Learning
High-Yield Summary
- Learning = a change in behavior from experience, built from a stimulus (anything that can produce a response) and a response. Habituation = decreasing response to a repeated stimulus; dishabituation = responsiveness returning after something new happens.
- Classical conditioning (Pavlov) is stimulus-stimulus learning: a neutral stimulus paired repeatedly with an unconditioned stimulus (US) becomes a conditioned stimulus (CS) that alone triggers a conditioned response (CR), resembling the original unconditioned response (UR).
- Operant conditioning is behavior-consequence learning: reinforcement increases a behavior, punishment decreases it; positive = something added, negative = something removed — not good vs. bad.
- Reinforcement schedules combine ratio/interval (responses vs. time) with fixed/variable (predictable vs. unpredictable); variable ratio produces the highest, steadiest rate and is most resistant to extinction.
- Shaping reinforces successive approximations toward a complex final behavior.
- Latent learning, preparedness, and instinctive drift show cognitive/biological limits on simple conditioning — learning and performance aren't the same thing.
- Observational learning (Bandura's Bobo doll) happens by watching a model, and requires attention, retention, reproduction, and motivation (external, vicarious, or self).
Key Terms
- Unconditioned stimulus / response (US/UR)
- A stimulus that naturally produces a response with no learning required (e.g., food → salivation).
- Conditioned stimulus / response (CS/CR)
- A previously neutral stimulus that, after pairing with a US, gains the learned ability to produce a response.
- Reinforcement vs. punishment
- Reinforcement increases the likelihood a behavior repeats; punishment decreases it.
- Shaping
- Reinforcing successive approximations of a desired behavior until the full behavior is built.
- Latent learning
- Learning that occurs without reinforcement and isn't shown until there's a reason to demonstrate it (Tolman's cognitive map).
- Preparedness
- Biological predisposition to learn certain associations (e.g., fear of snakes) more easily than others.
- Instinctive drift
- A trained behavior is gradually overridden by an innate, species-specific behavior.
- Modeling
- Learning a behavior by observing and imitating a model, without direct conditioning.
Reinforcement vs. Punishment (Positive vs. Negative)
| Reinforcement — behavior increases | Punishment — behavior decreases |
|---|---|
| Positive: something desirable added (praise → more effort) | Positive: something aversive added (ticket → less speeding) |
| Negative: something aversive removed (medicine removes pain → repeat behavior) | Negative: something desirable removed (losing recess → less misbehavior) |
Interval vs. Ratio Reinforcement Schedules
| Interval (time-based) | Ratio (response-based) |
|---|---|
| Fixed interval: predictable time, scalloped pattern (pause after reward, speeds up before next) | Fixed ratio: predictable response count, high rate with a brief pause after each reinforcement |
| Variable interval: unpredictable time, steady moderate rate | Variable ratio: unpredictable response count, highest/steadiest rate, most resistant to extinction |
Classical Conditioning: Formation and Fate of an Association
- 1Before conditioning: an unconditioned stimulus (US, e.g. food) naturally produces an unconditioned response (UR, e.g. salivation); a neutral stimulus (e.g. bell) produces no response.
- 2Acquisition: the neutral stimulus is repeatedly paired with the US.
- 3After pairing, the neutral stimulus becomes a conditioned stimulus (CS) that alone produces a conditioned response (CR) resembling the UR.
- 4Extinction: presenting the CS repeatedly without the US causes the CR to gradually fade.
- 5Spontaneous recovery: after extinction and a rest period, the CR can suddenly reappear.
- 6Generalization: stimuli similar to the CS also trigger the CR. Discrimination: learning to respond only to the original CS, not similar ones.
Common MCAT Trap
- Negative reinforcement still increases behavior — it removes something unpleasant; it is not punishment.
- Ratio depends on number of responses, interval on time; fixed is predictable, variable is unpredictable — each of the four combinations has its own signature response pattern.
- Extinction is the CR fading out; spontaneous recovery is that same CR unexpectedly reappearing after a rest period.
- Generalization spreads the response to similar stimuli; discrimination narrows it back to only the original CS.
- Latent learning shows an organism can learn something without any immediate change in behavior — learning ≠ performance.
Quick Recall
A dog salivates to a bell it's never heard paired with food before, just because the bell sounds similar to its usual one. What's this called?
A rat is rewarded after an unpredictable number of lever presses. Which schedule, and what pattern of behavior?
What did Tolman's rat-maze experiment demonstrate?
What are Bandura's four requirements for observational learning?
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