overload). Brain imaging studies support this - different areas activate when processing different types of information.

Memory Hack: Use the dual-task principle - combine visual notes with verbal explanations to maximise your working memory capacity during revision.

Types of Long-Term Memory

Tulving discovered that long-term memory isn't one giant storage unit - it's actually three distinct types. Episodic memory stores your personal experiences with specific details about when and where they happened, like your first day at college or last night's dinner.

Semantic memory contains general knowledge and facts about the world - knowing that London is England's capital or understanding what 'psychology' means. Procedural memory holds your learned skills like riding a bike, typing, or playing guitar.

The key difference is consciousness - you must actively recall episodic and semantic memories, but procedural memories work automatically. Brain scan studies show these memories activate different regions, proving they're genuinely separate systems.

Real-World Evidence: Case studies like HM and Clive Wearing show how brain damage can destroy episodic memory whilst leaving procedural and semantic memory intact - they could still play instruments but couldn't remember visitors from minutes earlier.

Explanations for Forgetting: Interference

Interference happens when memories clash and block each other - it's like trying to remember multiple WiFi passwords and getting them mixed up. There are two types: retroactive interference (new memories blocking old ones) and proactive interference (old memories blocking new ones).

McGeoch and McDonald proved that similarity increases interference. When people learned two lists of similar words, recall plummeted compared to learning different types of material. This explains why studying similar subjects back-to-back (like History and Politics) can cause confusion.

Lab studies consistently demonstrate interference effects, giving the theory strong experimental support. However, most research uses artificial word lists rather than meaningful information, which limits how well findings apply to real-world learning and forgetting.

Study Strategy: Space out similar subjects in your revision timetable and use distinctive contexts to reduce interference between topics.

Explanations for Forgetting: Retrieval Failure

Sometimes forgetting isn't about losing memories - you just can't access them without the right retrieval cues. Tulving's Encoding Specificity Principle suggests that matching your learning and recall environments dramatically improves memory performance.

Context-dependent forgetting occurs when external cues don't match. Godden and Baddeley's famous underwater study showed divers recalled words better when learning and testing happened in the same environment (both underwater or both on land). State-dependent forgetting involves internal cues like mood or alertness levels.

Carter and Cassaday found 40% better recall when people's internal states matched between learning and testing. This explains why revising in exam-like conditions or returning to the same mindset can trigger forgotten memories.

Exam Tip: Revise in conditions similar to your exam environment - same time of day, similar lighting, even the same pen type can serve as retrieval cues.

However, these effects work better for recall than recognition tasks, suggesting retrieval failure explains only certain types of forgetting rather than being a universal mechanism.

Factors Affecting Accuracy of EWT: Misleading Information

Eyewitness testimony can be seriously unreliable due to misleading information that distorts original memories. Loftus and Palmer's groundbreaking research showed how the wording of questions influences what people remember about events they've witnessed.

When participants watched car crash footage, those asked about cars that "smashed" into each other estimated speeds 8.7mph higher than those asked about cars that "contacted" each other. Even more dramatically, people who heard "smashed" were more likely to report seeing broken glass that wasn't actually there.

Post-event discussions between witnesses can also contaminate memories. Gabbert found that 71% of people incorporated incorrect details from conversations with other witnesses, compared to 0% of those who worked alone. This memory conformity happens because we assume others remember correctly or feel social pressure to agree.

Critical Thinking: These findings have huge implications for criminal justice - eyewitness testimony might be less reliable than we assume, especially when witnesses have discussed events together.

Factors Affecting Accuracy of EWT: Anxiety

Anxiety has complex effects on eyewitness memory - it can either help or hinder accuracy depending on the situation. Johnson and Scott demonstrated anxiety's negative effects using their famous "weapon focus" study, where people shown a bloody knife had 16% worse recall than those shown a harmless pen.

The weapon focus effect explains this through tunnel vision - high anxiety narrows attention to threatening stimuli, reducing memory for other details. However, real-world studies tell a different story. Yuille and Cutshall found that witnesses to an actual shooting had excellent recall months later, with highly anxious witnesses performing 11% better than those with low anxiety.

This contradiction relates to the Yerkes-Dodson Law - moderate anxiety can enhance performance, but extreme levels impair it. Flashbulb memories of emotionally significant events can be incredibly vivid and detailed due to enhanced memory consolidation during trauma.

Research Reality Check: Lab studies using fake scenarios might not capture the complexity of real-world traumatic events, where survival instincts and emotional significance can actually strengthen memory formation.

Improving EWT Accuracy: Cognitive Interviews

The cognitive interview technique was developed to help police gather more accurate witness statements. It uses four main stages: report everything (even seemingly trivial details), reinstate the context (environment, weather, mood), change perspective (recall from different viewpoints), and reverse the order (recall events backwards).

The Enhanced Cognitive Interview adds social dynamics training - teaching interviewers when to make eye contact, how to build rapport, and creating comfortable environments. These improvements recognise that witness cooperation and emotional state significantly affect recall quality.

Research shows cognitive interviews increase correct recall by 81%, making them genuinely useful for investigations. However, they also increase incorrect recall by 61%, creating a trade-off between quantity and accuracy that investigators must consider.

Practical Application: The most effective elements are context reinstatement and reporting everything - even basic training in these techniques can improve witness interviews without requiring extensive specialist skills.

The technique requires significant training time and specialist skills that many police forces can't provide, limiting its practical implementation despite proven effectiveness.