UNIT 3, AOS2, Dot point 6 (The role of episodic and semantic memory)

Question 1

What can brain imaging show us?

Answer 1

Brain imaging can show tumours, shrinkage, inactivity, and lesions.
Brain lesions are damaged areas of brain tissue, often seen as dark spots on scans. They can cause issues like seizures or loss of function — for example, in Alzheimer’s disease.

Question 2

What is Alzheimer’s disease and how does it affect memory?

Answer 2

Alzheimer’s disease is a neurodegenerative disease that causes neuron loss in the hippocampus, leading to memory loss and personality changes. It first affects episodic memory, and later also impacts semantic memory.

Question 3

What causes Alzheimer’s disease?

Answer 3

Amyloid plaques (protein build-up between neurons)

Neurofibrillary tangles (twisted fibres inside neurons)

Cortical shrinkage (brain tissue loss)

loss of neurons

Question 4

How is Alzheimer’s disease diagnosed?

Answer 4

Brain imaging can show lesions caused by amyloid plaques, but Alzheimer’s is best confirmed through a post-mortem examination.

A post-mortem examination is a medical examination of a body after death to find out the cause of death or to study diseases like Alzheimer’s.

Question 5

What are the symptoms of Alzheimer’s disease?

Answer 5

Memory loss (especially declarative memories)

Personality changes

Confusion and disorientation

Repetition of questions or actions

Question 6

What is aphantasia?

Answer 6

Aphantasia is a rare condition where a person cannot create visual images in their mind — they are unable to picture things mentally.

Question 7

What causes aphantasia and how does it affect memory?

Answer 7

Aphantasia is linked to the visual cortex in the brain, not the eyes. People are usually born with it, but it can also happen after a brain injury.
It affects memory by making it harder to remember personal events (episodic memory) and to imagine future events.