Introduction to Memory
Welcome to the study of Memory! This is one of the most exciting parts of Psychology because it explains how you learn, how you forget where you put your keys, and why your childhood memories feel so vivid. In this chapter, we will look at how memory is structured, why we sometimes forget things, and how reliable our memories actually are when we witness a crime. Don't worry if it seems like a lot to take in at first—we will break it down step-by-step!
Quick Tip: Think of memory not as a single "thing" in your brain, but as a process of saving and retrieving information, much like how a computer or a smartphone works.
1. The Multi-Store Model of Memory (MSM)
Proposed by Atkinson and Shiffrin, this model suggests that memory is made up of three separate stores. Information flows through these stores in a linear way.
Key Terms to Know
Before we look at the stores, we need to understand the three ways we measure them:
1. Coding: The "format" in which information is stored (e.g., as a sound or a picture).
2. Capacity: How much information the store can hold.
3. Duration: How long the information lasts in the store.
The Three Memory Stores
1. The Sensory Register (SR)
This is where information from your senses (sight, sound, smell) first arrives. It has a huge capacity but a very short duration (less than half a second). If you don't pay attention to it, the information is gone forever!
Example: Think of all the faces you see while walking through a crowded train station. You "see" them, but because you don't pay attention, you forget them instantly.
2. Short-Term Memory (STM)
If you pay attention to something, it moves to the STM.
- Coding: Mainly acoustic (sounds).
- Capacity: Limited. Research suggests it is \( 7 \pm 2 \) "chunks" of information.
- Duration: About 18 to 30 seconds.
Memory Trick: To keep info in STM longer, we use maintenance rehearsal (repeating it over and over in our heads).
3. Long-Term Memory (LTM)
If you rehearse information enough, it moves into LTM.
- Coding: Mainly semantic (meaning).
- Capacity: Potentially unlimited.
- Duration: Can last a lifetime.
Quick Review: Information enters the Sensory Register -> Attention moves it to STM -> Rehearsal moves it to LTM.
2. The Working Memory Model (WMM)
Proposed by Baddeley and Hitch, this model focuses only on the Short-Term Memory. They argued that STM isn't just one "waiting room" but a busy office with different people doing different jobs.
The Components of WMM
1. Central Executive
The "boss" of the office. It monitors incoming data and decides which "assistant" (the sub-systems) should deal with it. It has a very limited capacity.
2. Phonological Loop
This deals with auditory (sound) information. It is split into two parts:
- The Phonological Store: Your "Inner Ear" (holds the words you hear).
- The Articulatory Process: Your "Inner Voice" (allows for maintenance rehearsal—repeating words in a loop).
3. Visuo-Spatial Sketchpad
This is your "Inner Eye." It stores visual and spatial information (e.g., visualizing how many windows are in your house).
4. Episodic Buffer
Added later by Baddeley, this acts as a "bridge" between the other systems and Long-Term Memory. It combines information from the other stores into a single, coherent story.
Key Takeaway: The WMM explains how we can do two different tasks at once (like driving and talking) as long as they use different sub-systems!
3. Explanations for Forgetting
Why do we forget? Psychologists offer two main explanations: Interference and Retrieval Failure.
A. Interference
This happens when two pieces of information conflict with each other, resulting in forgetting or distortion. This usually happens when the memories are similar.
1. Proactive Interference: When an old memory interferes with a new one.
Example: You get a new phone number but keep telling people your old one.
2. Retroactive Interference: When a new memory interferes with an old one.
Example: You learn Spanish this year, and now you can't remember the French you learned last year.
Memory Aid (P.O.R.N):
Proactive = Old interferes with new.
Retroactive = New interferes with old.
B. Retrieval Failure (Cues)
This theory suggests the memory is still there, but you've lost the "key" to find it. These keys are called cues.
- Context-Dependent Forgetting: Forgetting because you are in a different place. (e.g., walking into a room and forgetting why you went there, then remembering when you go back to the kitchen).
- State-Dependent Forgetting: Forgetting because you are in a different internal state (e.g., learning something while you're caffeinated/excited and forgetting it when you are calm).
4. Eyewitness Testimony (EWT)
EWT is the evidence provided by people who witnessed a crime. Psychologists have found that EWT can be very unreliable due to several factors.
Factors Affecting Accuracy
1. Misleading Information
- Leading Questions: Questions that suggest a certain answer. For example, asking "How fast was the car going when it smashed into the other car?" vs. "How fast was the car going when it hit the other car?" (Loftus and Palmer).
- Post-Event Discussion: When witnesses talk to each other after an event, their memories can become contaminated or "mixed up" with what others said.
2. Anxiety
Does being scared help or hurt memory? It’s a bit of both!
- Low Anxiety: Accuracy is low (you aren't paying enough attention).
- Medium Anxiety: Accuracy is highest (you are alert).
- High Anxiety: Accuracy drops (you are too stressed or focused on the weapon—known as "Weapon Focus").
Improving EWT: The Cognitive Interview
Fisher and Geiselman developed a technique to help police get more accurate information using four steps:
1. Report Everything: Tell every single detail, even if it seems irrelevant.
2. Reinstate the Context: Imagine you are back at the scene (the weather, your feelings).
3. Reverse the Order: Describe the events backwards to prevent expectations or lying.
4. Change Perspective: Imagine the scene from the view of another witness.
Quick Review: Memory isn't a perfect video recording; it can be changed by the questions we are asked, the people we talk to, and how stressed we feel!
Don't worry if these models feel complex at first. The best way to learn them is to draw the diagrams for the MSM and WMM yourself and try to explain them to a friend!