15. LEARNING & MEMORY

Question 1

What are the broad two types of memory?

Answer 1

1. Declarative memory

2. Non-declarative memory

Question 2

What is declarative memory?

Answer 2

• Explicit
• Declarative memory refers to facts & events that can be recalled or retrieved consciously
• These memories are explicitly stored & recalled

Question 3

What is non-declarative memory?

Answer 3

• Implicit
• Non-declarative memory is accquired & can be used unconsciously
• Can affect thoughts & behaviors

Question 4

What are three types of non-declarative memory?

Answer 4

1. PROCEDURAL MEMRY - Striatum
2. SKELETAL MUSCULATURE- Cerebellum
3. EMOTIONAL RESPONSE - Amygdala

Question 5

*What is procedural memory?

Answer 5

• Procedural memory is part of long term memory, involves knowing how to do certain procedures without conscious awareness of previous memories
• Involves the striatum

Question 6

What is associative learning?

Answer 6

• A type of learning where a new response is associated with a particular stimulus
• E.g Pavlov

Question 7

What are the three types of declarative memory?

Answer 7

1. WORKING MEMORY
2. SHORT TERM MEMORY
3. LONG TERM MEMORY

Question 8

What is working memory?

Answer 8

• Type of declarative memory
• Cognitive system with limited capacity
• Temporary storage lasting seconds
• Found in pre-frontal cortex

Question 9

What is short term memory?

Answer 9

• Type of declarative memory
• Can hold information for short amount of time but not modified
• Vulnerable to disruption

Question 10

What is long term memory?

Answer 10

• Type of declarative memory
• unlimited capacity
• Can recall memory after months or years
• Issue is accessibility not availability

Question 11

How can short term memory be converted into long term memory?

Answer 11

• Memory consolidation
• Memory consolidation is a time dependent process where learned experiences can be transferred into the long term memory

Question 12

Describe the pathway of information from the sensory information into long term memory?

Answer 12

Sensory information -> Short term memory or short term memory
- Short term memory -> long term memory

Question 13

What type of memory is found in the pre-frontal cortex?

Answer 13

• Working memory

Question 14

What are the functions of the pre-frontal cortex?

Answer 14

• Decision making
• Problem solving
• Planning
• Self-awareness

Question 15

Describe an experiment showing the importance of the pre-frontal cortex

Answer 15

• In an animal study, where the animal had to remember where the object was located from memory., there was a delay phase
• During this delay phase, the animal was trying to remember where the object was using it’s working memory
• There was increased firing in the pre-frontal cortex showing the importance of the working memory

Question 16

What is an engram?

Answer 16

• Memories are encoded in groups of neurones called engrams

- Engrams are where memories are stored

Question 17

What is the Hebbian theory for memory?

Answer 17

• The Hebbian theory suggests that cell assemblies are formed during learning & memory as a result of the synaptic changes arising from a stimulus
• These cell assemblies can then be modified & strengthened
• Partial activation of the cell assembly, leads to activation of the entire representation

Question 18

Which brain structure is involved in memory consolidation?

Answer 18

• Hippocampus is involved in memory consolidation

Question 19

Which lobe is the hippocampus found in?

Answer 19

• Medial temporal lobe

Question 20

**Describe the flow of sensory information through the medial temporal lobe?

Answer 20

Sensory information -> Para hippocampal/entorhinal areas -> Hippocampus/Medial temporal lobe -> Hypothalamus via the fornix

Question 21

What is amnesia?

Answer 21

• Amnesia refers to the loss of memory and/or the ability to learn

Question 22

What are some causes of amnesia?

Answer 22

• Concussion
• Encephalitis
• Brain tumour
• Chronic alcoholism
• Stroke

Question 23

What are the two types of amnesia?

Answer 23

1. Retrograde amnesia

2. Anterograde amnesia

Question 24

What is retrograde amnesia?

Answer 24

• Retrograde amnesia refers to the inability to recall previous/old memories before the point of trauma

Question 25

What is anterograde amnesia?

Answer 25

- Anterograde amnesia refers to the inability to form & recall new memories after the point of trauma - However long term memory before point of trauma is still in tact

Question 26

What is spatial memory?

Answer 26

- Spatial memory is a type of memory responsible for the recording & recall of information needed for navigation

Question 27

What are place cells?

Answer 27

- Place cells are neurones located in the hippocampus - They are involved in spatial memory - Place cells fire when an animal is in a location - Place cells are neurones which are glutamatergic, so glutamate antagonists can disrupt the process of learning

Question 28

Where are place cells located?

Answer 28

- Place cells are located in the hippocampus | - Neurons involved in spatial memory

Question 29

What are the two models of memory consolidation?

Answer 29

1. Standard model of memory consolidation | 2. Multiple trace model of memory consolidation

Question 30

What is the standard trace model of memory consolidation?

Answer 30

- Sensory information form the neocortex (cerebral cortex) is sent to the hippocampus (medial temporal lobe) for processing - Synaptic systems consolidation: Memories are transferred to different brain regions from the hippocampus, stored in engrams of different regions - After memory consolidation, the hippocampus is no longer needed & doesn't play a role in memory

Question 31

What is the multiple trace model of memory?

Answer 31

- Multiple trace model of memory suggests that even after memories have been transferred to engrams in different regions of the brain, the hippocampus is still involved - Changes to hippocampal activity can modify the memory stores

Question 32

What is synaptic plasticity?

Answer 32

- Both models of memory consolidation involve synaptic plasticity - Synaptic plasticity is a biological process where changes in patterns of synaptic activity lead to changes in synaptic strength

Question 33

**What is the trisynaptic circuit?

Answer 33

- The trisynaptic circuit is the relay of synaptic transmission in the hippocampus/medial temporal lobe

Question 34

**Describe the flow of information in the trisynaptic circuit?

Answer 34

- Entorhinal cortex --> Dentate gyrus via the PERFORMANT PATH - MOSSY FIBRES from the dentate gyrus synapse with pyramidal neurons CA3 of the hippocampus - Axons of CA3 known as SCHAFFER COLLATERALS synapse with CA1 hippocampal region

Question 35

Define long-term potentiation

Answer 35

- Long term potentiation is the process by which repeated patterns of synaptic activity result in the consistent strengthening of a synapse

Question 36

Why does dendritic spine growth occur as a result of long term potentiation?

Answer 36

- Long term potentiation results in increased AMPA expression in the post-synaptic membrane - The membrane increases in size to accommodate the increase in receptors which leads to dendritic spine growth