Biological Basis of Memory

Question 1

What do conditions makes people tend to do poorly in implicit memory?

Give an example of a condition?

Answer 1

Conditions affecting their striatum.

Parkinson’s or Huntington’s disease.

Question 2

What part of the brain is important for declarative memory?

Answer 2

The medial temporal lobe and the hippocampus.

Question 3

What happens in the medial temporal lobe?

Answer 3

The memories change from being STM to LTM, this is called consolidation.

Question 4

What 4 factors is consolidation affected by?

Answer 4

• The depth of stimulus processing.
• Distinctiveness
• Relevance
• Emotionality

Question 5

What do stressful or emotionally exciting experiences increase?

Answer 5

The secretion of adrenaline (aka epinephrine) and cortisol.

Question 6

What area of the brain does cortisol activate?

Answer 6

The amygdala and hippocampus where they increase memory consolidation and storage.

Question 7

What part of the brain does the amygdala stimulate?

What does this do?

Answer 7

The hippocampus and cerebral cortex which increases memory storage.

Question 8

Why does greater processing of negative or threat related information have an evolutionary advantage?

Answer 8

Allows for better avoidance of dangerous situations.

Question 9

How can prolonged stress affect memory?

Answer 9

Impairs memory as it increases large amounts of cortisol.

Question 10

What state is a memory in when it is reactivated?

What is the memory like in this state?

Answer 10

A labile state.

It is fragile or malleable, it can be weakened or altered or strengthened.

Question 11

What brain regions do consolidation and reconsolidation use?

Answer 11

Evidence suggests they rely on the same brain regions and same proteins.

Question 12

How are memories created in the brain?

Answer 12

Due to changes happening at synapses between neurons.

Question 13

When do changes in synapses that create memories occur?

Answer 13

When one or more axons bombard a dendrite with stimulation.

Question 14

What synapses does long term potentiation depend on?

Answer 14

Glutamate synapses. The most prevalent excitatory neurotransmitter in the brain.

Question 15

What 2 types of glutamate are important in long term potentiation?

Answer 15

AMPA and NMDA.

These are 2 ionotropic receptors.

Question 16

Why are AMPA and NMDA call ionotropic receptors?

Answer 16

Because when they are stimulated, they open channels for ions to pass through.

Question 17

What channels does AMPA open?

Answer 17

Sodium channels when stimulated by glutamate

Question 18

What does NMDA’s response to glutamate depend on?

Answer 18

The polarity of the membrane - sodium can come in until it is depolarised.

Question 19

What charge do magnesium ions have?

What are they attracted to?

Answer 19

. Positive

. Negatively charged cells but that are too big to get through NMDA receptors channels, so just sit there blocking it.

Question 20

What action depolarises the membrane?

Why is this?

Answer 20

Repeated glutamate of AMPA receptors.

because the AMPA receptor is letting positively charged Na+ into the cell - making the membrane potential more positive.

Question 21

What does the depolarisation displace?

Answer 21

Magnesium molecules that had been blocking NMDA receptors.

Question 22

Why were the Mg molecules attracted to the cell?

What happens if the cell becomes less negative?

Answer 22

Because the cell was negative, and the Mg molecules are positive.

They are not so strongly attracted and dislodge. This leaves the NMDA channel free for other ions - at which point sodium (Na+) and Calcium (Ca++) come flooding.

Question 23

What protein does calcium activate?

What does this protein begin?

Answer 23

CaMKII.

Begins a series of reactions that leads to the release of a protein called CREB.

Question 24

What protein magnifies the effects of CaMKII and CREB?

Answer 24

BDNF

Question 25

What is the factor that determines which neurons will undergo long term potentiation?

Answer 25

Only those with the highest concentration of CaMKII, CREB and BDNF will undergo long term potentiation.

Question 26

What can changes in the presynaptic neuron cause?

Answer 26

Long term potentiation.

Question 27

Extensive stimulation of a postsynaptic cell causes the release of a retrograde. transmitter that travels back to the presynaptic cell to cause what 4 changes?

Answer 27

• Decrease in action potential threshold.
• Increase neurotransmitter release.
• Expansion of the axons.
• Transmitter release from additional sites.

Question 28

What are the 3 properties in long term potentiation?

Answer 28

1. Specificity
2. Cooperativity
3. Associativity

Question 29

What improves declarative and procedural memory?

Answer 29

Sleep

Question 30

What kind of sleep enhances retention of declarative (mainly episodic) information and non-declarative procedural performance?

Answer 30

Compared with a period of wakefulness of equal length, a period of post learning sleep enhances it.

Question 31

What memories does sleep protect?

When is sleep beneficial for learning?

Answer 31

Newly learned declarative memories from interference.

The beneficial effects of sleep are enhanced if sleep takes place immediately after learning rather than after a delay.

Question 32

What type of learning is sleep deprivation associated with?

What can sleep deprivation cause re memory?

Answer 32

Explicit learning.

Memory problems.

Question 33

What is the simplest explanation for forgetting long term memories?

Answer 33

Decay, it is a passive process.

Question 34

Forgetting: Give a brief overview of interference

Answer 34

• Memories acquired on different occasions interfere with each other.
• The similarity between the memories affects interference.
• Retroactive interference - acting backwards.
• Proactive interference - acting forwards.

Question 35

What are event-related potentials a measure of?

Answer 35

Electroencephalogrpahy (EEG).

Question 36

Give an example of clinical forgetting.

Answer 36

Amnesia