Atlas MCAT Course
Psychological & Social Foundations → Learning & Memory
Learning & Memory
How experience changes the system.
01The idea
Learning is not “adding information.” It is changing how a system responds to input.
This definition matters because it excludes temporary states (fatigue, drugs) and includes both behavior and internal representations.
THREAD · Regulation vs. capacity
02Build the model
ATwo grand classes of learning
| Associative learning | Non-associative learning |
|---|---|
| Learning relationships between events | Learning about a single stimulus |
| Classical conditioning: associating two stimuli | Habituation: decreased response with repetition |
| Operant conditioning: associating actions with consequences | Sensitization: increased response after strong stimulation |
BClassical conditioning: predictive associations
Classical conditioning is about prediction, not reward. Key elements: neutral stimulus (NS), unconditioned stimulus (US), unconditioned response (UR), conditioned stimulus (CS), and conditioned response (CR).
CGeneralization, discrimination, extinction
In generalization, similar stimuli evoke the response. In discrimination, the response occurs only to the specific stimulus. In extinction, the response weakens when the prediction fails.
DOperant conditioning: consequences shape behavior
Operant conditioning focuses on actions. Behavior is shaped by reinforcement (which increases behavior) and punishment (which decreases behavior). Direction — positive or negative — refers to adding or removing something, not “good” vs “bad”.
| Effect | Add (positive) | Remove (negative) |
|---|---|---|
| Behavior increases | Positive reinforcement | Negative reinforcement |
| Behavior decreases | Positive punishment | Negative punishment |
EReinforcement schedules: timing matters
| Schedule | Behavior pattern |
|---|---|
| Fixed ratio | Predictable bursts |
| Variable ratio | Steady, resistant to extinction |
| Fixed interval | Scalloped response |
| Variable interval | Steady, moderate |
FCognitive learning: beyond conditioning
Not all learning is stimulus–response. Latent learning is knowledge without reinforcement; observational learning is learning by watching others; insight learning is sudden problem restructuring. These emphasize internal representations.
GMemory: storage across time
Memory is organized by time scale and function.
HLong-term memory subtypes
| Explicit (declarative) | Implicit (non-declarative) |
|---|---|
| Semantic: facts | Procedural: skills; priming: prior exposure effects |
| Episodic: events | Conditioning: learned associations |
IEncoding, storage, retrieval
Memory formation involves encoding (transforming input), storage (maintaining the representation), and retrieval (accessing stored information). Failure can occur at any stage.
JBiological basis: plasticity
At the neural level, learning reflects synaptic strength changes, circuit reweighting, and structural modification. Long-term potentiation (LTP) — an increased synaptic response after repeated activation — is a leading cellular model for learning.
KForgetting: loss or inaccessibility
Forgetting can arise from decay (trace weakening), interference (competing memories), or retrieval failure (an access problem, not loss). Context often matters more than time.
LMemory is reconstructive
Recall is not playback. It is reconstruction. This explains false memories, bias, and suggestibility.
03See the connections
The lesson names these links itself. Read the map left to right.
Learning
- Classical (predict)
- Operant (consequences)
- Non-associative
- Cognitive (latent, observational)
Memory
- Sensory → working → long-term
- Explicit vs implicit
Mechanism
- Plasticity, LTP
- Reconstruction at recall
Next: cognition and decision-making.
04Reason with it
Four questions. Answer in your head first, then choose. You’ll see the reasoning either way.
Think first.
A child learns to fear the sound of a dentist’s drill after painful visits, without any reward involved. What kind of learning is this?
Think first.
A rat learns a maze while exploring with no reward, then runs it perfectly once food is added. What does this show?
Think first.
Which schedule produces behavior most resistant to extinction?
Think first.
A patient with amnesia can’t recall learning to ride a bike last month but rides it well. Which memory is preserved?
05MCAT lens
Predict the pattern
Learned fear without reward → classical conditioning
Behavior shaped by consequences → operant conditioning
Knowledge without reinforcement → latent learning
Skill learning preserved despite amnesia → procedural memory
06Common traps
Trap 1: Negative reinforcement is punishment
Misconception
“Negative” means removing something.
Correct model
Reinforcement increases behavior; punishment decreases it.
Trap 2: Extinction erases the original learning
Misconception
Extinction is new learning.
Correct model
The original association can return.
Trap 3: Memory is a recording played back
Misconception
Recall is reconstruction.
Correct model
Memory reflects current understanding as much as past input.
07Dependency check
Can you reconstruct this concept without looking at the page? You should now be able to reason through:
How learning differs by mechanism
Check against 02 · A through F.
Why reinforcement timing matters
Check against 02 · E: schedules.
How memory systems are organized
Check against 02 · G and H: time scale and type.
Why recall is imperfect
Check against 02 · K and L: forgetting and reconstruction.
If something feels unclear, the missing idea is usually thisLearning changes system behavior; memory preserves those changes across time.
08Remember
REMEMBER · if you keep only a few things
- Learning = durable change from experience.
- Classical: stimulus predicts stimulus. Operant: action → consequence.
- Positive/negative = add/remove, not good/bad.
- Variable ratio is most extinction-resistant.
- Explicit (semantic, episodic) vs implicit (procedural, priming, conditioning).
- Recall is reconstruction.
09Forward hook
With learning and memory in place, we move to higher-order processing.
How does the mind select, interpret, and choose right now?
That leads to cognition and decision-making.
Next lessonCognition & Decision-Making→