introduction to cognitive neuropsychology

Question 1

what is cognitive neuropsychology?

Answer 1

the study of the structure and function of the brain as it related to perception, reasoning, remembering, and all other forms of knowing and awareness

Question 2

what is amnesia?

Answer 2

a general term that describes memory loss

Question 3

causes of amnesia

Answer 3

organic
- acute damage to the brain
- degenerative disease
psychogenic (purely psychological)

Question 4

forms of amnesia

Answer 4

retrograde & anterograde

Question 5

what is pronounced anterograde amnesia?

Answer 5

inability to encode/retrieve memories for events encountered for after the onset amnesia

Question 6

what is variable retrograde amnesia?

Answer 6

inability to retrieve memories acquired before the onset of amnesia

Question 7

main features of the amnesic syndrome

6 features

Answer 7

1. pronounced anterograde amnesia
2. variable retrograde amnesia
3. intact short-term memory
4. preserved general intelligence (IQ)
5. skills such as driving and playing music unaffected
6. some residual learning capacity

Question 8

what parts of the brain are important for memory

5 parts

Answer 8

1. amygdala
2. basal ganglia
3. cerebellum
4. frontal lobes
5. occipital lobes

Question 9

function of amygdala

Answer 9

emotional content of episodic memories

Question 10

function of basal ganglia

Answer 10

important for learning motor skills

Question 11

function of cerebellum

Answer 11

memory for automatised skills

Question 12

function of the frontal lobes

Answer 12

working memory; source montoring; prospective memory

Question 13

function of the occipital lobes

Answer 13

visual perceptual representation memory

Question 14

effects of damage to the hippocampus

4 effects

Answer 14

• Henry Molaison had his medial temporal lobes (2/3 of the hippocampus)
• his epilepsy improved, personality unchanged, IQ increased
  However:
• unable to encode/retrieve new episodic memories
• developed severe anterograde amnesia

Question 15

other aspects of Henry Molaison’s memory

3 aspects

Answer 15

• developed retrograde amnesia for the period 10-15 years prior to the operation
  still normal:
• STM
• learning of new procedural memories

Question 16

what is Korsakoff’s syndrome caused by?

Answer 16

thiamine deficiency (usually due to alcoholism)

Question 17

what is Korsakoff’s syndrome?

Answer 17

damage to the diencephalon
- patients often appear to be drunk, uncoordinated, confused

Question 18

amnesia in Korsakoff’s

3 points

Answer 18

• STM normal
• encoding/retrieval of new episodic long-term memories impaired (anterograde amnesia)
• temporal gradient of retrograde amnesia

Question 19

temporal gradient of retrograde amnesia:

Answer 19

Recall for events in the time immediately leading up to its onset very poor, but earlier memories relatively intact

Question 20

what is viral encephalitis?

2 points

Answer 20

• sudden onset of acut fever, headache, nausea
• usually extensive bilateral temporal lobe damage

Question 21

how is viral encephalitis caused?

Answer 21

• caused by herpes crossing blood-brain barrier

Question 22

amnesia due to viral encephalitis:

3 points

Answer 22

• particularly severe amnesic disorder
• similar to Korsakoff’s, but better insight, and flatter temporal gradient
• often deficits of spatial and semantic memory, e.g., surface dyslexia; problems with face recognition

Question 23

common types of dementia

4 types

Answer 23

• alzhermer’s
• vascular
• mixed alzheimer’s & vascular
• lewy body dementia

Question 24

amnesia due to dementia

3 points

Answer 24

• progressive neural disease
• general degeneration of the brain; atrophy due to growth of neural plagues & tangles
• pattern of impairment involves ‘information-processing’ deficits superimposed upon an amnesic syndrome

Question 25

what is transient global amnesia?

Answer 25

sudden onset of anterograde amnesia and retrograde amnesia for recent events preceding attack

Question 26

features of transient global amnesia | 6 features

Answer 26

1. no loss of personal identity; recognition of family 2. anxious, agitated 3. resolves within 12 hours 4. rare 5. mostly over 50s - often men 6. triggers emotional upset

Question 27

what is transient global amnesia caused by?

Answer 27

disruption of blood flow to thalamic/medial temporal cortex

Question 28

what does amnesia provide evidence for?

Answer 28

amnesia provides evidence for a dissociation between STM and LTM

Question 29

What traits to amnesics have but poor episodic and semantic memory? | 3 traits

Answer 29

– show normal sized priming effects – still have motor memory (skills), such as making a telephone call or making coffee (procedural memory) – can learn new procedural skills such as tracking a moving target in the pursuit rotor task

Question 30

what do the amnesic traits show

Answer 30

it shows the dissociation between explicit memory and implicit memory

Question 31

theories of anterograde amnesia: why can't amnesics encode/store/retrieve new episodic memories? | 4 points

Answer 31

1. faulty encoding 2. accelerated forgetting 3. faulty retrieval 4. faulty encoding/storage of contextual information

Question 32

accelerated forgetting | 2 points

Answer 32

- Some studies show that patients with hippocampal lesions forget faster than controls, even after material has been adequately learned - In other studies various different types of amnesics forget at the same rate as controls, provided initial learning is adequate

Question 33

transient amnesia and retrieval deficit

Answer 33

Transient amnesia shows that retrieval deficits can cause amnesia – once amnesia resolves, memories that were unavailable can be retrieved normally

Question 34

what did Warrington and Weiskrantz 1970 suggest?

Answer 34

Warrington and Weiskrantz 1970 suggested that retrieval deficit is due to response competition. partial information (e.g. 1st letter of studied word) helps overcome competition

Question 35

Could retrieval difficulties be related to absence of contextual information?

Answer 35

contextual information allows us to distinguish between otherwise similar memories

Question 36

encoding specifity principle:

Answer 36

LTM is generally better when context at retrieval and encoding match

Question 37

deficit in encoding/retrieving context: Hupper and Piercy

Answer 37

Huppert and Piercy (1976): suggested that amnesia is due to the inability to encode and retrieve contextual information

Question 38

conextual deficit theory: problems | 4 problems

Answer 38

1. semantic memories can also be impaired, but these are not contextual 2. definition of context is vague 3. why remember a stimulus but not its context? 4. context-processing deficits vary substantially across patient groups

Question 39

what is a temporal gradient in retrograde amnesia?

Answer 39

a pattern of retrograde amnesia characterized by greater loss of memory for events from the recent past

Question 40

temporal gradient in retrograde amnesia (patient PZ)

Answer 40

Patient PZ’s retrograde amnesia gradient for information from his published autobiography. The earlier the information the better it is recalled

Question 41

Ribot's (1881) law of retrograde amnesia

Answer 41

recent memories are more likely to be lost (opposite of normal forgetting)

Question 42

what may a temporal gradient be due to?

Answer 42

temporal gradient may be due to slow-scale consolidation process -> earlier memories have had longer to be consolidated

Question 43

Standard Consolidation Theory (Dudai, 2004; Squire, 1992) | 3 points

Answer 43

1. Episodic memories are initially encoded and stored in hippocampus, and retrieving these memories requires reactivating the hippocampus 2. Over time, the hippocampal memory trace becomes less important, and the cortex can retrieve the memory without the hippocampus 3. Consequently, older memories are spared in retrograde amnesia

Question 44

what what are the two types of psychogenic amnesia? | 2 types

Answer 44

- fugue states - dissociative amnesia

Question 45

Psychogenic amnesia: Fugue states | 5 effects

Answer 45

* Sufferer typically found wandering, often a long way from home. * Triggers include severe stress, depressed mood, history of transient organic amnesia * Lasts a few hours or days (can be longer). * After recovery, memories from the fugue state are lost. * Very rare.

Question 46

Psychogenic amnesia: Dissociative type | 3 points

Answer 46

* Refers to loss of memory for specific events due to trauma (no anterograde amnesia). * 25-45% of homicide suspects claim amnesia for the crime! * No cases reported before 1800: “dissociative amnesia is not a natural neuropsychological phenomenon, but instead a culture-bound syndrome, dating from the 19th century” (Pope et al., 2007).

Question 47

Amnesia summary

Answer 47