Brain Substrates of Systems Consolidation

Consolidation of episodic memories over weeks to years across brian systems (hippocampus and other brain areas)

Systems Consolidation

What are the 2 types of Systems Consolidation?

1. Standard Model

2. Multiple Trace Model

Episodic memories are initially hippocampal-dependent and gradually become hippocampal-independent

Standard Model

Episodic memories are always hippocampal-dependent and gradually can become semantic memories

Multiple Trace Model

Which model requires the hippocampus for later memories?

Standard Model

Sometimes stronger for recent episodic memories compared to remote episodic memories

Temporally-Graded Retrograde Amnesia

In Temporally-Graded Retrograde Amnesia memories from adulthood to Injury are still _________ and have not undergone ________ yet so they are more sensitive to being lost.

hippocampal-dependent, systems consolidation

H.M had ________________ since his memories were impaired in recent years but not in remote years.

Temporally-Graded Retrograde Amnesia

Hippocampus is required only for the initial storage of an episodic memory

Standard Consolidation Theory

Hippocampal damage impairs retrieval of ______, but not ______, episodic memories in the Standard Consolidation Model

recent, remote

• Pairing a tone with a footshock in remote training within the Wilshire room

• 50 days pass by

• Pairing tone with a footshock in recent training within a different context, the sunset room

• Then, ½ the rats have a lesion of the hippocampus

• Rats are tested in the sunset room

According to the Standard Consolidation model rats who got lesions to their hippocampus did not remember freezing in the sunset room since it was the more _______ context

recent

Fear Conditioning, then tested 1 day (recent) or 1 month (remote) after conditioning

• Hippocampus inactivation during test

Resulted in which two effects?

1. Impaired recent memory

2. No effect on remote memory

Fear Conditioning, then tested 1 day (recent) or 1 month (remote) after conditioning

• Hippocampus inactivation during test

  1. Impaired recent memory

  2. No effect on remote memory

• Prefrontal Cortex Inactivation during test

Resulted in which two effects?

1. No effect on recent memory

2. Impaired remote memory

Some patients, such as V.C. with hippocampal damage show no temporal-grade to retrograde amnesia, instead loss of _____ and ______ memories

recent, remote

Overtime, some episodic memories can _______ and become semantic memories according to Multiple Trace Theory

lose detail

According to Multiple Trace Theory, with hippocampal damage _________ retrograde amnesia when a remote memory retains episodic detail.

complete

According to Multiple Trace Theory, with hippocampal damage ________ retrograde amnesia when a remote memory lacks details (e.g., about where, when)

temporally-graded