Memory – How does your memory work?

Welcome to Topic 2: Memory – How does your memory work?

Ever wondered why you can remember the lyrics to a song from five years ago but forget what you had for breakfast yesterday? In this chapter, we are going to dive into the fascinating world of human memory. We’ll explore how your brain acts like a computer to process information, why we sometimes forget things, and the famous experiments that helped psychologists understand it all. Don’t worry if some of the names or theories seem tricky at first – we will break them down into bite-sized pieces!

1. The Basics: Information Processing

Psychologists often compare the human brain to a computer. We don’t just "record" things; we process information through a specific journey. There are six key stages you need to know:

1. Input: This is the information that comes into your brain from the environment through your senses (like sight or sound).
2. Encoding: This is the process of changing information into a format that the brain can store. For example, turning sounds into acoustic patterns.
3. Processing: This is what the brain does with the information while it is being used or changed.
4. Storage: Keeping the information in your brain for a period of time.
5. Retrieval: Finding the stored information and bringing it back into your mind when you need it.
6. Output: The final result—this could be a behavior, like saying an answer out loud in class.

Quick Review: The Memory Journey

Think of it like a library: The book arrives (Input), the librarian gives it a barcode (Encoding), it's put on a shelf (Storage), you look for it later (Retrieval), and finally, you read it (Output).

Key Takeaway: Memory is an active process of taking in, storing, and finding information again.

2. Short-Term vs. Long-Term Memory

Not all memories are stored in the same way. We have two main "buckets" for memories:

Short-Term Memory (STM): This is for things you are thinking about right now.
- Capacity: Very limited. It can only hold about 5 to 9 items.
- Duration: Very short. Information usually disappears in about 18 to 30 seconds unless you repeat it (rehearse it).

Long-Term Memory (LTM): This is your brain's permanent storage.
- Capacity: Potentially infinite! There is no known limit to how much you can remember.
- Duration: Can last a lifetime.

Key Takeaway: STM is like a sticky note (quick and small), while LTM is like a massive hard drive (permanent and huge).

3. Forgetting: Understanding Amnesia

Sometimes, the memory system breaks down due to injury or illness. This is called amnesia. You need to know two types:

Retrograde Amnesia

This is when a person cannot remember things that happened before their brain injury. They might forget who they are or where they live, but they can still make new memories.
Memory Aid: "Retro" means "back"—you can't look back at your old memories.

Anterograde Amnesia

This is when a person cannot make new memories after the brain injury. They can remember their childhood perfectly, but they might forget a conversation they had just two minutes ago.
Memory Aid: "A" for Anterograde = "A" for After. You can't remember what happens after the injury.

Key Takeaway: Retrograde affects the past; Anterograde affects the ability to create a future.

4. The Theory of Reconstructive Memory (Bartlett, 1932)

Sir Frederic Bartlett argued that memory isn't like a video camera. Instead, we "rebuild" our memories every time we recall them. We use Schemas to help us.

What are Schemas?
Schemas are "mental parcels" or shortcuts based on our past experiences and expectations. For example, you have a "classroom schema" (desks, a board, a teacher). If you see a new classroom, your schema helps you understand what it is instantly.

How do Schemas influence memory?
When we remember an event, we fill in the "gaps" using our schemas. This can lead to memories being changed or distorted so they make more sense to us.

Key Study: Bartlett (1932) "War of the Ghosts"

Aim: To see if people would change an unfamiliar story to fit their own schemas.
Procedure: Participants read a Native American ghost story that was full of strange details. They were then asked to retell it several times over weeks or months.
Findings: The story changed! Participants shortened it, changed "canoes" to "boats," and left out the supernatural parts that didn't make sense to them.
Conclusion: Memory is reconstructive. We change information to fit our cultural expectations.

Evaluation of Bartlett’s Theory

Strength: It has real-world application. It explains why eyewitnesses in court often give incorrect or biased accounts.
Weakness: The study was unscientific. Bartlett didn't use a standardized procedure, so it's hard to replicate exactly.

Key Takeaway: We don't just remember; we reconstruct based on what we expect to see.

5. The Multi-Store Model of Memory (Atkinson and Shiffrin, 1968)

This is a very famous theory that describes memory as a flow of information through three stages:

1. Sensory Register: Information from your senses (eyes, ears) enters here. It only stays for a fraction of a second. If you pay attention, it moves to the next stage.
2. Short-Term Memory (STM): If we pay attention, info stays here for up to 30 seconds. If we use rehearsal (repeating it), it stays there longer and eventually moves to LTM.
3. Long-Term Memory (LTM): Once info is rehearsed enough, it is stored permanently. To use it, we retrieve it back into our STM.

Key Study: Peterson and Peterson (1959)

Aim: To see how long information stays in STM without rehearsal.
Procedure: Participants were shown "trigrams" (3 letters like K-Z-J). They were then asked to count backward in 3s (to stop them from rehearsing) for different amounts of time before being asked to remember the letters.
Findings: After \(3\) seconds, they remembered about 80%. After \(18\) seconds, they remembered less than 10%.
Conclusion: Without rehearsal, the duration of STM is very short (less than 18-30 seconds).

Evaluation of the Multi-Store Model

Strength: It is supported by scientific research (like Peterson and Peterson) which shows that STM and LTM are truly different.
Weakness: It is too simple. It suggests that rehearsal is the only way to get things into LTM, but we often remember exciting things without any rehearsal at all!

Key Takeaway: Information flows from senses -> STM -> LTM, but only if we pay attention and repeat it.

6. Issues and Debates: Reductionism vs. Holism

In Psychology, there is a big debate about how we should study humans. This applies to memory too!

Reductionism: This is the idea that to understand something complex (like memory), you should break it down into simple, separate parts.
- Example: The Multi-Store Model is reductionist because it breaks memory down into three simple "boxes."
- Strength: It's easier to test in a lab.
- Weakness: It might miss the "big picture" of how memory works in real life.

Holism: This is the idea that you should look at the "whole" person or the "whole" system, rather than just the parts.
- Example: Bartlett’s Reconstructive Theory is more holistic because it looks at how our whole background, culture, and feelings affect our memory.
- Strength: It's more realistic.
- Weakness: It is very hard to test scientifically because so many things are happening at once.

Key Takeaway: Reductionists look at the gears of the clock; Holists look at the whole clock and the time it tells.

Final Study Tip!

To move these notes from your Short-Term Memory into your Long-Term Memory, you need to use Rehearsal! Try explaining the difference between Anterograde and Retrograde amnesia to a friend or family member today. You’ve got this!