Psych Exam 2

Aquisition Graph

the period when the conditioned response becomes stronger through repeated pairings of the CS and US

Extinction

the process in which the conditioned response weakens and eventually disappears after the CS is presented without the US. This occurs due to built up INHIBITION (the dog is learning a NEW association: the bell no longer predicts food).

Spontaneous Recovery

is the re-emergence of a conditioned response after a period of rest, following extinction. This phenomenon suggests that the learned behavior is not completely forgotten. (WHY— some of the inhibition dissipated (weakened) during the rest period). However, if the researcher continues ringing the bell without food, the dog stops salivating again — and extinction happens faster this time.

Habituation vs. Extinction

Extinction involves unlearning or inhibiting an association that was previously formed. Habituation involves no prior conditioning or association between two stimuli; the nervous system simply tunes out constant or repetitive background noise, sights, or feelings.

Excitation vs. Inhibition

During extinction, inhibition builds until it cancels excitation. During a rest period, inhibition partially dissipates, allowing the CR to reappear.

What is this graph showing?

The graph is showing that extinction doesn't necessarily erase the original learning.

First spontaneous recovery

CR RETURNS — After a 24-hour rest, inhibition partially dissipates. Salivation returns, but not as strongly as before. With more unreinforced trials, it disappears faster.

Second spontaneous recovery

WEAKER CR RETURN — After another 24-hour rest, the CR returns at an even lower strength because more inhibition remains.

Contiguity

closeness in TIME. The CS and US must occur sufficiently close together for effective conditioning.

Example:

• Bell rings → Food appears 2 seconds later: association can form.

• Bell rings → Food appears 1 hour later: association is much harder to form.

Optimal Time Interval

the BEST timing.

Conditioned response	Optimal CS–US interval
Dog salivation	0.5–30 seconds
Human eye blink	0.5 seconds

Optimal interval depends on the particular response being conditioned. The number of trials needed also varies.

Contiguity vs. the Optimal Time Interval

Contiguity describes how close the stimuli occur in time; optimal time interval describes the timing that produces the strongest conditioning.

More intense CS (e.g. a louder conditioned tone) can produce….

A stronger CR (e.g. more salivation)

This connects directly to amplitude, which measures the strength of the conditioned response.

What is this graph showing?

the amount of time between presenting the conditioned stimulus (CS) and unconditioned stimulus (US) affects how successfully conditioning occurs.

optimum of approximately 0.5 seconds for the response studied—not necessarily for every type of conditioning.

Higher-order Conditioning

This is when a stimulus that has already become a CS is used to condition a NEW stimulus, without presenting the original US during the second stage.

Bell (CR) + New tone —> present together WITHOUT food (US) —> eventually, New Tone produces salivation (CR)

(*** Bell acts like a US because it can now help condition the new tone.)

Generalization

“CLOSE ENOUGH” The new tone is similar enough to the original CS that it triggers the same conditioned response!

(a new stimulus produces the CR because it resembles the original CS, without needing additional pairing.)

Discrimination

telling stimuli APART

Example:

• CS+ (high tone): Paired with food → dog salivates.

• CS− (low tone): Never paired with food → dog learns not to salivate.

Eventually, the dog responds to the high tone but not the low tone.

What is this graph showing?

Second-ordering conditioning.

What is this graph showing?

Generalization gradient: How similarity between stimuli affects the strength of a conditioned response.

(how often an animal produces a conditioned response when presented with tones of different frequencies)

—> The highest point of the graph represents the stimulus producing the strongest response. As the test stimulus becomes less similar, responding generally decreases.

CR isn’t always the same as the UR

the CR can be a preparatory response that helps the organism anticipate the upcoming US.

(Forward & Backward Conditioning)

Forward Conditioning

CS before US → usually effective

Backward Conditioning

US before CS → generally ineffective for establishing an excitatory CR, as emphasized in your lecture.

Pavlov's view

CS-CR conditioned reflex

The Modern View

A CS–US association in which the CS predicts the US.

Basically, it emphasizes that Classical conditioning is not always:

CS → CR that copies the UR

Instead, the modern view emphasizes:

CS → Predicts US → Body produces an anticipatory response

The CR might resemble the UR, differ from it, or oppose it.

Preparatory

getting ready for something that's about to happen.

(Instead of simply copying the body's natural reaction to a stimulus, the conditioned response can help the body prepare for the stimulus it expects to receive.)

MORPHINE EXAMPLE PREDICTING AN PREPARATORY RESPONSE

Imagine someone repeatedly receives morphine in a medical setting.

Step 1: The body's natural response

Morphine (US) → Less pain sensitivity (UR).

Step 2: The body learns an association

Cues associated with receiving the medication, such as an injection-related cue, become a CS.

Step 3: The body prepares

Eventually, the injection-related cue alone can trigger increased pain sensitivity (CR).

—> in this example, the CR is the OPPOSITE of the UR

Simultaneous pairing

CS and US begin TOGETHER

backward conditioning generally…

FAILS. This supports the modern view that the CS must provide useful information about the upcoming US.

trial and error; incremental learning

Cat placed in box accidentally presses a lever to escape and get to food. The more times the cat gets placed in the box, the quicker each time it figure out to press the lever to escape.

—> its behavior improves over repeated trials as successful responses become more likely.

Thorndike's Law of Effect

Behaviors followed by satisfying consequences become more likely, while behaviors followed by unpleasant consequences become less likely.

Consequence	Effect on future behavior
Reinforcement (satisfying outcome)	Behavior increases ↑
Punishment (unpleasant outcome)	Behavior decreases ↓

For example, a cat accidentally presses a lever and escapes its puzzle box.

Because escaping is satisfying, the cat becomes more likely to press that lever again.

This is the foundation of operant conditioning: We learn from the consequences of our actions.

—> response is automatically strengthened when
followed by reinforcement ("satisfying state of affairs");
automatically weakened when followed by punishment
("annoying state of affairs")

Classical Conditioning

Learning associations between stimuli

Often involves involuntary responses

Pavlov's dog salivates to a tone

Operant Conditioning

Learning associations between behavior and consequences

Often involves voluntary actions

Thorndike's cat learns to escape a box

What is this graph showing?

Thorndike's trial-and-error learning

Classical Conditioning

Produces a SIGNAL. The response is elicited (triggered) & involuntary. CS—US Association (contiguity).

e.g. Dog salivates to bell

Operant Conditioning

Produces a BEHAVIOR & its consequences. The response is emitted (performed) & voluntary. The reinforcement depends on the response (contingency). Law of Effect / consequences.

e.g. Rat presses lever for food.

Elicited

Triggered by a stimulus.

e.g. A dog hears a bell and automatically salivates.

The bell triggers the learned response. The dog doesn't deliberately choose to salivate.

Emitted

Performed by the organism.

e.g. A rat presses a lever and receives food.

The rat performs an action, and the consequence determines whether it will repeat that action.

Classical

The stimulus predicts another stimulus

Operant

The behavior produces a consequence.

Delayed reinforcement weakens…

the response.

Thorndike

Operant Conditioning — cats in a puzzle box

B.F Skinner

Operant Conditioning — Skinner Box Rat / Lever Experiment

Response Rate (Dependent Variable)

measures how frequently an animal performs a behavior over a given period

Example: A rat presses a lever 30 times in 5 minutes.

Response Rate = 30/5 = 6 presses/minute

Independent variable (IV)

Reinforcement conditions manipulated by the researcher.

Positive

ADD something.

Negative

REMOVE something.

Reinforcement

Always INCREASES behavior.

Punishment

Always DECREASES behavior.

Positive Reinforcement

Add, Increase

Example:

You study and receive praise, so you study more often.

Negative Reinforcement

Remove, Increase.

Example:

You buckle your seat belt and the annoying alarm stops, so you buckle up more promptly.

Positive Punishment

Add, Decrease.

Example:

You talk during lecture and receive a reprimand, so you talk less.

Negative Punishment

Remove, Decrease.

Example:

You repeatedly break a dorm rule and lose a privilege, so you break the rule less often.

Appetitive stimulus

Something desirable, such as food or approval.

(Positive Reinforcement delivers an appetitive stimulus)

Aversive stimulus

Something unpleasant, such as an annoying alarm.

(Negative Reinforcement delivers an aversive stimulus)

stimulus generalization

Imagine a pigeon has learned to peck a key when a yellow light is on because pecking produces food.

The researcher then presents other colored lights.

The pigeon may also peck when it sees orange, green, red, or blue lights.

However, the pigeon responds most frequently to yellow.

Why? The other colors share some similarity with the original stimulus.

Classical generalization

Measure conditioned response

Operant generalization

Measure response rate

Discriminative stimulus (SD)

A stimulus that indicates under what circumstances a response will be reinforced.

Example:

Light on —→ Rat Presses Lever —→ Food Delivered

Light = Discriminative stimulus because it tells the rat WHEN pressing the lever is likely to work.

"Stimulus does NOT cause response, or SIGNAL reinforcement; it SETS OCCASION for response."

Conditioned (Secondary) Reinforcer

How something becomes rewarding through learning.

Example: A clicker and food

Something that wasn't originally rewarding becomes rewarding because it gets associated with something that already is.

Partial Reinforcement Effect

Why reinforcing a behavior only sometimes can make it harder to extinguish. Reinforcing only SOME trials can produce a stronger resistance to extinction than reinforcing ALL trials.

EXAMPLE—

Imagine two rats:

Rat A: Gets food every single time it presses a lever.

Rat B: Gets food only occasionally.

Now the researcher stops giving food to both rats.

• Rat A is accustomed to getting food every time. When food stops, its lever pressing tends to decline relatively quickly.

• Rat B is already accustomed to pressing without always receiving food. It may continue pressing much longer before its behavior declines.

Schedules of Reinforcement (4 TERMS)

Fixed Ratio — Set number of responses (e.g. Reward after every 5 lever presses)

Variable Ratio — Changing number of responses (e.g. Reward after an unpredictable number of presses)

Fixed Interval — Set amount of time (e.g. First response after every 30 seconds is reinforced)

Variable interval (VI) — Changing amount of time (e.g. First response after unpredictable time intervals is reinforced)

EASY MEMORIZATION:

• Ratio = Responses (how many times?)

• Interval = Time (how long?)

• Fixed = Predictable

• Variable = Unpredictable

Tricky Distinguishing

Conditioned stimulus (CS)	"Something is COMING!"
Discriminative stimulus (SD)	"NOW is your chance to earn something!"
Conditioned reinforcer	"I learned that this is REWARDING!"