Introduction
Cognitive psychology studies mental processes: how we acquire, process, store, and use information. Unlike behaviorism which focused only on observable behavior, cognitive psychology examines the "black box" of the mind.
---
Perception
Our brain constructs our experience of reality-perception is not a passive recording of the world.
Bottom-Up vs Top-Down Processing
Bottom-up: Building perception from sensory input (data-driven).
Top-down: Using prior knowledge and expectations to interpret input (concept-driven).
Perception always involves both processes.
Gestalt Principles
Our brain organizes visual input using built-in rules:
- Proximity: Things close together are grouped
- Similarity: Similar things are grouped
- Continuity: We prefer smooth, continuous patterns
- Closure: We fill in missing parts to see complete shapes
- Figure-ground: We separate objects from background
These principles are automatic and largely universal.
Perceptual Illusions
Illusions reveal how our brain constructs reality:
The brain makes assumptions that usually work-illusions occur when these assumptions fail.
Change Blindness and Inattentional Blindness
We fail to notice large changes if they happen during a disruption (change blindness).
We fail to see unexpected objects when focused on something else (inattentional blindness).
---
Attention
Attention is the process of selecting what to focus on from the flood of sensory information.
Selective Attention
We can only consciously process a limited amount at once-attention acts as a filter.
Cocktail party effect: You can focus on one conversation in a noisy room, but your name in another conversation will "break through."
Divided Attention
Multitasking is mostly a myth-we rapidly switch between tasks rather than truly doing multiple things simultaneously.
Task switching has a cost-performance drops when switching between tasks.
Types of Attention
- Sustained attention: Maintaining focus over time (vigilance)
- Selective attention: Filtering out distractions
- Divided attention: Splitting focus between tasks
- Alternating attention: Switching between tasks
Attention and Performance
Arousal affects attention-moderate arousal is optimal (Yerkes-Dodson law).
Attention is limited and depletes over time-mental fatigue is real.
---
Memory Systems
Memory is not a single system but multiple systems with different functions.
Sensory Memory
- Holds sensory information very briefly (milliseconds to seconds)
- High capacity but rapid decay
- Iconic memory: Visual (lasts ~500ms)
- Echoic memory: Auditory (lasts ~3-4 seconds)
Working Memory (Short-Term Memory)
Function: Holds and manipulates information currently in use.
Baddeley's Model:
1. Phonological loop: Verbal/auditory information
2. Visuospatial sketchpad: Visual/spatial information
3. Central executive: Controls attention and coordinates subsystems
4. Episodic buffer: Integrates information from different sources
Capacity: About 4 items (not 7) without chunking.
Duration: Information decays within 20-30 seconds without rehearsal.
Long-Term Memory
### Explicit (Declarative) Memory
Consciously accessible:
Episodic memory: Personal experiences and events
- "What did you have for breakfast?"
- Tied to specific time and place
Semantic memory: General knowledge and facts
- "What is the capital of France?"
- Not tied to when you learned it
### Implicit (Non-Declarative) Memory
Not consciously accessible:
Procedural memory: Skills and how to do things
- Riding a bike, typing, playing piano
- Preserved in amnesia when explicit memory is lost
Priming: Previous exposure influences later processing
- Seeing "DOCTOR" makes recognizing "NURSE" faster
Classical conditioning: Learned associations
Memory Processes
### Encoding
Getting information into memory.
Deeper processing leads to better encoding-thinking about meaning works better than rote repetition.
Elaboration: Connecting new information to existing knowledge.
Organization: Structuring information meaningfully.
### Storage
Maintaining information over time.
Memories are not fixed recordings-they are reconstructed each time and can change.
Consolidation: Process of stabilizing memories over time.
Sleep is important for memory consolidation.
### Retrieval
Getting information out of memory.
Retrieval cues help access memories-same context aids recall.
Encoding specificity: Memory is best when retrieval context matches encoding context.
Testing effect: Retrieving information strengthens memory more than re-studying.
Memory Failures
### Forgetting
Most forgetting occurs soon after learning-the forgetting curve drops quickly then levels off.
Decay: Memories fade over time.
Interference:
- Proactive: Old memories interfere with new learning
- Retroactive: New memories interfere with old ones
### False Memories
Memories can be entirely fabricated-the brain fills in gaps with plausible information.
Eyewitness testimony is less reliable than commonly believed.
Leading questions can distort memory-"How fast was the car going when it smashed into the other car?" produces higher estimates than "hit."
---
Decision Making
Dual-Process Theory
System 1 (Fast thinking):
- Automatic, intuitive
- Effortless
- Prone to biases
- Good for familiar situations
System 2 (Slow thinking):
- Deliberate, analytical
- Effortful
- More accurate but slower
- Needed for complex problems
Most daily decisions use System 1-we only engage System 2 when necessary.
Heuristics
Mental shortcuts that usually work but can lead to errors:
### Availability Heuristic
We judge frequency/probability by how easily examples come to mind.
### Representativeness Heuristic
We judge probability by how well something matches a prototype.
### Anchoring
Initial information disproportionately influences judgment.
Biases in Decision Making
See [Psychology](/psychology) for more cognitive biases.
### Confirmation Bias
We seek and remember information confirming our beliefs.
### Overconfidence
People are typically overconfident in their judgments-especially in unfamiliar domains.
### Sunk Cost Fallacy
We continue investments based on past costs rather than future value.
### Framing Effects
How options are presented affects choices-"90% survival" sounds better than "10% mortality."
Improving Decisions
Consider the opposite-deliberately thinking about why you might be wrong reduces bias.
Use algorithms and checklists for important decisions-they often outperform intuition.
Seek diverse perspectives-others may see blind spots.
---
Problem Solving
Problem Types
Well-defined problems: Clear goal and solution path (math problems).
Ill-defined problems: Unclear goal or path (design problems).
Strategies
### Algorithms
Guaranteed to find solution if one exists, but may be slow.
### Heuristics
Mental shortcuts that often work:
Means-ends analysis: Reduce difference between current state and goal.
Working backward: Start from goal, work backward to current state.
Analogy: Apply solution from similar problem.
Obstacles to Problem Solving
### Fixation
We get stuck on one approach and fail to see alternatives.
Functional fixedness: We fail to see objects can be used in novel ways.
Mental set: Previous successful strategies prevent finding better solutions.
### Confirmation Bias in Problem Solving
We test hypotheses by seeking confirming evidence rather than trying to falsify.
Insight vs Analytical Problem Solving
Analytical: Gradual, step-by-step progress toward solution.
Insight: Sudden "aha!" moment where solution appears.
Insight often comes after incubation-setting the problem aside allows unconscious processing.
---
Metacognition
Metacognition: Thinking about thinking.
Monitoring
People are often poor at judging their own knowledge-illusions of competence are common.
Dunning-Kruger effect: Those least competent often overestimate their abilities most.
Control
Using metacognitive awareness to regulate learning:
- Allocating study time
- Choosing strategies
- Knowing when to seek help
Effective learners monitor and adjust their strategies.
---
---
See also: [Learning](/learning) for study strategies, [Psychology](/psychology) for cognitive biases, [Memory](/memory) for practical memory tips