Cognitive Neuroscience Lecture 27: Hippocampus/MTL, Binding, & Consolidation

What is the role of the hippocampus/medial temporal lobe (MTL) in memory?

They are ideally situated to bind together item and context information, supporting episodic memory.

What two brain areas contribute to input for memory binding in the MTL?

The perirhinal cortex (PRC) and the parahippocampal cortex (PHC).

What does the perirhinal cortex (PRC) process?

Item-related information (the "what").

What does the parahippocampal cortex (PHC) process?

Context-related information (the "where" and "when").

Does forgetting always mean the memory is lost?

No; better context or retrieval cues can help recover the memory.

What are the two main processes involved in recognition memory?

Familiarity and recollection.

What is familiarity in memory?

A feeling of knowing something without recalling specific details or context.

What is recollection in memory?

The retrieval of specific event details or contextual information.

Example of familiarity without recollection

Recognizing an actor's face but not remembering their name or the movie they were in

Which brain region is associated with item-specific information and familiarity?

The perirhinal cortex (PRC).

Which brain region is associated with contextual information and recollection?

The hippocampus; binding of item and context.

What is the role of the parahippocampal cortex (PHC)?

Processing context-related input, such as spatial or environmental cues.

Simplified model of medial temporal lobe (MTL) function?

PRC → item-specific info → familiarity

Hippocampus → binding of item-in-context → recollection

What is the difference between familiarity and recollection?

Familiarity: a sense of knowing without specific details

Recollection: retrieving the original episodic context and details

How is perirhinal cortex activity related to recognition confidence?

It increases as recognition confidence increases.

What happens when binding is unsuccessful during encoding?

Later retrieval will only produce item-specific familiarity, not full episodic recollection.

What does successful hippocampal encoding predict?

Recollection of the item with contextual details.

Which memory stages are supported by the hippocampus/MTL?

Encoding, consolidation, and retrieval.

What type of information is processed by the perirhinal cortex (PRC-LEA)?

Item-related information (the "what").

What type of information is processed by the parahippocampal cortex (PHC-MEA)?

Contextual information (the "where").

What happens to item and context information in the hippocampus?

The hippocampus binds item and context together to form an integrated episodic memory (item-in-context).

What are the two types of consolidation in the brain?

Synaptic consolidation and systems consolidation.

Where does synaptic consolidation occur?

Throughout the brain, at the level of individual synapses.

What is systems consolidation?

A slower process by which encoded memories become stable and long-lasting through reorganization of brain circuits.

What is synaptic consolidation?

A rapid process that increases communication efficiency at synapses, often through long-term potentiation (LTP).

What brain region is central to systems consolidation?

The hippocampus and medial temporal lobe (MTL).

What does systems consolidation involve over time?

The gradual transfer and integration of memories from the hippocampus to distributed neocortical areas.

What does the Standard Consolidation Theory (SCT) propose?

The hippocampus has a time-limited role in declarative memory; over time, memories become independent of the hippocampus and are stored in the cortex.

What does the Trace Transformation Theory (TTT) propose?

The hippocampus's role depends on the nature of the memory, not just its age.

What theory did Trace Transformation Theory evolve from?

Multiple-Trace Theory (MTT).

What does Multiple-Trace Theory propose?

Each time a memory is reactivated, a new trace is formed, creating multiple copies of the memory across the brain.

How does having multiple memory traces help protect memory?

It offers redundancy, so that minor hippocampal damage does not erase the memory entirely.

According to Trace Transformation Theory, which memory type remains hippocampus-dependent?

Episodic or contextual memories.

Which type of memory becomes hippocampus-independent over time?

Semantic or schematic memories.

What does recent fMRI evidence suggest about hippocampal involvement?

The hippocampus/MTL shows activity when retrieving both recent and remote declarative memories.

What suggestion about hippocampal function do researchers draw from recent fMRI evidence?

Hippocampal function likely reflects a combination of SCT and TTT.

Cognitive neuroscience integrates the _________, __________, and _________ __________ of hippocampus/MTL function.

brain , cognitive theory, connectionist models