5C: The role of episodic and semantic memory in remembering and imagining

What is episodic memory?

Memory of distinct personal events tied to specific times and places.

What is semantic memory?

Organised factual knowledge about the outside world.

How do episodic and semantic memory contribute to autobiographical memory?

They work together to form personal life histories using both specific events and general knowledge.

What is autobiographical memory?

A memory system combining episodic and semantic memories to form a personal life narrative.

Which brain area is primarily involved in retrieving episodic memories?

The hippocampus.

Which brain areas are involved in retrieving semantic memories?

The frontal and temporal lobes.

What happens in the brain during autobiographical memory retrieval?

Both the hippocampus and frontal/temporal lobes are activated.

Why is autobiographical memory fallible?

Because it is reconstructed from fragments, not replayed exactly.

What is memory reconstruction?

The process of rebuilding a memory using snapshots and semantic info, which may lead to inaccuracies.

What are false memories?

Inaccurate recollections influenced by suggestion or error in reconstruction.

What is episodic future thinking?

Projecting yourself forward in time to imagine personal future events.

What is mental time travel?

The ability to mentally project oneself backward or forward in time to remember or imagine events.

What activates episodic future thinking?

Questions about personal future scenarios (e.g. “What will you do this weekend?”).

Do autobiographical and episodic future thinking share brain regions?

Yes, they involve the same brain areas.

How do we use the past to imagine the future?

We rearrange past memories to create possible future scenarios.

What does amnesia reveal about memory and future thinking?

People with amnesia often struggle both to recall the past and to imagine the future.

Why is imagining the future beneficial?

It helps anticipate challenges and plan steps, offering an evolutionary advantage.

How does future thinking relate to human behaviour?

It allows flexible, goal-directed behaviour based on imagined future outcomes.

What is dementia?

A neurodegenerative disease causing progressive neuron loss and cognitive decline.

What is Alzheimer’s disease?

The most common form of dementia, with symptoms like memory loss, confusion, and disordered thinking.

What causes dementia and Alzheimer’s?

Brain damage, disease, toxins, or reduced blood supply to the brain.

What areas are affected in Alzheimer’s disease?

Hippocampus, prefrontal cortex, temporal lobes, and eventually the entire brain.

What are early symptoms of Alzheimer’s?

Forgetfulness and short-term memory loss.

What are mid-stage symptoms of Alzheimer’s?

Increasing trouble remembering things and possible confusion.

What are late-stage symptoms of Alzheimer’s?

Severe memory loss, disorientation, and inability to recognise familiar people.

What are amyloid plaques?

Protein fragments that accumulate between neurons and disrupt communication.

What are neurofibrillary tangles?

Twisted fibers inside neurons that lead to cell death.

What is the result of hippocampal cell loss?

Brain atrophy and disrupted memory formation.

How does damage to the temporal lobes affect the hippocampus?

It isolates the hippocampus, impairing memory processing.

How do lesions in the frontal lobes affect cognition?

They cause memory loss, difficulty focusing, and movement issues.

Why is the hippocampus critical in Alzheimer’s?

It's one of the first regions to shrink, leading to anterograde amnesia.

What is anterograde amnesia?

The inability to form new memories.

What is retrograde amnesia?

The inability to recall old memories.

What happens when neuron loss spreads to the cerebral cortex?

Loss of old memories, attention issues, personality changes.

What causes death in final-stage Alzheimer’s?

Damage to the hindbrain, which controls vital functions like breathing and heart rate.