Extinction

What were the two traditional assumptions about reinforcement and extinction?

The assumptions were (1) more reinforced trials produce stronger learning, and (2) resistance to extinction reflects associative strength.

In early runway experiments, how were rats with more training expected to behave during extinction?

They were expected to run faster and show slower extinction due to presumed stronger learning.

What is the Partial Reinforcement Extinction Effect (PREE)?

The effect where behavior reinforced only sometimes is more resistant to extinction than behavior reinforced every time.

Why is PREE surprising?

Animals with fewer reinforcements show more persistence, contradicting the idea that more reinforcement equals stronger learning.

What does PREE show about using extinction as a measure of learning?

Extinction is NOT a good measure of associative strength.

How does discrimination learning reveal true associative strength?

Animals with more reinforcement learn discriminations better, proving stronger learning even if they extinguish faster.

Why do partially reinforced animals extinguish more slowly according to the discrimination hypothesis?

They do not notice extinction has begun because they are used to nonreinforced trials.

What experiment tested the discrimination hypothesis?

Animals with partial reinforcement were later given extensive 100% reinforcement to make extinction easier to detect.

Did the discrimination test eliminate PREE?

No, partially reinforced animals still extinguished slowly.

What conclusion comes from the discrimination test?

Partial reinforcement teaches something deeper that persists beyond discrimination cues.

What is Amsel’s Frustration Theory?

The theory that nonreinforcement produces frustration, which becomes part of learning.

Why is frustration important in Amsel’s theory?

Frustration acts like a drive state that can be conditioned and can motivate behavior.

What evidence supports frustration as a response to nonreinforcement?

Pigeons expecting food during extinction often attack another pigeon, showing frustration.

What are the three properties of frustration?

(1) It induces drive, (2) it becomes conditioned, and (3) it serves as a discriminative cue (Sfrustration).

How does frustration become part of learning in partial reinforcement?

Animals learn that responding while frustrated sometimes leads to reinforcement.

How does frustration theory explain PREE?

Partially reinforced animals learn to respond in the presence of frustration, so they persist longer in extinction.

Why do 100% reinforced animals extinguish faster?

They never learned to respond under frustration, so frustration signals stopping.

What distinguishes short-term from long-term learning?

Short-term uses existing proteins; long-term requires protein synthesis and structural changes.

What is long-term potentiation (LTP)?

A synaptic strengthening process with early (protein-independent) and late (protein-dependent) phases.

How does Aplysia sensitization illustrate long-term learning?

Long-term sensitization produces new synaptic growth requiring protein synthesis.

What effect does anisomycin have on fear conditioning when given before learning?

It blocks long-term memory but not short-term memory.

What does the anisomycin effect show about memory?

Long-term memory requires protein synthesis, while short-term memory does not.

What is memory consolidation?

The process after learning where memories stabilize through protein synthesis.

How does electroconvulsive shock support consolidation?

It causes retrograde amnesia for recent memories, showing early memories are fragile.

What does anisomycin reveal about the consolidation window?

It disrupts memory only if given shortly after learning.

What role does the basolateral amygdala (BLA) play in fear conditioning?

It is required for long-term fear learning, and blocking protein synthesis there prevents long-term memory.

Why is extinction considered new learning?

Extinction forms a new memory that the CS is safe rather than erasing the original memory.

How does anisomycin affect extinction memory?

It prevents long-term extinction memory if given before or after extinction training.

Why does anisomycin not affect short-term extinction?

Short-term performance does not require protein synthesis.

When does anisomycin stop affecting extinction memory?

When given 6 hours after extinction training because consolidation is complete.

What is reconsolidation?

The process where reactivated memories become unstable and must be restabilized.

What experiment demonstrates reconsolidation?

A reminder CS followed by anisomycin disrupts long-term fear memory.

When does anisomycin disrupt reconsolidation?

Only if given immediately after the reminder cue.

Does anisomycin affect short-term memory after a reminder?

No, short-term memory remains intact.

What determines whether a CS-alone trial triggers extinction or reconsolidation?

The number of CS presentations and the strength of the original memory.

Which brain region's protein synthesis is required for reconsolidation?

The basolateral amygdala (BLA).