Cognitive Psychology Experiments

Why This Matters

Cognitive psychology experiments aren't just historical footnotes—they're the foundation for everything you'll encounter in cognitive science. These studies reveal the mechanisms behind attention, memory encoding, learning, and social behavior, and they show up repeatedly on exams because they demonstrate core principles in action. When you understand why Sperling used partial report or what made Milgram's participants obey, you're grasping the architecture of the mind itself.

You're being tested on your ability to connect experimental methods to theoretical frameworks. Don't just memorize that Pavlov rang a bell—know that his work demonstrates associative learning and the difference between conditioned and unconditioned stimuli. Each experiment on this list illustrates a specific cognitive mechanism, and your job is to identify which principle each one proves. Master the "why" behind the "what," and you'll handle any comparison question thrown your way.

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Attention and Cognitive Control

These experiments reveal how the brain manages competing information and why some processes override others. Automatic processing happens without conscious effort, while controlled processing requires deliberate attention—and when they conflict, fascinating things happen.

Stroop Effect Experiment

• Automatic vs. controlled processing conflict—participants struggle to name ink colors when the word spells a different color (e.g., "RED" printed in blue), because reading is automatic and overrides color naming
• Processing speed differences explain the interference; reading develops earlier and becomes more practiced than color identification, making it harder to suppress
• Cognitive flexibility is measured by how well participants can inhibit the automatic reading response—a key indicator of executive function

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Memory Systems and Encoding

Memory isn't a single system—it's a collection of specialized processes with different capacities and durations. These experiments map out sensory memory, working memory, and long-term memory, showing how information moves between them.

Sperling's Iconic Memory Experiment

• Iconic memory holds visual information for roughly 250-500 milliseconds with high capacity but rapid decay
• Partial report technique—cueing participants to recall only one row of a briefly flashed letter grid—proved that sensory memory stores more than we can report before it fades
• Sensory processing bottleneck explains why we can't transfer everything to working memory; this experiment defined the boundary between sensation and cognition

Baddeley's Working Memory Model Experiments

• Multi-component architecture—the model includes the phonological loop (verbal information), visuospatial sketchpad (spatial/visual information), and central executive (attention control)
• Dual-task paradigms showed that verbal and spatial tasks interfere with their respective subsystems but not with each other, proving separate storage mechanisms
• Cognitive load theory emerged from this work, explaining why overloading one component degrades performance on related tasks

Ebbinghaus Forgetting Curve Experiment

• Exponential memory decay—Ebbinghaus demonstrated that forgetting is steepest immediately after learning, then levels off over time
• Nonsense syllables (like "DAX" or "BUP") eliminated meaning-based associations, isolating pure retention from semantic memory effects
• Spacing effect discovery showed that distributed practice produces stronger retention than massed practice—a principle still used in study strategies today

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Memory Reconstruction and Reliability

Memory isn't a video recording—it's a reconstructive process vulnerable to distortion. These experiments demonstrate how post-event information and suggestive questioning can alter what we think we remember.

Loftus and Palmer's Car Crash Experiment

• Misinformation effect—changing a single verb ("smashed" vs. "contacted") in a question altered participants' speed estimates and even created false memories of broken glass
• Schema-driven reconstruction explains the mechanism; our brains fill in gaps using expectations, making memory malleable rather than fixed
• Eyewitness testimony implications are profound—this research transformed legal understanding of witness reliability and interrogation practices

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Learning Mechanisms

How do organisms acquire new behaviors? These foundational experiments established the two major learning paradigms: classical conditioning (learning through association) and operant conditioning (learning through consequences).

Pavlov's Classical Conditioning Experiments

• Associative learning—pairing a neutral stimulus (bell) with an unconditioned stimulus (food) creates a conditioned response (salivation to the bell alone)
• Key terminology: the unconditioned stimulus (US) naturally triggers a response; the conditioned stimulus (CS) only triggers it after learning; extinction occurs when the CS is repeatedly presented without the US
• Stimulus generalization and discrimination—organisms respond to similar stimuli (generalization) but can learn to distinguish between them (discrimination)

Skinner's Operant Conditioning Experiments

• Behavior shaped by consequences—the Skinner box demonstrated that animals increase behaviors followed by reinforcement and decrease behaviors followed by punishment
• Reinforcement schedules (fixed-ratio, variable-ratio, fixed-interval, variable-interval) produce different response patterns; variable-ratio schedules create the most persistent behavior
• Positive vs. negative reinforcement—positive adds a pleasant stimulus; negative removes an unpleasant one; both increase the target behavior (don't confuse negative reinforcement with punishment)

Bandura's Bobo Doll Experiment

• Observational learning—children who watched adults behave aggressively toward a Bobo doll later imitated that aggression, even without direct reinforcement
• Modeling demonstrates that learning can occur without personal experience; we acquire behaviors by watching others and noting consequences they receive (vicarious reinforcement)
• Social learning theory bridges behaviorism and cognitivism, showing that internal cognitive processes mediate between stimulus and response

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Social Influence and Authority

These controversial experiments reveal how powerfully situations shape behavior—sometimes overriding personal values and moral judgment. They demonstrate obedience, conformity, and role adoption under social pressure.

Milgram Obedience Experiment

• Obedience to authority—65% of participants administered what they believed were dangerous (450-volt) shocks to another person when instructed by an authority figure in a lab coat
• Situational factors dramatically affected obedience rates: proximity to the "victim," presence of dissenting confederates, and legitimacy of the authority figure all modulated compliance
• Agentic state theory—Milgram proposed that people shift responsibility to authority figures, suspending personal moral judgment when following orders

Stanford Prison Experiment

• Role adoption and situational power—participants randomly assigned as "guards" quickly adopted authoritarian behaviors, while "prisoners" became passive and distressed
• Deindividuation occurred as uniforms and roles replaced individual identity, demonstrating how context can override personality
• Ethical concerns led to early termination after six days; the study now serves as a case study in research ethics as much as social psychology

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Quick Reference Table

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Self-Check Questions

1. Both Pavlov's and Skinner's experiments involve learning, but they differ in a fundamental way. What type of response does each study, and why does this distinction matter for understanding behavior modification?

2. If an FRQ asks you to explain why eyewitness testimony is unreliable, which experiment provides the strongest evidence, and what specific mechanism does it demonstrate?

3. Compare Sperling's iconic memory experiment with Baddeley's working memory model. How do they address different stages of memory processing, and what methods did each use to isolate their target system?

4. The Milgram and Stanford Prison experiments both reveal the power of situations over individual behavior. What is the key difference in how social influence operated in each study?

5. A student claims that Bandura's Bobo Doll experiment proves the same thing as Skinner's operant conditioning research. How would you explain why this is incorrect, and what unique contribution does Bandura's work make to learning theory?