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Unlock This CourseThe Multistore Model of memory, proposed by Atkinson and Shiffrin in 1968, suggests that memory works like a computer with three separate stores: sensory memory, short-term memory and long-term memory. But how do we know this model is accurate? Scientists have gathered lots of evidence over the years that supports this three-store system.
Think of it like having three different boxes for storing your stuff - a temporary tray by the door (sensory memory), a small desk drawer (short-term memory) and a huge storage room (long-term memory). Each box works differently and has different rules about what goes in and how long things stay there.
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One of the strongest pieces of evidence comes from the serial position effect. When people try to remember a list of words, they're much better at remembering the first few words (primacy effect) and the last few words (recency effect), but struggle with the middle ones. This creates a U-shaped curve when you plot it on a graph - brilliant evidence for separate memory stores!
Scientists have conducted hundreds of experiments that support the idea of separate memory stores. The evidence comes from different types of research - laboratory experiments, brain scans and studies of people with brain damage.
Glanzer and Cunitz (1966) conducted a famous experiment that really showed off the multistore model. They gave participants lists of words to remember and tested their recall immediately or after a delay. The results were fascinating and provided strong support for separate memory stores.
When tested straight away, participants showed both primacy and recency effects - they remembered the first and last words best. This suggests the first words had moved to long-term memory, whilst the last words were still fresh in short-term memory.
After a 30-second delay (filled with counting backwards), the recency effect disappeared but the primacy effect remained. This shows that short-term memory had been cleared, but long-term memory stayed intact - exactly what the multistore model predicts!
The different patterns of recall provide clear evidence for separate memory stores. If memory was just one system, we wouldn't see these distinct effects. The experiment shows that information really does move through different stores with different characteristics.
Henry Molaison (known as Patient HM) had brain surgery in 1953 to treat severe epilepsy. The surgery removed parts of his hippocampus, leaving him unable to form new long-term memories. However, his short-term memory remained perfectly normal - he could hold conversations and remember things for a few minutes. This case study provides powerful evidence that short-term and long-term memory are separate systems stored in different parts of the brain.
Modern brain scanning techniques have given us amazing insights into how memory works. When scientists scan people's brains whilst they're doing memory tasks, they can see which parts of the brain are active. This has provided strong biological evidence for the multistore model.
Brain imaging studies have shown that different types of memory tasks activate different brain regions. This neurological evidence strongly supports the idea that memory isn't just one system, but several separate ones working together.
When people are doing short-term memory tasks (like remembering a phone number for a few seconds), brain scans show activity in the prefrontal cortex. This area is like the brain's workspace - it's where we consciously hold and manipulate information for brief periods.
Long-term memory formation and retrieval shows activity in the hippocampus and surrounding areas. These regions are like the brain's filing system - they're responsible for storing information permanently and helping us retrieve it when needed.
Another strong argument for the multistore model comes from studies showing that short-term and long-term memory have very different characteristics. If memory was just one system, we'd expect it to work the same way all the time - but it doesn't!
George Miller (1956) discovered that short-term memory has a very limited capacity - most people can only hold about 7 (plus or minus 2) items at once. This is why phone numbers are usually 7 digits long! Long-term memory, on the other hand, seems to have unlimited capacity. This huge difference in capacity suggests they're completely separate systems.
Try this yourself: get someone to read you a list of random numbers, starting with 3 numbers, then 4, then 5 and so on. Most people start to struggle when the list gets to 7 or 8 numbers. This simple test demonstrates the limited capacity of short-term memory that Miller identified. It's used by psychologists today to assess memory function.
Conrad (1964) provided another piece of evidence by showing that short-term and long-term memory store information in different ways. This is called 'coding' - it's like using different languages to store the same information.
Conrad found that short-term memory stores information based on how things sound (acoustic coding). When people made mistakes recalling letters, they confused letters that sounded similar (like B and P) rather than letters that looked similar. This shows STM is like having a voice in your head repeating information.
Long-term memory, however, stores information based on meaning (semantic coding). When recalling information from long-term memory, people are more likely to confuse words with similar meanings rather than similar sounds. This shows LTM organises information by what it means, not how it sounds.
Some of the most compelling evidence for separate memory stores comes from studying people with memory problems. These natural experiments show us what happens when different parts of the memory system are damaged.
Different types of amnesia affect different memory stores, providing clear evidence that they're separate systems. It's like having different keys for different locks - damage to one system doesn't necessarily affect the others.
This affects the ability to form new long-term memories whilst leaving short-term memory intact. Patients can have normal conversations but can't remember meeting you five minutes later. This shows STM and LTM are separate systems.
This affects old long-term memories whilst leaving short-term memory and the ability to form new memories intact. Patients might forget their past but can still function normally day-to-day. Again, this shows the stores are separate.
The fact that brain damage can affect one type of memory whilst leaving others intact is strong evidence for separate memory stores. If memory was one unified system, we'd expect all types of memory to be affected equally.
Clive Wearing is a musician who developed severe anterograde amnesia after a brain infection in 1985. He can only remember things for about 20 seconds, constantly feeling like he's just woken up. However, he can still play piano beautifully and remembers how to read music. This shows that different types of long-term memory (procedural vs episodic) are stored separately, supporting the idea of multiple memory systems.
The evidence we've looked at shows several key strengths of Atkinson and Shiffrin's model. It's not perfect, but it does explain a lot about how memory works and has been incredibly influential in psychology.
The model is backed by decades of research using different methods - laboratory experiments, brain scans and case studies all point to the same conclusion. This convergent evidence makes the model very credible and reliable.
Understanding separate memory stores has led to practical applications in education, therapy and everyday life. Teachers use techniques based on the model to help students learn more effectively and therapists use it to help people with memory problems.
The multistore model has stood the test of time because it's supported by so much evidence from different sources. Whilst newer models have added more detail and complexity, the basic idea of separate memory stores remains a fundamental principle in psychology. The evidence from serial position effects, brain imaging, capacity studies, coding differences and clinical cases all point to the same conclusion: memory isn't one system, but several separate stores working together.