Brain Damage Effects on Memory [W4]

Question 1

Name two kinds of brain tumour

Answer 1

meningiomas, infiltrating

Question 2

What are meningiomas

Answer 2

brain tumours that grow between the meninges, typically benign

Question 3

What are infiltrating tumours [brain]?

Answer 3

Brain tumours that grow within the brain tissue, difficult to remove

Question 4

Two types of strokes

Answer 4

haemorrhagic, ischemic

Question 5

What is a haemorrhagic stroke? How common? How does it damage the brain?

Answer 5

haemorrhage (bleeding), may be caused by burst aneurism, very dangerous; about ~15% of strokes; damages the brain due to lack of oxygen downstream, also ‘leaking blood’ will pool and subsequent buildup of pressure damages the brain

Question 6

What is an ischemic stroke? How common? How does it damage the brain?

Answer 6

stroke caused by a blood clot/blockage (blood supply occluded); most common ~85% of strokes; lack of oxygen to downstream parts of the brain

Question 7

What is an aneurism?

Answer 7

bulge in a blood vessel caused by a weakness in the blood vessel wall [think: radiator hose incident in my Peugeot]

Question 8

What is a stroke?

Answer 8

Loss of some blood supply to the brain, which means the “downstream” parts of the brain can’t get oxygen and glucose which are needed for brain function. This damages the brain tissue and leads to a loss of brain function; happens to varying degrees of severity

Question 9

Why does a lack of oxygen to the brain cause damage?

Answer 9

Oxygen is required to convert glucose to energy. If that energy can’t be converted (due to lack of oxygen) then it can’t power the brain which starts to “shut down” where it can’t get oxygen.

Question 10

The middle cerebral artery supplies blood to what key areas ?

Answer 10

Wernicke’s and Broca’s, etc.

Question 11

What functions might be affected by a stroke preventing bloodflow to Wernicke’s area?

Answer 11

may have difficulty with speech processing and understanding language

Question 12

What functions might be affected by a stroke preventing bloodflow to Broca’s area?

Answer 12

may have difficulty producing coherent speech

Question 13

What determines the severity of a stroke?

Answer 13

location of the stroke, amount of brain tissue that is damaged

Question 14

The basilar artery supplies blood to what key areas ?

Answer 14

brainstem (pons, medula, midbrain) and cerebellum

Question 15

What is a tumour?

Answer 15

an abnormal mass of tissue cause by excessive cell replication/growth or cells not dying off when they should; can be benign (not cancer) or malignant (cancer)

Question 16

What functions might be affected by a stroke in the anterior cerebral artery (ACA)?

Answer 16

affects motor cortex –> movement on other side of body

Question 17

What functions might be affected by a stroke in the middle cerebral artery (MCA)?

Answer 17

speech, among many other functions

Question 18

What functions might be affected by a stroke in the posterior cerebral artery (PCA)?

Answer 18

occipital cortex, vision on opposite (contralateral) hemifield

Question 19

Def: hemifield [visual field]

Answer 19

one half of the visual field; usually divided vertically through the fovea into L and R field

Question 20

What is the most common neurological disorder?

Answer 20

Alzheimer’s disease

Question 21

What causes Alzheimer’s?

Answer 21

genetic and environmental causes leading to amyloid plaques and tau tangles (buildup of protein clumps)

Question 22

What happens the the physical brain in someone with Alzheimers?

Answer 22

degeneration/loss of neurons and synapses, cortical atrophy

Question 23

What is an amyloid plaque?

Answer 23

abnormally configured proteins that form in the spaces between neurons (outside the cells)

Question 24

What are neurofibrillary tangles?

Answer 24

abnormally buildup of tau proteins inside the neuron; in healthy brains, tau binds to and stabilises microtubules. In Alzheimer’s brain, tau detached from microtubules and binds with other tau proteins.

Question 25

What’s the difference between Alzheimer’s and Dementia?

Answer 25

Alzheimer’s is a specific brain disease; Dementia is a general term for symptoms like decline in memory, reasoning or other thinking skills

Question 26

Where are plaques and tangles in Alzheimer’s patients?

Answer 26

Distributed everywhere but especially prominent in limbic areas

Question 27

Why could brain damage be considered useful (neuroscience)?

Answer 27

Effects of brain damage can help in determining the role of the affected brain areas re: behaviour

Question 28

Why could brain damage be considered useful (neuropsychology)?

Answer 28

Effects of brain damage can help in revealing how the mind is organised. ie., does damage to a specific area affect certain behaviours/functions and not others?

Question 29

Famous patient who had bilateral removal of hippocampus and surrounding cortex to control epilepsy?

Answer 29

HM reported by Scoville and Milner (1957)

Question 30

Explain patient HM (Scoville & Millner, 1957)

Answer 30

HM had severe seizures which left him unable to lead a normal life, due to a bike accident as a child. Desperate for a solution, he underwent an experimental procedure to control his epilepsy with lobotomist, William Scoville. Most of his medial temporal lobe (esp. hippocampus) was removed. Fixed seizures but left him with global anterograde amnesia (i.e., amnesia existed regardless of test type, material, or sensory modality). Forgot thing within 30 min. Severe long-term deficits (couldn’t convert to long term memory) for episodic memory (events) and semantic knowledge (new facts). Motor skills, perceptual and lexical priming, and classical conditioning unimpaired. Could learn new motor skills.

Question 31

Why was HM (Scoville & Millner, 1957) significant?

Answer 31

One of, if not the first, memory study patient; showed that new memories are generally created in the medial temporal lobe but long term memories are not stored in the hippocampus.

Question 32

def: retrograde amnesia

Answer 32

don’t remember anything that happened before brain damage

Question 33

def: anterograde amnesia

Answer 33

can’t remember events that happened after brain damage

Question 34

Who is Clive Wearing?

Answer 34

Example of severe case of anterograde amnesia

Question 35

Hippocampus is important for what role re: memory?

Answer 35

Memory consolidation, short term memory

Question 36

What structures are important in memory ?

Answer 36

perirhinal cortex (recognition); amygdala (emotional memories); basal ganglia (habit learning); hippocampus (memory consolidation and short term memory)