PSYS 2100 (LCB)- Exam 1

What is the key difference between Pavlovian (classical) conditioning and operant (instrumental) conditioning?

Pavlovian Conditioning:

• Pairs two stimuli (CS–US) regardless of what the organism does

• Stimulus predicts outcome

• “Stimulus-outcome learning”

• “Respondent behavior”

• S predicts O, but S doesn’t cause O to occur

Operant conditioning:

• Changes behavior based on its consequences — behavior operates on the environment and is strengthened or weakened by reinforcement/punishment

• Response causes (produces or removes) outcome

• Lever press→food

What is the Unconditioned Stimulus (US)?

US: A stimulus that produces a natural response without conditioning

• Example: food eliciting salivation

What is the Conditioned Stimulus (CS)?

CS: A previously neutral stimulus that produces a learned/conditioned response (CR) after repeated pairing with a US

• Example: a bell paired with food comes to elicit salivation on its own

What distinguishes the Unconditioned Response (UR) from the Conditioned Response (CR)?

• UR: the innate, reflexive response to the US

  • Example: salivating to food

• CR: the learned response elicited by the CS after conditioning

  • Example: salivating to the bell

• The CR is often similar to the UR but not identical — it's frequently anticipatory/preparatory rather than a copy.

Why does Pavlovian conditioning engage a broad range of different conditioned responses rather than just one?

• The CS becomes a signal that prepares the whole organism for the upcoming US, physiologically and behaviorally

• A predictive cue triggers an integrated, functional behavior system and preparatory adaptation rather than a single isolated reflex

  • Example: a CS paired with shock produces freezing, heart rate changes, and hormonal changes together, a coordinated set of responses that get the animal ready for what's coming.

What is the operant–respondent distinction? How are they related to Pavlovian vs. instrumental conditioning?

Respondent behavior

• Elicited (called out) by a stimulus

• Reflexive

• Basis of Pavlovian conditioning

Operant behavior

• Emitted by the organism and controlled by its consequences

• Basis of instrumental conditioning

What is a reinforcer?

• Any stimulus or event that follows a response to increase the future frequency of that response

• Can work by adding something desirable or removing something aversive.

What is a cumulative record?

• A graph plotting total (cumulative) responses over time, developed by Skinner

• The pen steps up with each response, so the slope represents response rate

  • Flat = no responding

  • Steep = rapid responding

• It never resets, letting you see response patterns across a whole session.

What is positive reinforcement?

• Outcome is added, response increases

  • Example: a rat presses a lever and gets a food pellet, so lever pressing increases.

What is negative reinforcement, and what are its two subtypes?

• Outcome is remove/prevented, response increases

  • Escape: terminating an ongoing aversive stimulus

    • Example: pressing a lever turns off a shock

  • Avoidance: preventing the aversive stimulus from starting at all

    • Example: jumping a barrier before shock onset

What is positive punishment?

• Outcome is added, response decreases

  • Example: a shock follows a lever press, so pressing declines.

What is negative punishment (omission)?

• Outcome is removed, response decreases

• Called "omission" because a reinforcer is withheld following the response.

  • Example: taking away a phone for breaking curfew.

What is stimulus control? Define discriminative stimulus and SΔ (S-delta)?

Stimulus control: when the presence or absence of a stimulus determines whether an operant response occurs — the stimulus "controls" the behavior by signaling whether responding will pay off.

It comes from pairing:

• SD (discriminative stimulus) — the stimulus present when responding IS reinforced. It signals "respond now" and sets the occasion for the behavior.

• SΔ (S-delta) — the stimulus present when responding is NOT reinforced. It signals "don't bother responding."

Example: A pigeon is reinforced with grain for pecking a key only when a light is ON (SD), and pecking is never reinforced when the light is OFF (SΔ). After training, the pigeon pecks vigorously when the light is on and stops pecking when it's off — its pecking behavior is now under the stimulus control of the light.

What is stimulus generalization, and what does a generalization gradient show?

Generalization: responding to stimuli similar to the original CS or SD.

The gradient plots response strength against stimulus similarity: it peaks at the trained stimulus and tapers off as stimuli become less similar.

• Example: a pigeon trained to 550nm also pecks at 540nm and 560nm, but less.

How are pigeon categorization experiments conducted, and what do they show?

• Pigeons are reinforced for pecking at a yellow key and not reinforced for pecking at any other color of key

• They consistently peck at the yellow key for grain, they peck a bit at yellow-orange and yellow-green, and pecking decreases as the color gets more different from the yellow key

What is a conditioned compensatory response?

A learned response (CR) that is OPPOSITE in direction to the drug's actual effect, produced by the body in anticipation of the drug to counteract it.

• Example: morphine (US) decreases pain sensitivity (UR); cues signaling the drug (CS) come to elicit INCREASED pain sensitivity as the CR.

How does the conditioning of a compensatory response cause drug tolerance?

• Cues associated with drug administration become a CS that elicits a compensatory CR opposing the drug's effect, reducing net effect of drug and requiring more of the drug for the same effect

• Each repetition in the same context strengthens the compensatory response, deepening tolerance.

What evidence (Siegel) supports the hypothesis that morphine tolerance is due to a learned compensatory response, and how does this help explain drug abuse?

Rats given morphine repeatedly in the SAME context developed strong tolerance, but rats given the same drug history in a DIFFERENT context showed much less tolerance — responding as if more drug-sensitive. Tolerance is therefore tied to learned cues, not just pharmacology. This explains why drug-associated contexts trigger strong cravings and compensatory reactions in addicts.

What did research show about drug overdose in a context different from the usual injection context?

Rats given a previously well-tolerated high dose of heroin/morphine in a NOVEL room died at far higher rates than rats given it in their usual room. Without the familiar cues, the protective compensatory CR isn't triggered, so the full unopposed drug effect hits. This explains "unexpected" overdose deaths in experienced users who take their usual dose in an unusual setting.

Define extinction.

How is extinction produced in Pavlovian and operant conditioning, and what happens to the learned response?

Pavlovian: present the CS repeatedly WITHOUT the US. Operant: stop reinforcing the response. In both, the learned response gradually declines over trials. Critically, it weakens but is not erased.

What is the Partial Reinforcement Extinction Effect (PREE)? What are the two theories that explain it?

Responses trained with partial/intermittent reinforcement are MORE resistant to extinction than responses trained with continuous reinforcement. Think slot machines — intermittent payoffs make behavior harder to extinguish. The two explanations for it are frustration theory and generalization theory.

What is frustration theory's explanation of the PREE?

During partial reinforcement, the animal experiences frustration from non-reward during training itself and learns to keep responding through that frustration. Frustration becomes a cue that responding will eventually pay off, and this learned persistence carries over into extinction.

What is generalization theory's explanation of the PREE?

Extinction is more SIMILAR to partial-reinforcement training, since the animal already experienced many non-reinforced trials. So responding generalizes into extinction and persists. For continuously reinforced animals, extinction is a large, novel change they never experienced, so responding drops off fast.

What is spontaneous recovery?

The reappearance of an extinguished response after a period of time has passed since extinction, with no further training. Example: a rat's extinguished lever pressing partially returns after an overnight rest.

What is the renewal effect, and what are ABA, AAB, and ABC?

Renewal is the return of an extinguished response when the context changes. ABA = train in A, extinguish in B, test back in A. AAB = train and extinguish in A, test in new context B. ABC = train in A, extinguish in B, test in a brand-new context C. In all three, the response returns.

Why do spontaneous recovery and renewal show that extinction is NOT erasure?

The original response reappears — with time, or with a context change — without any new CS–US or response–reinforcer pairings. If extinction had erased the original learning, nothing would be left to reappear. Instead, extinction creates new, context-specific inhibitory learning that suppresses the original association without destroying it.

How does renewal explain relapse after Exposure Therapy?

Exposure therapy is extinction, usually conducted in the therapist's office (context B) while the fear was learned elsewhere (context A). When the patient meets the feared stimulus in a different context — the original one, or any new one — the fear renews. Extinction learning is context-specific, which is a major clinical challenge.

What technique reduces renewal after exposure therapy?

Conducting the extinction/exposure training across MULTIPLE different contexts rather than one fixed setting. Varying the environment keeps the new inhibitory learning from being tied to a single context, so it generalizes better to new situations.

What is the basic three-phase design of a blocking experiment, and what is the result?

Phase 1: CS-A alone paired with the US until A reliably predicts it. Phase 2: compound AB paired with the same US. Test: CS-B alone shows little or no conditioning — it was "blocked." Pairing a CS with a US is therefore NOT sufficient for conditioning; A already fully predicted the US, so there was nothing left for B to explain.

What is the design of an unblocking experiment, and what does it show?

Same as blocking, except the US is CHANGED in Phase 2 (e.g., made larger or more intense). This creates prediction error, and now CS-B DOES become conditioned. It shows that a surprising, unpredicted US is what drives new learning.

What are prediction error and US surprisingness, and what role do they play in classical conditioning?

Prediction error is the mismatch between the US expected (based on the CSs present) and the US that actually occurs. Learning is proportional to that discrepancy — this is the core of the Rescorla–Wagner model. No prediction error → no new learning (blocking). Large prediction error → learning resumes (unblocking).

What is "preparedness"?

The idea that organisms are biologically predisposed through evolution to learn certain associations more easily than others, especially survival-relevant ones. Not all CS–US pairings are equally learnable.

What experimental evidence with rats supports preparedness (Garcia & Koelling)?

Rats readily associated TASTE with later illness — even across long CS–US delays — but not with shock. They readily associated audiovisual cues with SHOCK but not with illness. Which pairings get learned depends on biological relevance, not just temporal contiguity. This is called selective association.

What is the evidence that preparedness is innate (present from birth)?

Very young, inexperienced animals with no prior taste–illness or cue–shock history show the same selective associations on their very first exposure. Since the bias appears before any experience could have taught it, it must be built in by evolutionary history rather than acquired.

What are Species-Specific Defense Reactions (SSDRs), and what is their role in avoidance learning?

SSDRs are innate, species-typical defensive behaviors that fire automatically in response to threat. Because they're so strong, avoidance learning is fast when the required response matches an SSDR (a rat easily learns to run or jump to avoid shock) and very difficult when it doesn't (a rat struggles to learn lever pressing to avoid shock, since pressing isn't a natural defense behavior).

What are examples of SSDRs in rats and in people?

Rats: freezing, fleeing/running, and fighting/biting. People: freezing, fleeing, fighting, plus automatic reactions like flinching and screaming. Broadly, the fight-flight-freeze repertoire.

How can preparedness explain failures of operant training procedures?

When a trained operant response conflicts with innate, prepared response tendencies, the instinctive behavior intrudes and takes over — called instinctive drift. The Brelands documented this: a raccoon trained to deposit a coin for food instead began rubbing and washing the coin like food, disrupting the trained response entirely.

What does research on whether eating is a response to need vs. anticipation of need show?

Eating is often triggered by learned anticipatory cues — time of day, meal-related cues — rather than by internal deficit signals alone. Animals and people frequently begin eating BEFORE any actual physiological need exists. Eating is anticipatory, not purely reactive to depleted energy stores.

What is cue-potentiated feeding, and what has research in animals and people shown?

Increased food consumption triggered by learned food-associated cues (sights, smells, sounds previously paired with food), even when the organism is already sated. Rats presented with a food-paired CS eat more despite being full; humans exposed to food cues like ads and smells likewise eat beyond satiety.

How does cue-potentiated feeding connect to overeating?

Food cues — packaging, smells, locations, advertisements, time of day — can trigger eating independent of physiological hunger. Modern environments are saturated with these cues, which promotes chronic overconsumption and contributes to obesity.

How do Pavlovian cues and instrumental behaviors relate to food consumption?

Through Pavlovian-to-Instrumental Transfer (PIT). A CS previously paired with food, presented while an animal is performing an operant response for food, increases the rate and vigor of that responding. Classically conditioned cues energize operant food-seeking even independent of current hunger state.