Week 11 - Memory and learning - finished

Question 1

Define learning

Answer 1

The acquisition of new knowledge.

The perception of an association between ourselves and our environment or between various elements of our environment.

Question 2

Define memory

Answer 2

Retention of learned information.

Adaptation of our brain circuitry to interact with our environment.

Allows us to respond appropriately, as quickly as possible, by anticipating outcomes.

Question 3

What are the 2 systems of learning? What types of information as applied to each of these systems?

Answer 3

Implicit and Explicit

Implicit:

• Declarative
• Facts
• Events

Explicit:

• Non-declarative
• Procedural
• Behaviours/skills

Question 4

What is declarative learning?

Answer 4

Recall is deliberate and usually has to do about people, places and things.
It can be easily stored and is easily forgotten.
Classified as either semantic or episodic

Question 5

What kind of information is classified in episodic declarative learning?

Answer 5

The recall of events and personal experience

Question 6

What kind of information is classified in semantic declarative learning?

Answer 6

The recall of facts and objective knowledge

Question 7

What is declarative working memory? When is it used? How is that space used? (is it always full?)

Answer 7

The working memory is perpetually used.
It stores many memories at once in multiple areas of the brain so that we aren’t consciously aware of everything.

Long term memories can be brought into the working memory as required, but are then returned to the long term memory.

The space allocated to working memory is recycled as soon as we turn our attention to something else.

Question 8

Are all working memories stored in the long term memory?

Answer 8

Working memories aren’t automatically consolidated into the long term memory, but can be stored in the short term memory with repetition, and the consolidated to the long term memory

Question 9

How many items can the average person hold in the short term memory at once?

Answer 9

5-9

Question 10

How can the volume of the short term memory be increased temporarily?

Answer 10

By chunking or categorising the information.

Question 11

How does information get consolidated from the short term memory to the long term memory? Does this vary between people?

Answer 11

It undergoes sufficient repetition, although, ‘sufficient’ repetition varies highly between people.

Question 12

Is the long term memory limited in its capacity?

Answer 12

No

Question 13

How are some better at their long term memory than others? (those special few)

Answer 13

They consolidate information directly to the long term memory without the need for repetition in the short term memory.

Question 14

How are memories stored?

What does this mean when parts of the cortex are damaged?

Answer 14

‘Cells that fire together wire together”

Memory is fragmented:

Stimulation of high order visual association cortex: patient sees things, faces or experiences

Stimulation of high order auditory association cortex: patient hears things, re-experiences conversations

The same cells that allow us to experience or perceive sensations record our experiences of them via interconnections to the cells that were simultaneously active perceiving other elements of our experience

Damage to the cortex typically only effects fragments of memories

Question 15

What are the 2 types of non-declarative/ procedural learning?

Answer 15

Associative learning:

Non-associative learning

Question 16

What is associative learning?

Is timing important?

What are the 2 types?

Answer 16

The subject learns about the relationship between two stimuli or a behaviour and its consequence

The temporal/timing relationship between the two stimuli is critical

2 Types:

• Operant
• Classical conditioning

Question 17

What is non-associative learning?

Is timing important?

What are the 2 types?

Answer 17

The subject learns about the properties of a single stimulus. Subjects learn about the properties of a single stimulus so that repeated administration of the same stimulus results in a different response

The timing of the stimulus is inconsequential

2 Types:

• Habituation
• Sensitisation

Question 18

What is operant associative learning? E.g.?

Answer 18

Trial and error: spontaneous behaviour which occurs in the first instance without identifiable stimulus

e.g.
Rat in a cage. Accidentally pulls lever. Food drops. Will repeat.

Question 19

What is classical conditioning? What type of learning is it? E.g.?

Answer 19

It is procedural/non-delcarative associative learning

Learning to associate two stimuli

Unconditioned stimulus  (US)
	typically evokes a strong response in subject without training, this will become the learned response to the conditioned stimulus.
Pavlov’s dog: US = meat

Conditioned stimulus (CS)
	typically evokes a weak response in subject which is not related to the response which will be learned
Pavlov’s dog: CS = bell

Conditioning
repeatedly ring bell & present the dog with meat ie. Train the dog to associate the two stimuli

Post conditioning
dog has learned to associate the two stimuli…ring bell, withhold meat….dog still salivates

Question 20

What is extinction in terms of classical conditioning?

Answer 20

Extinction is the undoing of classical conditioning

Procedure:

• CS
• Withhold US
• Repeated
• Results in no response to CS

Question 21

What is Habituation?

Answer 21

A decrease in a response to a benign stimulus when repeatedly applied.

E.g. when you first hear fireworks they might be scary but if you hear them a few times they don’t provoke the same scary response because you have been conditioned to recognise that they are not threatening.

Question 22

What is the physiological process involved in habituation?

Answer 22

This is the depression of the synaptic transmission through the reduction of neurotransmitter released from the input neuron. This requires presynaptic modification.

The presynaptic membrane ion channels are inactivated by:

• a decreased ability to mobilise synaptic vesicles into active zones.
• a decreased ability to release neurotransmitters.

Question 23

Is habituation short or long term typically?

Answer 23

Short term and usually only lasts for a few minutes after the stimulus is withdrawn

Question 24

How does long term habituation occur? What is the physiological process that happens?

Answer 24

It happens after long term exposure to a stimulus and results in long term changes to the synapse.

This happens by:

• a decrease in the number of synapses due to a withdrawal of axons
• a decrease in active zones in the remaining synapses

Question 25

What is sensitisation?

What is the physiological process that happens here?

Answer 25

An increase in the response to various stimuli following the application of an intense or noxious stimulus.

e.g. a person is habituated to fireworks and then sounds really loud and hurts them, the next time the sound of fireworks will cause an increased response to them.

The process is:

• Serotonin release
• Acts on G protein coupled receptors
• Activates 2nd messenger cascade
• Prolongs the presynaptic action potential
• Increases the ability to mobilise synaptic vesicles into active zones
• Increases ability to release neurotransmitter
• Generates larger postsynaptic potential

Question 26

What are the physiological changes that occur with long term sensitisation?

Answer 26

Increased number of synapses
Increased number of dendrites on the post synaptic neuron
Increased number of active zones on the presynaptic neuron to allow greater mobilisation of vesicles.

Question 27

What is retrograde amnesia?

Answer 27

The memory loss and resultant incapacity with retrograde amnesia tends to be relatively minor

Memory appears to be stored in multiple areas of the brain

Believed to be stored in higher order association cortices

Semantic memories of a particular stimulus appear to be fragmented and stored in relevant cortices eg. Kluver – Bucy syndrome

Episodic memories appear to be stored in prefrontal cortex

Question 28

What is anterograde amnesia? Where does the damage usually occur?

What is it associated with lesions of? Name 3

Answer 28

Tends to be due to damage to much smaller area of cerebrum

Deficit tends to be much more incapacitating

Associated with lesions of:

Hippocampus - needs to be bilateral - mild deficit
Perirhinal cortex - most profound deficit
Enterorhinal cortex - first area affected by Alzheimer’s
Mamillary bodies - mild deficit
Medial thalamus - major deficit
- anterior nucleus
- dorsomedial nuclei
- any one of these nuclei gives milder but still significant deficit

Question 29

What is the role of the hippocampus in memories? How does it differ between the sides? (dominant or non dominant)

Answer 29

Appears critical in the consolidation of declarative memories
We may be able to consciously increase its function (basal nuclei of the amygdala)

Function appears to be slightly different from dominant to non-dominant sides or left to right, it is not clear which at this stage

Appears to vary but one appears to have a greater function in verbal memory and one appears to play a large role in spatial orientation

Question 30

What types of memory the hippocampus NOT important in?

Answer 30

Working memory
Procedural memory
Memory not stored here

Question 31

What do lesions of the hippocampus produce in terms of memory?

Answer 31

Severe retrograde amnesia but lesions must be bilateral to affect memory severly