The Multi-store Model of Memory

Welcome to the Multi-store Model of Memory!

Hi there! Have you ever wondered why you can remember your childhood pet’s name but forget a phone number three seconds after someone tells it to you? In this chapter, we are going to explore the Multi-store Model of Memory (MSM). This model helps us understand that memory isn't just one single "bucket" in our heads; it’s actually a system of different "stores" that work together to process information.

Don't worry if this seems a bit scientific at first—we’ll break it down step-by-step with plenty of examples!

1. What is the Multi-store Model?

Psychologists Atkinson and Shiffrin suggested that memory is made up of three separate parts, or "stores." Think of it like a computer system: you have a keyboard for input, a temporary clipboard for things you just copied, and a giant hard drive for permanent storage.

The information flows through these three stores in a specific order:
1. Sensory Store
2. Short-term Memory (STM)
3. Long-term Memory (LTM)

Quick Review: The Three Key Features

To understand each store, we look at three things:
• Duration: How long the information stays there.
• Capacity: How much information the store can hold.
• Encoding: The "format" the information is stored in (e.g., sound, pictures, or meaning).

Key Takeaway: The Multi-store Model says memory is a linear process where information moves from the senses into short-term storage, and then into long-term storage.

2. The Three Stores: A Closer Look

The Sensory Store

This is the first "room" information enters. It catches everything your senses pick up (sight, sound, smell, etc.).
• Duration: Very brief (less than 2 seconds).
• Capacity: Very large (it takes in everything around you).
• Encoding: Sense-specific (e.g., visual info stays as an image, sound info stays as a sound).

Analogy: It’s like a sparkler moving in the dark. You see a "trail" of light for a split second after the sparkler has passed. That "trail" is your sensory memory holding onto the image.

Short-term Memory (STM)

If you pay attention to something in the sensory store, it moves here. This is your "working" memory.
• Duration: About 18 to 30 seconds.
• Capacity: Limited (about 7 "items," plus or minus 2).
• Encoding: Mainly acoustic (we tend to repeat things to ourselves silently to remember them).

Did you know? You can keep info in your STM longer by using rehearsal (repeating a pizza shop's phone number over and over until you dial it).

Long-term Memory (LTM)

If you rehearse information enough, it moves to the LTM.
• Duration: Potentially a lifetime.
• Capacity: Infinite (your brain never "fills up").
• Encoding: Mainly semantic (based on the meaning of the information).

Key Takeaway: Information only moves from Sensory to STM if you pay attention, and only moves from STM to LTM if you use rehearsal.

3. Forgetting: Why do we lose information?

The Multi-store Model also explains why we forget things at different stages. The syllabus highlights three types:
• Decay: This happens in the Sensory Store or STM. If you don't pay attention or rehearse, the memory simply fades away over time.
• Displacement: This happens in the STM. Because the STM only has about 7 "slots," new information can "push out" the old information.
• Retrieval Failure: This happens in the LTM. The memory is still there, but you lack the "cues" (like a hint or a specific smell) to find it. It's like having a book in a library but no catalog to tell you which shelf it's on.

Common Mistake to Avoid: Don't confuse displacement with decay. Displacement is about the store being "full," while decay is about time passing.

4. Core Study: Clive Wearing (Wilson, Kopelman and Kapur, 2008)

To prove that STM and LTM are separate stores, psychologists look at people with brain damage. Clive Wearing is a famous example.
Clive suffered from a brain infection that damaged his hippocampus. This resulted in severe anterograde amnesia (the inability to form new memories).

How this supports the Multi-store Model:
• Clive’s STM stayed mostly normal (he could hold a conversation for about 20 seconds).
• However, he could not transfer that information into his LTM.
• This proves that STM and LTM are separate stores because one can be broken while the other still works!

Key Takeaway: The Clive Wearing study is powerful evidence because it shows that damage to specific parts of the brain (the hippocampus) can stop information from moving between memory stores.

5. Criticisms of the Multi-store Model

While this model was a great starting point, it has some flaws that you need to know for your exam:
• Rehearsal vs. Meaning: The model says you only remember things through rehearsal (repetition). However, in real life, we often remember things because they are shocking, funny, or meaningful, even if we never rehearse them.
• Too Simple: Many psychologists believe STM and LTM aren't just single "boxes" but are actually made up of several different parts (for example, separate sections for sounds and visual images).

Quick Review Box: Memory Summary Table

Store: Sensory | Duration: < 2 secs | Capacity: Large | Encoding: Sense-specific
Store: STM | Duration: 18-30 secs | Capacity: 7 +/- 2 items | Encoding: Acoustic
Store: LTM | Duration: Lifetime | Capacity: Infinite | Encoding: Semantic

Final Encouragement: Memory can be a lot to take in (pun intended!), but just remember the "Three Stores" and how information flows between them. You've got this!