11: Learning, Memory, and Amnesia

Question 1

What is learning?

Answer 1

A process whereby changes in the brain are initiated by experience.

Question 2

What is memory?

Answer 2

The storage and reactivation of the learning changes.

Question 3

What is amnesia?

Answer 3

A pathological loss of memory.

Question 4

What surgery did HM have done on his brain?

Answer 4

• Bilateral medial temporal lobectomy.

- This removed most of the hippocampus.

Question 5

What is the difference between a lobectomy and a lobotomy?

Answer 5

Lobectomy is the removal of a lobe or most of it.

Lobotomy is the separation, but not removal, of a lobe or most of it from the rest of the brain.

Question 6

What type of amnesia did HM have post-surgery?

Answer 6

Anterograde amnesia for long-term memories.

Question 7

What is a well-established test for verbal long-term memory?

Answer 7

The digit span + 1 test.

Question 8

What is memory consolidation?

Answer 8

The transposition of short-term memories into long-term memories.

Question 9

What do repetition priming tests measure?

Answer 9

Implicit memory.

Question 10

What are semantic memories?

Answer 10

Explicit memories for general facts and information.

Question 11

What are episodic memories?

Answer 11

Explicit memories for particular events in one’s life.

Question 12

What is cerebral ischemia?

Answer 12

An interruption in the blood supply to the brain.

Question 13

What type of amnesia does cerebral ischemia cause?

Answer 13

Medial temporal lobe amnesia.

Question 14

What damage is associated with Korsakoff’s syndrome (3)?

Answer 14

Damage to the medial diencephalon, cerebellum, and hippocampus.

Question 15

Aside from medial temporal lobe amnesia, what else develops in Korsakoff’s syndrome?

Answer 15

Severe retrograde amnesia.

Question 16

What causes the reduction of acetylcholine levels in the brains of Alzheimer’s patients?

Answer 16

The degeneration of the basal forebrain.

Question 17

What is post-traumatic amnesia (PTA)?

Answer 17

Amnesia caused by concussion blows.

Question 18

What are ‘Islands of memory’?

Answer 18

Surviving memories for isolated events that occurred during periods for which other memories have been wiped out.

Question 19

What is Hebb’s theory of memory consolidation?

Answer 19

Memories are initially stored in short-term storage, but their structure changes, by means of reverberating, become accessible in the long-term storage.

Question 20

What is a commonly-used controlled method for studying memory consolidation?

Answer 20

Electroconvulsive shock (ECS)

Question 21

What is the ‘standard consolidation theory’?

Answer 21

Short-term memories reside temporarily in the hippocampus until they become long-term memories, stored somewhere more stable in the brain.

Question 22

What does the ‘multiple trace theory’ propose?

Answer 22

The hippocampus and other cortical systems responsible for memory storage will keep memories for as long as they exist.

Question 23

What is an ‘engram’?

Answer 23

A change in the brain that stores a memory.

Question 24

What does the ‘delayed nonmatching-to-sample test’ measure?

Answer 24

Object recognition abilities.

Question 25

What type of brain damage reduced object recognition abilities?

Answer 25

Removal of the medial temporal lobes (like HM).

Question 26

What is the Mumby box?

Answer 26

The rat version of the delayed nonmatching-to-sample test.

Question 27

Cerebral ischemia leads to a loss of...

Answer 27

CA1 hippocampal pyramidal cells.

Question 28

What are the two cortexes that make up the rhinal cortex?

Answer 28

- Entorhinal (within the cortex) | - Perirhinal (surrounding the cortex)

Question 29

Which rhinal cortex plays a role in object recognition?

Answer 29

The perirhinal cortex.

Question 30

Rats with hippocampal lesions have serious deficits in what 2 types of memory?

Answer 30

Reference and working memory.

Question 31

What are place cells?

Answer 31

Neurons that are fired only when an individual is in a specific location.

Question 32

What is the cognitive map theory?

Answer 32

Hippocampus is a part of the brain that has been specialized for spatial cognition.

Question 33

Two major findings about memory storage...

Answer 33

- Memories are diffusely stored, so damage in one area of brain doesn't mean loss of memory. - Memories are increasingly resistant to destruction over time.

Question 34

What role does the amygdala have in memory?

Answer 34

Emotional significance of memories.

Question 35

Prefrontal cortex may have a role in which two types of memory?

Answer 35

Working and temporal memory.

Question 36

What is the cerebellum's role in memory storage?

Answer 36

Stores memories for learned sensorimotor skills.

Question 37

What is the striatum's role in memory storage?

Answer 37

Habit-formation memories.

Question 38

What did Hebb argue was the basis for long-term memory?

Answer 38

Changes in the efficiency of synaptic transmission.

Question 39

What is long-term potentiation (LTP)?

Answer 39

High-frequency electrical stimulation to presynaptic neurons induced by synaptic transmission.

Question 40

Why is LTP so widely studied?

Answer 40

Because they are very similar to Hebb's theory of synaptic changes for long-term memory.

Question 41

What are the two key properties of LTP?

Answer 41

- It can last for months if successful. - Successfully develops only if postsynaptic firing follows presynaptic firing. (Co-occurrence, a.k.a Hebb's Postulate for Learning')

Question 42

What is the NMDA receptor?

Answer 42

- Receptor for glutamate | - Prominent at synapses, hence its significance for LTP.

Question 43

NMDA receptors do not respond effectively unless 2 things co-occur...

Answer 43

- Glutamate is bound to the receptor. | - Postsynaptic neuron must already be partially depolarized.

Question 44

Why is it important that postsynaptic neurons must already be partially depolarized for a successful LTP?

Answer 44

- Enables the generation of associations in the neural network. This is the foundation for a LTP to last.

Question 45

What is long-term depression (LTD)?

Answer 45

- Opposite of LTD. | - Prolonged co-occurrence of low-frequency stimulation of presynaptic neurons.

Question 46

Which amnesic patient seemed to provide strong evidence for the involvement of the hippocampus in memory?

Answer 46

R.B.