# Cognitive Psychology
Cognitive Psychology is the scientific study of mental processes including attention, memory, perception, language, problem-solving, and decision-making. Emerging in the 1950s-60s as a reaction to behaviorism, it treats the mind as an information-processing system that can be studied through rigorous experimentation. The "cognitive revolution" was influenced by information theory, linguistics ([[Noam Chomsky]]), and early computer science.
Cognitive psychology profoundly influenced [[Human-Computer Interaction (HCI)]] and [[User Experience (UX)]] design. Understanding how humans perceive, remember, and process information enables designers to create more effective interfaces. Key figures include [[George Miller]] (working memory limits), [[Herbert Simon]] and [[Allen Newell]] (problem-solving), [[Daniel Kahneman]] (heuristics and biases), and [[Ulric Neisser]] (coined "cognitive psychology").
## Core Topics
| Topic | Description |
|-------|-------------|
| **Attention** | Selective focus, divided attention, attention limits |
| **Perception** | How we interpret sensory information |
| **Memory** | Encoding, storage, retrieval of information |
| **Language** | Comprehension, production, acquisition |
| **Problem Solving** | Strategies for achieving goals |
| **Decision Making** | How choices are made |
| **Learning** | Acquiring new knowledge and skills |
| **Reasoning** | Logical and inferential thinking |
## Memory Systems
```
┌─────────────────────────────────────────────────────┐
│ Sensory Memory │
│ (milliseconds to seconds) │
└──────────────────────┬──────────────────────────────┘
▼ Attention
┌─────────────────────────────────────────────────────┐
│ Working Memory (Short-term) │
│ 7±2 items, ~20 seconds without rehearsal │
└──────────────────────┬──────────────────────────────┘
▼ Encoding
┌─────────────────────────────────────────────────────┐
│ Long-term Memory │
│ ┌─────────────────┐ ┌─────────────────────────┐ │
│ │ Declarative │ │ Procedural │ │
│ │ (facts, events) │ │ (skills, habits) │ │
│ └─────────────────┘ └─────────────────────────┘ │
└─────────────────────────────────────────────────────┘
```
## Key Principles for Design
| Principle | Implication |
|-----------|-------------|
| **Miller's Law** | ~7 items in working memory → chunk information |
| **Attention is limited** | Reduce cognitive load, guide focus |
| **Recognition > Recall** | Show options rather than require memory |
| **Chunking** | Group related items to aid memory |
| **Mental models** | Users have expectations; match them |
| **Cognitive load** | Minimize unnecessary mental effort |
## Key Figures
| Person | Contribution |
| ------------------- | ---------------------------------------------- |
| [[Ulric Neisser]] | Coined "cognitive psychology" (1967) |
| [[George Miller]] | Working memory limits ("magical number seven") |
| [[Herbert Simon]] | Problem-solving, bounded rationality |
| [[Allen Newell]] | Cognitive architectures, AI |
| [[Daniel Kahneman]] | Heuristics, biases, dual-process theory |
| [[Amos Tversky]] | Decision-making, prospect theory |
| [[Noam Chomsky]] | Language acquisition, critique of behaviorism |
## Cognitive Psychology in HCI
Cognitive psychology informs interface design:
- **[[GOMS Model]]**: Predict task performance times
- **[[Usability]] heuristics**: Based on cognitive principles
- **[[Information Architecture (IA)]]**: Match mental models
- **Error prevention**: Understand how mistakes happen
- **[[Learnability]]**: How users acquire skills
## History
- **1950s**: Cognitive revolution begins
- **1956**: Dartmouth AI conference; Miller's "Magical Number Seven"
- **1967**: Neisser's *Cognitive Psychology* published
- **1983**: Card, Moran, Newell's *Psychology of HCI*
- **2002**: Kahneman wins Nobel Prize for behavioral economics
## References
- https://en.wikipedia.org/wiki/Cognitive_psychology
- https://www.apa.org/topics/cognitive-psychology
- Miller, G. (1956). "The Magical Number Seven, Plus or Minus Two"
## Related
- [[Human-Computer Interaction (HCI)]]
- [[Herbert Simon]]
- [[Allen Newell]]
- [[GOMS Model]]
- [[Usability]]
- [[User Experience (UX)]]
- [[Daniel Kahneman]]
- [[Attention]]