Models of memory consolidation

what are the phases of episodic memory

1. short-term working memory

   1. prefrontal cortex stores information in working memory

2. short term memory and long-term memory

   1. from here, all memory requires physical storage

3. remote memory

   1. system consolidation

What are two major models of memory consolidation?

• Standard Consolidation Model (SCM)

• Multiple Trace Theory (MTT)

What is the Standard Model of memory consolidation?

Memories are initially stored in the hippocampus and gradually transferred to the neocortex, becoming hippocampus-independent.

Over time, memories become independent of the hippocampus as they are gradually transferred to neocortex for permanent storage.

What does the Multiple Trace Theory (MTT) propose?

The hippocampus is always involved in the retrieval of episodic memories, no matter how old the memory is; only semantic content can become hippocampally-independent.

describe the evidence for the standard model of memory consolidation

context fear memory (rats): rats shocked in a box, tested for freezing behaviour following a lesion on a later date

memory of short-lived pilot TV shows: people asked to recall details of TV shows that only aired for 1 season

medial temporal lobe damage: the later the damage to the medial temporal lobe, the less impact memory is

How do SCM and MTT differ in their predictions about hippocampal involvement over time?

SCM predicts decreased hippocampal involvement with memory age; MTT predicts continued hippocampal involvement for episodic recall, regardless of memory age.

what are evidence for MTT

context fear memory initially specific to the context where they were shocked, over time, fear generalizes to novel, unrelated contexts

episodic memory is forgotten, but semantic persists

How does sleep support memory consolidation?

Place cell activity is replayed in the hippocampus, especially CA3, during sleep, facilitating memory transfer and semantic abstraction.

What is memory reconsolidation?

A process where retrieved memories become labile (unstable) and must be re-stabilized, allowing them to be updated or altered.

What experiments support reconsolidation?

Contextual fear conditioning in rats and human studies using ECT show that reactivated memories can be disrupted or modified.

what is system reconsolidation

a process by which reactivated memories become temporarily unstable and are then restabilized — but potentially in a new brain system or with updated content.

What are the implications of memory reconsolidation for therapy?

Reconsolidation can be targeted to weaken traumatic memories, offering potential treatments for PTSD, phobias, and other memory-related conditions.

What happens if protein synthesis is blocked during reconsolidation?

The memory may be lost or weakened, showing reconsolidation depends on protein synthesis like initial consolidation.