Psychology (9218) | Memory

🧠 Psychology 9218 Study Notes: Memory

Hello future Psychologist! Welcome to the Chapter on Memory.

Have you ever forgotten someone’s name just seconds after meeting them? Or perhaps you remember exactly what you ate for dinner last Tuesday? That's all memory in action!

Memory is one of the most fundamental parts of the section Cognition and behaviour because it’s how we process, store, and recall information. Understanding memory is like getting the instruction manual for your own brain! Don't worry if some concepts seem tricky—we will break them down step-by-step.

Section 1: The Basics of Memory – E.S.R.

Before we look at the big models, let’s understand the three essential steps memory takes. Think of it like making and storing a movie:

1. Encoding (The Camera Recording)

Encoding is the process of getting information into the memory system. It converts sensory information (what you see, hear, taste) into a format the brain can store.
Example: You read a fact in a textbook. Your brain converts the visual words into a meaningful code.

• Acoustic Encoding: Based on sound (remembering a melody).
• Visual Encoding: Based on sight (remembering a face).
• Semantic Encoding: Based on meaning (remembering the concept of a fact, not just the words). This is usually the strongest!

2. Storage (Saving the File)

Storage is keeping the encoded information in your memory over time. This is where the information waits for you to need it later.

3. Retrieval (Playing the Movie)

Retrieval is getting the information back out of storage when you need it (recalling, recognising, or remembering). If you fail retrieval, you "forget."

🔑 Key Takeaway:

Memory is a cycle: Encode it, Store it, Retrieve it.

Section 2: The Multi-Store Model (MSM) of Memory

The Multi-Store Model (MSM), proposed by Atkinson and Shiffrin (1968), is the classic way psychologists explain memory. It suggests that memory is made up of three separate, distinct stores.

Analogy: The Post Office System

Imagine your brain is a large post office.
1. Sensory Register: The large lobby where all incoming mail (information) lands briefly.
2. Short-Term Memory (STM): The small counter where workers quickly process a few items they are actively looking at.
3. Long-Term Memory (LTM): The massive warehouse filing system where items are stored for a very long time.

The Three Stores and Their Characteristics

We must know the Capacity (how much it holds), Duration (how long it holds it for), and Encoding method for each store:

1. The Sensory Register (SR)

This is where all the raw information from your senses (eyes, ears, etc.) enters first.

• Capacity: Very large (can take in everything around you).
• Duration: Very brief (less than half a second for visual info; about two seconds for acoustic info). If you don't pay attention, it's gone!
• Encoding: Sense-specific (visual, acoustic, tactile, etc.).

2. Short-Term Memory (STM)

If you pay attention to information in the SR, it moves here. This is your temporary working space.

• Capacity: Very limited. Psychology suggests the magical number 7 ± 2 items (between 5 and 9 pieces of information).
• Duration: Short (about 18–30 seconds) unless you actively rehearse (repeat) the information.
• Encoding: Mainly acoustic (based on sound). Did you know? If you try to remember a phone number, you often repeat the sounds in your head!

Memory Aid: STM is where you hold a phone number just long enough to dial it.

3. Long-Term Memory (LTM)

If information is rehearsed enough in the STM, it transfers to the LTM. This is our permanent store.

• Capacity: Potentially unlimited—it's enormous!
• Duration: Potentially unlimited (a lifetime).
• Encoding: Mainly semantic (based on meaning). You remember what things *mean*, not just how they sounded.

Section 3: Types of Long-Term Memory (LTM)

Psychologist Endel Tulving suggested that LTM isn't just one big storage space; it’s divided into different categories based on the type of information stored.

1. Episodic Memory (The Diary)

Episodic memory stores memories of personal experiences, events, and specific times and places. These are "episodes" from your life.

• It’s like a mental diary—you recall the emotion, context, and time.
• Example: Remembering your 10th birthday party, or what you ate for breakfast this morning.

2. Semantic Memory (The Textbook)

Semantic memory stores factual knowledge, concepts, meanings, and information about the world.

• It’s like a mental encyclopedia—it’s general knowledge that isn't tied to when you learned it.
• Example: Knowing that Paris is the capital of France, or that 2 + 2 = 4.

3. Procedural Memory (The Skills)

Procedural memory stores the memory of how to do things—skills, actions, and habits. These memories are often recalled without conscious thought (muscle memory).

• It's often hard to explain these skills in words, you just *do* them.
• Example: Knowing how to ride a bicycle, tie your shoelaces, or type on a keyboard.

Memory Aid: Think P.E.S.
Procedural (Skills)
Episodic (Events)
Semantic (Facts)

🔑 Key Takeaway:

Tulving showed that LTM is more complex than a single box, separating facts, events, and skills.

Section 4: Explanations for Forgetting

We all forget things. But why does this happen? Psychologists suggest two main reasons for why memories fail to be retrieved from LTM: Interference and Cue-Dependent Forgetting.

1. Interference Theory

Interference happens when two pieces of information clash with each other, causing one or both memories to be distorted or forgotten. This is common when the two pieces of information are very similar (like learning two different languages close together).

A. Proactive Interference (P.O.N.)

Previously learned information Onterferes (gets in the way of) New learning.

• Think: Old information moves forward (pro-) and blocks the new.
• Example: You learned your old phone number so well that you keep writing it down instead of your new one.

B. Retroactive Interference (R.N.O.)

Recently learned information Now interferes with Old information.

• Think: New information moves backward (retro-) and blocks the old.
• Example: You learn Spanish this year, and now you struggle to recall the French you learned last year.

2. Cue-Dependent Forgetting (Retrieval Failure)

This theory suggests that forgetting is not due to the memory being gone, but because you lack the correct cue (a prompt or trigger) needed to access it. The memory is stored, but you can’t "find" the file.

This is often called the "Tip-of-the-Tongue" phenomenon. You know the information is there, but you can't quite pull it out.

Memory can be helped by using different types of cues:

A. Context-Dependent Cues

The external environment acts as a cue. If you learn something in one context (place), recalling it in the same context will be easier.
Example: You learn notes in the classroom, so taking the exam in that same classroom might improve your recall.

B. State-Dependent Cues

Your internal state (mood, emotions, level of alertness) acts as a cue. If you are in the same state when recalling information as you were when learning it, retrieval is easier.
Example: If you study while feeling calm, you might recall the information better when you are in a calm state during the exam.

Practical Tip: If you forget why you went into a room, walking back to the room you came from often provides the context cue you need!

🔑 Key Takeaway:

Forgetting happens because of Interference (memories clash) or Retrieval Failure (you don't have the right cue/prompt).

Summary Checklist for Memory