Questions: Memory Reconsolidation and Post-Retrieval Lability

Question 1

A protein synthesis inhibitor is injected into a rat's amygdala immediately after the rat retrieves a previously consolidated fear memory. What does reconsolidation theory predict?

• A. No effect — protein synthesis inhibitors only disrupt initial consolidation, not stored memories
• B. The fear memory will be impaired at subsequent testing — retrieval reopened a labile window
• C. The fear memory will be strengthened — reactivation triggers additional consolidation
• D. The inhibitor will prevent the rat from retrieving the memory again, but the original trace remains intact

Answer: (B)

The landmark Nader, Schafe & LeDoux (2000) finding is exactly this: injecting a protein synthesis inhibitor into the amygdala *after reactivation* impaired subsequent fear expression, as if the memory had been erased. The key is that retrieval destabilizes the stored memory, reopening a reconsolidation window that requires protein synthesis to re-stabilize. Without reactivation, the same inhibitor leaves the consolidated memory untouched — demonstrating that it's retrieval, not the passage of time, that creates lability.

Question 2

An eyewitness to a robbery is interviewed by a detective who asks, 'Did you notice the suspect's red jacket?' — even though the jacket was blue. Later, the witness reports the suspect wore a red jacket. Which mechanism best explains this?

• A. Encoding failure — the witness never properly encoded the jacket color during the event
• B. Source monitoring error — the witness confuses the detective's question with a separate memory
• C. Reconsolidation updating — the interview occurred during a retrieval-induced lability window, allowing misinformation to be incorporated into the restabilized memory
• D. Retrieval-induced forgetting — recalling other details suppressed the accurate jacket memory

Answer: (C)

When a memory is retrieved, it enters a labile state. If new information is present during that window, the restabilizing memory may incorporate it. The detective's question triggers retrieval of the robbery memory, which is then reconsolidated alongside the 'red jacket' suggestion — producing a memory that feels authentic but contains post-event misinformation. Source monitoring errors (option B) can also occur, but reconsolidation specifically explains why the *original* memory representation appears to change, not merely why the person confuses two separate memories.

Question 3

Once a memory has been reconsolidated after retrieval, it is permanently fixed and can seldom be modified by future retrievals.

• T. True
• F. False

Answer: False

Reconsolidation does not produce a final, immune-to-change state. Each new retrieval can again destabilize the memory and open another lability window. This means memories may be modified repeatedly across a lifetime of remembering — each time a memory is retrieved, it risks being updated by whatever information is present in that moment. The implication is that frequently recalled memories may drift furthest from their original form, because each retrieval is an opportunity for modification.

Question 4

Reconsolidation and initial consolidation are triggered by the same event: the encoding of new information.

• T. True
• F. False

Answer: False

Initial consolidation is triggered by *new learning* — it stabilizes a freshly formed memory trace. Reconsolidation is triggered by *retrieval of a previously consolidated memory* — it restabilizes a trace that was destabilized by reactivation. The triggers are fundamentally different: initial consolidation requires a new experience; reconsolidation requires reactivating an old one. This distinction is important because it means that simply recalling something — even without new learning — is the event that opens the modification window.

Question 5

Why might retrieval-extinction protocols (timing extinction trials to occur within the reconsolidation window) offer advantages over standard extinction therapy for fear memories?

Model answer: Standard extinction creates a new inhibitory memory that competes with the original fear trace but leaves it intact, which is why fear can return after extinction (spontaneous recovery, renewal, reinstatement). Retrieval-extinction times new learning to occur while the original fear memory is in a labile post-retrieval state, aiming to update the fear memory itself rather than just suppress it. If successful, the modified memory lacks the original fear content, reducing the substrate for relapse.

The therapeutic promise of reconsolidation is not just suppressing fear responses but potentially rewriting the fear memory at the level of its stored representation. Extinction therapy is limited because the original fear trace survives, and context changes can disinhibit it. Reconsolidation-based approaches aim at a more fundamental target: the memory content itself. The challenge is precisely timing interventions to the reconsolidation window in humans, where the window duration and conditions for opening it are less tractable than in animal models.