Chapter 8 - Learning and Memory

Question 1

How long does sensory memory last?

Answer 1

Less than a second

Question 2

How long does STM last?

Answer 2

1 minute

Question 3

How long does LTM last?

Answer 3

A lifetime

Question 4

List 3 traits associated with STM

Answer 4

1. Limited capacity
2. Fades quickly without rehearsal or attention
3. Once it is forgotten, it is lost. No physical trace.

Question 5

List 3 traits associated with LTM.

Answer 5

1. Large capacity
2. Does not fade in the absence of attention.
3. You may remember something you thought you had forgotten (with a hint).

Question 6

List 2 components of implicit memory.

Answer 6

Procedural memory - motor skills

Priming - exposure to one stimulus influences the response to another stimulus

Question 7

What is declarative memory involved with?

Answer 7

Facts and events

Question 8

List 2 components of declarative memory and what they deal with.

Answer 8

Episodic memory - events

Semantic memory - facts

Question 9

List 3 traits related to classical conditioning

Answer 9

1. Involves placing a neutral signal before a reflex
2. Focuses on involuntary, automatic behaviours (reflexes)
3. Described by Pavlov

Question 10

List 3 traits related to operant conditioning

Answer 10

1. Involves applying reward or punishment after a behaviour
2. Focuses on voluntary behaviour
3. Described by Skinner

Question 11

What are brain areas involved in memory?

Answer 11

Hippocampus, basal ganglia

Question 12

What is the word used to describe a physical representation of what has been learned?

Answer 12

Engram.

Question 13

What was done to test the hypothesis that the engram of classical conditioning involved new connections in the brain linking the conditioned stimulus and conditioned response? What was found?

Answer 13

Lashley made cuts all around a rat’s brain, trying to break conditioned behaviuors. Found that no memories were lost and hence concluded that memory does not depend on connections with the brain.

WRONG

Question 14

What was being done to test the hypothesis that certain brain regions may contain the memories?

Answer 14

Removing different parts of the brain after learning

Found that memory loss was a function of the amount of tissue removed –> memory does not rely on a single area, but rather on all areas equally

WRONG bc cortex isnt the only place the look at and different memories have different mechanisms

Question 15

In classical conditioning, where does learning take place?

Answer 15

Synapse between cerebellum and red nucleus

Question 16

Describe the steps leading to learning and their locations (3).

Answer 16

1. Lateral Interpositus Nucleus of Cerebellum (LIP)
   - LIP sends projections to the red nucleus.
2. Red nucleus
   - motor nucleus in midbrain
   - generates fibres that goes to spinal cord

Question 17

What was observed in the rabbit experiment when

a) LIP of the rabbit was temporarily suppressed?
b) red nucleus was suppressed?

Answer 17

a) suppress LIP –> was showed conditioned stimulus and and unconditioned stimulus –> no responses during training –> waited for LIP to recover and continue training –> rabbit began to learn but at the same rate as those who never received training

SUPPRESSION OF LIP: NO LEARNING

b) suppress red nucleus –> rabbit showed no response during trainig
however, as soon as the red nucleus had recovered from the cooling of drugs, the rabbit shows strong learned responses to the tone. suppressing the red nucleus temporarily prevented response but not learning

Question 18

Damage to LIP: no _______?

Damage to red nucleus: no __________?

Answer 18

response and learning

response (motor nucleus broken, cannot blink even with puff of air). got normal learning

Question 19

List 2 areas necessary for the learning of classical conditioning.

Answer 19

cerebellum

basal ganglia

Question 20

When does the basal ganglia take over in the learning of classical conditioning?

Answer 20

when the delay between the conditioned stimulus and unconditioned stimulus is longer than 2 seconds, the cerebellum recruits another structure for learning: basal ganglia

Question 21

What is the basal ganglia involved in?

Answer 21

Implicit memory

Question 22

Describe the weather prediction task and how it shows the importance of the basal ganglia in implicit learning.

Answer 22

Given 4 cards and asked to determine whether it will rain or not.

Participants quickly figure out that 1 or 2 of the cards are quite informative, and start following them (ie every time the triangles appear, I will say it will rain). Will lead to 62.5 % accuracy in their prediction

Slowly, over time, participants start increasing their performance. They begin to include information from other cards into their decisions. They may not be aware of this, but it happens anyways. If you ask them why they respond in a certain way, they may say they have a “hunch”.

Question 23

How will people with Parkinson’s disease respond to the Weather Prediction Task?

Answer 23

They have impairments with the basal ganglia. They will have no problem forming the initial rule (eg triangles = rain) but they will not be able to improve beyond that.

They can still form the initial rule because their hippocampus is intact anyway. but they will never be able to incorporate unconscious info that normal ppl will be able to.

Question 24

Which area is involved in explicit learning?

Answer 24

Hippocampus

Question 25

What was observed when areas adjacent to patient HM's hippocampus were removed?

Answer 25

Researchers visited his house almost 200 times, but each time is like the first. - He does not consciously remember them, but has some record of the experience based habits, interactions, values, emotions. - Trust these researchers subconsciously even though he doesn't consciously rmb seeing them before - There is some rapport and he is aware of the positive relationship on some level. - Shows some emotional response that wasn't present initially

Question 26

When the hippocampus is removed, what can still remain intact?

Answer 26

1) working memory 2) procedural memory 3) better implicit than explicit memory

Question 27

Distinguish between anterograde and retrograde amnesia

Answer 27

Anterograde: cannot rmb things after onset of amnesia Retrograde: cannot rmb things before onset of amnesia - events closer to time of onset face more risk of being forgotten - more severe for episodic than semantic memory

Question 28

Illustrate the role of the hippocampus in spatial memory using the Morris water maze experiment.

Answer 28

Mice were made to crawl around the edge of a pool The researcher will help and show him where the platform is at After a few repetitions, rat learnt where platform is --> shows spatial memory

Question 29

By measuring the brain activity of single cells in rats with no hippocampal damage and those with it, what can be said about the role of the hippocampus in spatial memory?

Answer 29

Those with no damage would have a mental map of the pool and where the platform --> shows that learning occurred. however, those with damage would not have such a mental map because learning is impaired in them, they cannot form any associations

Question 30

By measuring the brain activities of place cells and grid cells in rats, what can be said about the role of the hippocampus in spatial memory?

Answer 30

Place cells: Cells will be active as long as rat passes by that area. Different cells respond to different locations in space. Concentrated in an area. Grid cells: Just like place cells, but areas are regularly spaced. Different grid cells will have different active locations.

Question 31

List 4 other regions involved in memory and what does damage in these areas entail?

Answer 31

Parietal frontal lobe - inability to link one memory to another Amygdala - deficit in fear memories Medial prefrontal cortex - deficits in learning about rewards and punishments Anterior temporal lobe - damage leads to semantic dementia

Question 32

Distinguish between sensitization and habituation

Answer 32

Sensi --> after a strong stimulus, a subsequent mild stimulus evokes a strong reflex Habit --> after a mild stimulus, a subsequent mild stimulus evokes a weaker reflex

Question 33

Describe the single-cell mechanism of habituation in invertebrates (eg poke siphon).

Answer 33

1. Siphon is poked 2. Sensory neuron senses poke and transmits information to motor neuron 3. Motor neuron retracts gill 4. When habituation occurs, at the synapse, there will be decreased release of neurotransmitters. 5. After habituation, there will be no change in number of action potentials after a stimulation. Sensory neuron still gives a full, normal response to stimulation; it merely fails to excite the motor neuron as much as before.

Question 34

Describe the single-cell mechanism of sensitization in invertebrates.

Answer 34

1. pokes siphon 2. sensory neuron sends a branch to serotonergic neuron (5-HT). 3. serotonic neuron releases serotonin near synapse. 4. serotonin blocks K+ channels in membrane of these neurons. 5. membrane slightly more depolarized 6. presynaptic neuron releases neurotransmitters for longer than usual. 7. repeating this process leads to synthesis of new proteins that produce long-term sensitization

Question 35

What is long-term potentiation?

Answer 35

increased strength of an individual synapse for a period of time

Question 36

List 3 basic properties of LTP.

Answer 36

1. Specificity --> if some of the synapses have been highly active, while others are not, only active synapses will be strengthened. 2. Cooperativity: Nearly simultaneous stimulation by 2 or more axons produce LTP much more strongly than having repeated stimulation by just 1 axon. 3. Associativity: Pairing weak input with strong input enhances later response to weak input.

Question 37

The biochemical mechanism of LTP occurs in the _________.

Answer 37

hippocampus

Question 38

AMPA and NMDA are ______ receptors (2 words)

Answer 38

ionotropic glutamate

Question 39

What does AMPA do during LTP?

Answer 39

Glutamate binds to AMPA receptors, which are excited by glutamate. This binding directly opens Na+ channels, which enter and cell gets depolarized.

Question 40

Describe the role of NMDA receptors during LTP.

Answer 40

Its response to glutamate depends on the degree of polarization across the membrane. At resting potential, magnesium ions blocks channels from opening. Mg is attracted to negative inside part of cell, but does not fit thru channel. as a positive ion, it wishes to enter the cell as the inside of the cell is more negative. but the pore is too small, so Mg is stuck and nothing can enter as the pore is blocked. NMDA channel then permits ions to flow through it only if Mg leaves, so it depolarizes the membrane, hence reducing the negative charge that attracts Mg.

Question 41

Drugs that block NMDA receptors prevent the establishment of LTP but not its maintenance. T/F

Answer 41

True. NMDA receptors lead to increase in AMPA receptors. Plasticity --> increase in no of receptors in postsynaptic cells. Once you establish plasticity, you don't need NMDA anymore. AMPA is already there.

Question 42

List 3 ways that LTP can do to increase synaptic strength.

Answer 42

1) increase synaptic vesicles in presynaptic cell 2) increase receptors in postsynaptic cell. 3) form new synapses