[059] Learning And Memory 1

Question 1

What is the definition of learning

Answer 1

The acquisition of new information or knowledge

Question 2

What is the definition of memory

Answer 2

The retention of learned information

Question 3

What is the definition of retrieval

Answer 3

Process necessary to recall stored memories

Question 4

What is one way to classify memories

Answer 4

Classify into
- declarative memory and
- non-declarative or procedural memory

Question 5

What is declarative memory

Answer 5

Memories for facts and events that can be accessed for conscious recollection (eg first bike was a present on 6th birthday)

Question 6

What can declarative memory be subdivided into

Answer 6

• episodic memory (recollecting specific events in time)
• semantic memory ( remembering familiar objects or facts)

Question 7

What is non-declarative or procedural memory

Answer 7

Memories that do not require conscious recollection
- including habits (eg knowing how to ride a bike)

Question 8

Model for formation of declarative memories
(Hint: relating to time)

Answer 8

• Short-term,
• long-term
• working memory

Question 9

Characteristics of short-term declarative memory

Answer 9

• lasts for minutes to hours
• easily damaged, eg by concussion

Question 10

Characteristics of long-term memory

Answer 10

• more permanent
• can last a lifetime
• has greater capacity
• quite resistant to disturbance

Question 11

What is working memory and what are some of its characteristics

Answer 11

Is a temporary “hold” of information in a “ready to use” form

• capacity is limited
• needs rehearsal
• is subject to interference

Question 12

What is amnesia

Answer 12

(Declarative memory)
Memory loss due to brain insult

Question 13

What type of memory is usually affected in amnesia

Answer 13

Declarative memory

Question 14

What are some causes of amnesia

Answer 14

• concussion
• chronic alcoholism
• tumours
• stroke

Question 15

What are the two importantly different forms of amnesia

Answer 15

• retrograde amnesia (loss of memory for events PRIOR to trauma)
• anterograde amnesia (inability to make or retrieve new memories after trauma)

Question 16

Are pure retrograde or pure anterograde amnesias rare?

Answer 16

Yes

Question 17

Can retrograde and anterograde amnesias occur together?

Answer 17

Yes.
In brain injury and disease, both forms are often seen together

Question 18

Which part of the brain is linked to working memory

Answer 18

Prefrontal cortex

Question 19

Monkeys with prefrontal lesions perform badly whilst doing what task?

Answer 19

Delayed response task
- deficits increase with delay

Question 20

What deficits do prefrontal cortex lesions in humans produce?

Answer 20

Deficits in working memory for problem solving
Eg Wisconsin card-sorting test

Question 21

Which part of the brain is associated with declarative memory

Answer 21

Temporal lobes

Question 22

Patient H.M. Is the most famous clinical case in human memory literature
What procedure was performed on him?

Answer 22

To treat severe epilepsy, he received
bilateral, medial temporal lobe resection
(Temporal lobes were the source of his epileptic discharges)

Question 23

What happened to patient H.M. after his bilateral medial, temporal lobe resection

Answer 23

Patient H.M. Had…

• partial retrograde amnesia — could recall early childhood
• profound anterograde amnesia — formed almost no new declarative memories after surgery

Retrieval mechanisms must not have been damaged as he could recall early childhood
Short-term memory was relatively normal
Various forms of procedural memory, eg mirror writing, were normal

Question 24

Medial temporal lobe structures

Answer 24

• hippocampus
• entorhinal cortex
• perirhinal cortex
• parahippocampal cortex

Question 25

What effect does bilateral medial temporal lesions in monkeys have

Answer 25

Severely impair delayed non-match to sample (DNMS) with intervals greater than 15 seconds (Mishkin, 1987) —> disturbed recognition memory in monkeys (DNMS is a test of recognising object that have been seen recently — over seconds to minutes) - very short term/ working memory still quite good - procedural memory intact

Question 26

Which are the critical structures in medial temporal lobe for human recognition memory

Answer 26

Ranking by importance level: Perirhinal cortex very important, followed by hippocampus and amygdala (less important ) Reciprocal connections make this system an associative network

Question 27

Role of diencephalon in memory

Answer 27

Medial temporal lobe structure project to thalamus and mammillary bodies - hippocampus > forbid -> mammillary bodies -> anterior nucleus of thalamus -> cingulate cortex - temporal lobe cortex, amygdala -> dorsomedial nucleus of thalamus -> prefrontal cortex Damage to either anterior or dorsomedial nuclei of thalamus, or mammillary bodies of hypothalamus also disrupt memory

Question 28

Midline thalamic lesions in monkeys produce deficits in …?

Answer 28

DNMS (Delayed non-match to sample)

Question 29

Case N.A. Was stabbed with a fencing foil through right nostril, travelled leftwards through midline and left thalamus — particularly **dorsomedial thalamus** What type of amnesia did he have

Answer 29

Severe anterograde and Retrograde amnesia for 2 years before accident

Question 30

What do studies in rats show hippocampus may be especially involved in Hippocampal lesions

Answer 30

Spatial behaviour Hippocampal lesions impair ability to solve a spatial map,, viewed as loss of spatial/ cognitive map

Question 31

What is a common cause of Korsakoff’s syndrome

Answer 31

Chronic alcoholism

Question 32

What is there a deficiency of in Korsakoff’s syndrome

Answer 32

Thiamine (vitamin B1)

Question 33

Symptoms of Korsakoff’s syndrome

Answer 33

Korsakoff syndrome is characterized by confabulation, memory loss, and gait abnormalities that are often irreversible and results if Wernicke encephalopathy is not treated adequately

Question 34

What is Korsakoff’s amnesic state

Answer 34

Amnesic state with - anterograde amnesia - limited retrograde amnesia

Question 35

Which parts of the brain are affected in Korsakoff’s amnesic state

Answer 35

Degeneration of mammillary bodies and anterior nucleus of thalamus ( some accounts include dorsomedial nucleus)

Question 36

What are other (non-amnesic) signs of Korsakoff’s syndrome

Answer 36

- ataxia (especially of gait) due to degeneration of cerebellar anterior lobe vermis Note that : gait is affected but distal limb control is not - confusion all state

Question 37

Treatment of Korsakoff’s syndrome What do you treat it with Results?

Answer 37

Treatment with vitamin B1 Can lead to remarkable and rapid recovery of motor and confusional problems, but amnesias usually persist

Question 38

What type of memory loss is lost/ affected the most in Alzheimer’s disease?

Answer 38

- retrograde amnesia spreads back in time as disease progresses - episodic memory affected most, semantic memory less so - procedural memory not impaired until final stages

Question 39

Biomolecular pathogenesis of Alzheimer’s disease

Answer 39

Neurofibrillary tangles of phosphorylated tau and extracellular plaques of beta-amyloid Disease severity correlates with tangles, not plagues

Question 40

What structures of the brain are affected first

Answer 40

Trans-entorhinal cortex, entorhinal cortex and then through cerebral cortex Also degeneration of basal nucleus of forebrain (nucleus of Meynert) cholinergic neurons, noradrenergic neurons in locus coeruleus and serotonergic Raphael neurons