Amnesia

Question 1

Memory forms who we are. True or false?

Answer 1

True.

Question 2

There are 2 types of amnesia. What are they?

Answer 2

1. Psycogenic

2. Organic

Question 3

Define psycogenic amnesia.

Answer 3

Also called dissociative amnesia. This is a sudden loss of autobiographical memories. This can last for hour to years. There is no physical damage in psycogenic memory loss, it has been internally generated.

Question 4

What kind of disorders are associated with psycogenic memory loss?

Answer 4

Multiple personality disorder.

Question 5

Define organic amnesia.

Answer 5

The loss of memories due to biological processes such as strokes, disease, trauma etc.

Question 6

What are the 2 types of organic amnesia?

Answer 6

1. Transient

2. Persistent

Question 7

Define transient amnesia.

Answer 7

The temporary but almost total loss of short-term memory, often accompanied by problems in accessing older memories also.

Question 8

Give an example of transient amnesia.

Answer 8

In epilepsy.

Question 9

Define persistent amnesia. What are the 2 types?

Answer 9

Amnesia that is permanent. The two variations are:

1. Degenerative, e.g. diseases like Alzheimer’s
2. Non-degenerative e.g.

Question 10

Define persistent amnesia. What are the 2 types?

Answer 10

Amnesia that is permanent. The two variations are:

1. Degenerative, e.g. diseases like Alzheimer’s
2. Non-degenerative

Question 11

There are 2 classes of non-degenerative, persistent amnesia. What are they?

Answer 11

1. Material specific: results in a naming impairment with respect to materials.
2. Global: this is the ‘classic’ amnesia, whereby there is a loss of all new learning

Question 12

Where is the hippocampus?

Answer 12

In the medial temporal lobe.

Question 13

The hippocampus is placed at the end of the visual system in primates. True or false?

Answer 13

True.

Question 14

Define Korsakoff syndrome.

Answer 14

Chronic memory loss caused by thiamine deficiency. This can be caused by alcohol misuse.

Question 15

What is the Papez circuit?

Answer 15

The neural circuit that controls emotional expression. It has been found this circuit is extremely important in memory.

Question 16

Define organic amnesia.

Answer 16

The loss of memories due to physical/biological damage.

Question 17

Give 5 common causes of non-degenerative, persistent organic amnesia.

Answer 17

1. Head trauma or surgery
2. Viral disease
3. Ischaemia (loss of blood flow)
4. Anoxia (loss of oxygen)5. Nutrient deficiency

Question 18

What happens if you remove the temporal lobe?

Answer 18

It causes amnesia.

Question 19

What happens if you damage the hippocampus?

Answer 19

It causes amnesia.

Question 20

A small amount of damage in a specific area can be more harmful than extensive damage. True or false?

Answer 20

True.

Question 21

Some functions are spared in amnesia. These can be assessed in tests. a) What is the digit span test?
b) How do amnesiacs fare in the digit span test?

Answer 21

a) Patients are asked to remember short series of numbers.

b) Usually they perform very well.

Question 22

Some functions are spared in amnesia. These can be assessed in tests. a) What is the corsi block test?
b) How do amnesiacs fare in the corsi block test?

Answer 22

a) The patient has to mimic a researcher in tapping a sequence of identical blocks
b) Usually they perform very well

Question 23

Why do amnesiacs generally perform well in the digit span and corsi block tests?

Answer 23

The parietal cortex is involved which is not the area that has been damaged in amnesia.

Question 24

Some functions are spared in amnesia. These can be assessed in tests. a) What is the digit span test?

b) What kind of memory does it test?
c) How do amnesiacs fare in the digit span test?

Answer 24

a) Patients are asked to remember short series of numbers.
b) Short-term memory
c) Usually they perform very well.

Question 25

Some functions are spared in amnesia. These can be assessed in tests. a) What is the corsi block test? b) What kind of memory does it test? c) How do amnesiacs fare in the corsi block test?

Answer 25

a) The patient has to mimic a researcher in tapping a sequence of identical blocks b) Short-term memory c) Usually they perform very well

Question 26

a) What is the star test? b) What is the point of the star test? c) How do amnesiacs perform?

Answer 26

a) A subject is asked to draw a star. They cannot see what they're doing directly, the hand is covered by a screen, but they can see what they're doing in a mirror. b) To test procedural memory c) Very well, although they do not remember the test afterwards.

Question 27

Perceptual priming can be tested. a) Give an example of this. b) How do amnesiacs fare? c) What does this show?

Answer 27

a) A subject is shown a sequence of dotted pictures. In each frame there are more dots than before that begin to build up an image. b) With each repetition of the test they begin to see the image much earlier on, even though they do not remember doing the test before. c) Priming seems unaffected by amnesia

Question 28

a) What is the weather prediction task? b) How did amnesiacs fare? c) How did Parkinson's and Huntingdon's patients fare? Why?

Answer 28

a) A subject is asked to predict the weather based on 4 different tarot cards. Rules must be learned. b) They could learn the rule but no recognise associated stimuli c) They could not learn the rule but could recognise the stimuli. These patients lack basal ganglia.

Question 29

Define a) anterograde and b) retrograde amnesia.

Answer 29

a) A loss of ability to create new memories after the event that caused the amnesia. 'No memories after the lesion'. b) Loss of ability to recall memories prior to the lesion.

Question 30

There are 2 types of episodic memory. Thus define a) anterograde and b) retrograde amnesia.

Answer 30

a) A loss of ability to create new episodic memories after the event that caused the amnesia. 'No memories after the lesion'. b) Loss of ability to recall episodic memories prior to the lesion.

Question 31

Define semantic memory.

Answer 31

A portion of long-term memory that gives the ability to recall information and ideas that are not based on personal experience.

Question 32

Episodic and semantic memory fall under which category of memory?

Answer 32

Declarative.

Question 33

Explain the difference between a) familiarity and b) recollection. Give examples.

Answer 33

a) Familiarity is a feeling that something is familiar although no details of it have been retained. For example you may recognise someone's face but not know why. b) Recollection is a rich, detailed remembering of a past event. For example when you recognise someone's face you remember who they are and when you last saw them.

Question 34

Explain the 2 theories of how semantic memory is stored.

Answer 34

1. The hippocampus encodes semantic memories which are then stored in the cortex for recall. This is how episodic memory works. 2. The hippocampus is not involved in encoding semantic memory. This was shown in experiments whereby amnesiacs with hippocampal damage but some spared parahippocampal cortex (part of the hippocampal system) were able to recall limited semantic memory.

Question 35

Define memory consolidation and the general 2-stage mechanism behind it.

Answer 35

Consolidation is the process of stabilising a memory trace after it is acquired.

Question 36

Define memory consolidation and the general 2-stage mechanism behind it.

Answer 36

Consolidation is the process of stabilising a memory trace after it is acquired. First synaptic consolidation must occur, whereby the synapse changes in learning and the hippocampus encodes the memory. Then systems consolidation occurs whereby stored memories becomes independent of the hippocampus, i.e. they are stored in the cortex.

Question 37

Amnesiacs only ever suffer from either antero or retrograde amnesia. True or false?

Answer 37

False: most amnesiacs suffer from a bit of retrograde amnesia, even if they have primarily anterograde amnesia.

Question 38

a) Define memory consolidation and b) the general 2-stage mechanism behind it.

Answer 38

Consolidation is the process of stabilising a memory trace after it is acquired. b) First synaptic consolidation must occur, whereby the synapse changes in learning and the hippocampus encodes the memory. Then systems consolidation occurs whereby stored memories becomes independent of the hippocampus, i.e. they are stored in the cortex.

Question 39

Define multiple trace theory (MTT).

Answer 39

Each time information is presented it is neutrally encoded in a unique memory trace composed of a combination of its attributes. Basically each time you're presented with something it adds to the combination of memories you already have of that thing.

Question 40

What is hypothesised about episodic memory in terms of consolidation?

Answer 40

Episodic memories are never fully consolidated and thus do not become fully independent of the hippocampus. An example of this is the visual-spatial details of events - you can never fully remember them.

Question 41

Why is it thought that episodic memories can never be fully consolidated?

Answer 41

Due to the multiple traces of the same event. They all vary slightly.

Question 42

Why is it thought that episodic memories, particularly visual-spatial details, can never be fully consolidated?

Answer 42

Due to the multiple traces of the same event. They all vary slightly.

Question 43

What effect does amnesia have on imagination and scene construction?

Answer 43

Patients cannot imagine a whole scene, but can imagine single objects.

Question 44

The hippocampus is involved in mental scene construction. True or false?

Answer 44

True.

Question 45

Why is it amnesiacs can usually recall retrograde memories from the distant past?

Answer 45

Because they have long been consolidated.

Question 46

How long does consolidation take?

Answer 46

Between a period of weeks to years, depending.

Question 47

Why is it amnesiacs can usually recall retrograde memories from their remote past?

Answer 47

Because they have long been consolidated.