L49 - Learning and memory

Question 1

Define learning and memory?

Answer 1

Learning = acquisition of new information; observed as a change in behavior

Memory = retention of the learned information; categorized based on the duration of its retention

Question 2

2 ways to investigate which brain areas are involved in diff. types of learning and memory?

Answer 2

• Measure neuronal activity in the brain while the subject is performing a particular task
• Examine selective memory deficits in patients with different brain lesions

Question 3

Classify memory types.

Answer 3

Immediate memory (fractions of a second to seconds)

Short-term memory (seconds to minutes)

Long-term memory (days to years)

Question 4

2 outcomes in retention of short-term memories?

Answer 4

1) Consolidation into long-term memories (stable)

2) Lost if information is trivial/ meaningless = forget

Question 5

What drives consolidation of selective memories?

Answer 5

Motivation, reward, or association with pre-existing information

Question 6

Function of Working Memory? Which brain area involved?

Answer 6

one type of short-term memory

• achieve a behavioral goal (e.g. remembering a phone number)
• used in planning

• Depends on frontal lobe especially prefrontal cortex**

Question 7

Name the cognitive test used to test working memory?

Answer 7

Wisconsin card-sorting test

Question 8

Define the 2 types of amnesia following trauma.

Answer 8

• Retrograde amnesia: memory loss for events prior to trauma
• Anterograde amnesia: failure to from new memory after the trauma

Question 9

Define Engram?

Answer 9

physical representation of memory (trace) in brain

= synapses that are activated/formed during memory acquisition

Question 10

How is memory affected if medial temporal lobe is resected?

Answer 10

 Intact perception and cognition

 Problems in memory formation:

• Normal working memory
• Severe anterograde amnesia in all kinds of memory
• Temporary graded retrograde amnesia (intact remote memory)

Question 11

Divide long-term memory into 2 types?

Answer 11

based on whether it requires conscious awareness

1) Explicit (declarative, Requires conscious recall)
a) Episodic
b) Semantic

2) Implicit (nondeclarative)

Question 12

Define the 2 subtypes of explicit memory?

Answer 12

1. Episodic memory (memory for events)
   • Personal experience in a specific spatial and temporal context
2. Semantic memory (memory for facts)
   • General knowledge (word, objects, concepts); not associated with context

Question 13

Compare the plasticity and stability between explicit and implicit memory?

Answer 13

Explicit:

• More flexible, more associations formed
• Easier to form and forgotten, less stable

Question 14

Describe the formation of explicit memory. (4 processes)

Answer 14

1. Encoding (acquire new information and link to existing one)
2. Storage (retain the information in specific cortical areas)
3. Consolidation (transform the newly-stored memory, which is labile and susceptible to disruption, to a more stable one)
4. Retrieval (bring back the different kinds of information from different brain areas)

Question 15

Which brain area is involved in encoding explicit memory?

Answer 15

prefrontal cortex and medial temporal lobe

Question 16

Which brain area is involved in storage of explicit episodic memory?

Answer 16

stored in distinct areas of the cerebral cortex**

where the specific aspect of a concept is processed (e.g. image, sound, movement)

Widely stored, no single area

Question 17

Describe the interconnection between hippocampus and cortex in forming explicit memory?

Answer 17

Hippocampal area @ medial temporal lobe:

• Receive sensory information
• Integrates various sensory information to build up memory
• outflow to association cortices for storage of information

** Repeated retrieval of information between hippocampus and cortices = consolidation of memory **

Question 18

Describe the connection and function of the connection between visual cortex and frontal association cortex?

Answer 18

1. Dorsal stream:
   - Spatial information (e.g. position, motion)
   - To parietal association cortex (also receives somatosensory input)
2. Ventral stream:
   - Information about form (e.g. color, shape) + auditory, somatosensory input
   - To temporal association cortex
   »»> Where semantic information is stored ***

Both parietal, temporal association cortices project to frontal association cortex

Question 19

Where is semantic information stored?

Answer 19

Temporal association area

Question 20

Define the brain region for spatial memory and list the cells involved.

Answer 20

Hippocampus

constitutes a cognitive map for the surrounding environment

Place cells in the hippocampus + grid cells in the entorhinal cortex (which provides input to the hippocampus) are involved

Question 21

Classify implicit memory types?

Answer 21

• Priming
• Procedural memory
• Habit learning
• Non-associative learning
• Associative learning

Question 22

Define ‘priming’ in implicit memory and brain region involved?

Answer 22

Exposure to one stimulus influences the response to a subsequent stimulus unconsciously

Depends on neocortex*** (not medial temporal lobe)

Question 23

Define procedural learning in implicit memory and brain region involved?

Answer 23

Skill learning includes:

a) Visuo-motor skills
b) Perceptual learning

Training and repeated stimulation causes shift from parietal cortex activity to inferior temporal cortex&raquo_space; direct recognition

Not affected by medial temporal lobe or Hippocamus

Question 24

Which patient retain ability for procedural learning: Amnesic patient (e.g. Alzheimer’s) with medial temporal lobe damage or Parkinsons patient?

Answer 24

Procedural learning requires parietal cortex + inferior temporal cortex, doesn’t involve medial temporal lobe or hippocampus

Alzheimer’s retain ability
Parkinson’s lose ability

Question 25

Define habit learning in implicit memory and brain region involved?

Answer 25

Repeated stimulation and tasks form strong association

Depends on the striatum***
,NOT medial temporal lobe

deficit in Parkinson’s disease (PD) but not amnesic (AMN) patients

Question 26

Define non-associative learning and Subtypes in implicit memory and brain region involved?

Answer 26

unconscious change in response to stimulus: includes:

1. Habituation: decrease in response to a non-threatening stimulus (“learning to ignore”)
2. Sensitization: increase in response to different stimuli after an intense or noxious event (startle reflex)

> > > Depends on reflex pathways

Question 27

Define associative learning and Subtypes in implicit memory and brain region involved?

Answer 27

1. Classical conditioning (e.g. fear conditioning): association of two stimuli
   »> response by AMYGDALA
2. Operant conditioning: association of an action and the outcome (behavior is controlled by consequences)
   »> response by CEREBELLUM

Question 28

Describe the pathways involved in fear learning (a type of classical associative learning)?

Answer 28

2 neural pathways relay information (e.g. auditory, somatosensory) from thalamus to amygdala

1. Rapid direct pathway (from somatosensory thalamus to lateral nucleus of amygdala)
2. Slower indirect pathway (e.g. relay from thalamus to auditory cortex/ somatosensory cortex, then to lateral nucelus of amygdala)

Question 29

Summarize the brain regions required for explicit memory?

Answer 29

Semantic
Episodic

Both go to medial temporal lobe
Semantic memory is stored at temporal association area

Question 30

Summarize the brain regions required for implicit memory?

Answer 30

• Associative (classical, operant) = amydgala, cerebellum
• Non-associative (habituation, sensitization) = reflex pathways
• Procedural = Parietal and inferior temporal cortices
• Habit = Striatum
• Priming = neocortex

Question 31

Describe the changes to synapses in Engram?

Answer 31

Experience-dependent change in synaptic strength = synaptic plasticity

Learning Increases synpatic strength (more receptors, structural change), stronger postsynaptic response