Week 6: Learning and Memory

Question 1

Learning

Answer 1

Permanent change in behavior as the result of experience; change in brain structure and/or function

Question 2

Neuroplasticity

Answer 2

Physical change in brain due to experience; required for learning; involved in any event that causes change

Question 3

Sequence of events in learning

Answer 3

Stimulus -> neuronal activity (selective) -> intracellular signaling pathways (events to change) -> gene expression -> protein expression -> structural/functional changes

Question 4

Types of changes in the brain

Answer 4

Neuronal structure, grey or white matter, synapse strength. All can be identified using neuroimaging (usually MRI)

Question 5

Changes in neurons

Answer 5

Structure is changed, not amount. Ex: dendritic arborization (growth of dendrites, thus more synapses)

Question 6

Grey matter change

Answer 6

Dendritic expansion or change to vasculature (supply system to neurons)

Question 7

Synapse strength change

Answer 7

Key to learning; strength of connection between various neurons; improvement of cell communication

Question 8

Hebb’s Postulate (1950)

Answer 8

Activating a synapse repeatedly will change it and strengthen it

Question 9

Bliss and Lomb synapse activation study

Answer 9

Repeatedly activated one axon of one neuron in the hippocampus at a rate of 100 times per second. Found a strengthening of the stimulated neuron. Supported Hebb’s Postulate

Question 10

Long-term Potentiation (LTP)

Answer 10

Long-term increase in ability for cell A to activate cell B; larger excitatory post-synaptic potential (EPSP) in cell B

Question 11

Measuring LTP

Answer 11

Looking at field EPSPs (the response of lots of neurons). After stimulation, there is a spike in PTP (post-tetanic potentiation), and LTP outlasts the PTP spike. Used to measure learning, post-synaptic LTP is the most commonly used

Question 12

Use of LTP in learning

Answer 12

Correlated with learning in many models; fundamental change mechanism across the brain that modifies behavior

Question 13

Long-term Depression (LTD)

Answer 13

Long-term weakening in synaptic strength, induced by prolonged weak stimulus

Question 14

Use of LTD in learning

Answer 14

Tunes the network by eliminating obsolete synapses; acts as a built in reset

Question 15

Rate remapping

Answer 15

Changes in neuron firing rate
Ex: Cell A fires faster than it did before

Question 16

Population remapping

Answer 16

Changes in neuron firing potential
Ex: Cell C fires in response to cell A, where it didn’t before

Question 17

Use of animals in neuronal learning study

Answer 17

Animals are primarily used due to ethical concerns. Studying learning at a neuronal level induces great damage to the brain.

Question 18

London Taxi Driver Study

Answer 18

Argument: learning massive amounts of information should change the brain structure
Method: examining the cortical mass of those who passed the London taxi driver exam and those who did not. To pass you must memorize a massive amount of spatial information
Findings: Larger grey matter amount in those who passed. Increase in posterior hippocampus (spatial info) and decrease in anterior hippocampus (anxiety and stress responses, etc.)
Argument SUPPORTED

Question 19

Music training age study

Answer 19

Argument: long-lasting change should occur, and earlier age of inception should show more change
Method: Correlative observation of musicians who started playing an instrument at various ages. Examining functional differences and cortical response to activity/training
Findings: Those who started at a younger age have a greater response. Changes were specifically seen in the somatosensory cortex
Argument SUPPORTED

Question 20

Change in gene expression

Answer 20

Thousands of genes can be changed during the learning process. Aside from neuronal/structure change, gene expression change is likely the driving factor in learning

Question 21

Memory

Answer 21

Process of information being stored, consolidated, and retrieved. Reconstructive and innacurate

Question 22

Reconstructive-ness of memory

Answer 22

Influenced by current goals, knowledge, expectations and schemas

Question 23

Arousing vs. everyday memories

Answer 23

Arousing memories have a higher level of confidence, i.e we believe we remember them better. However, they show the same level of inaccuracy and forgetting as normal memories

Question 24

Intervening events vs. memory

Answer 24

Intervening events can alter existing memories or create false memories

Question 25

Memory trace/engram theory

Answer 25

Proposes memories are mapped onto small subsets of cells in the brain. When retrieving memories, similar subgroups of cells are activated (not the exact subgroup). Cells within memory subgroups are interconnected with other subgroups (suggests activation of similar memories together)

Question 26

Winner-take-all model

Answer 26

Competitive model of cell selection for engram groups. The more excitable calls at the time of the experience will be put into the memory trace.

Question 27

Testing the winner-take-all model

Answer 27

Method: Performed in rodents. Manipulated CREB amount in cells to make certain cells more active during learning. After learning phase, these high CREB cells were eliminated. Findings: after deletion of high CREB cells, the rodents experienced memory loss. Supports winner-take-all model, suggests active cells (those high in CREB) were made part of the memory trace

Question 28

CREB

Answer 28

cyclic AMP-response element binding protein, affects capacity for change during an event; used to test winner-take-all model

Question 29

Forming many memories at once

Answer 29

Memories formed close in time are attributed to the same excitable/plastic cells, and are likely to have overlapping cell populations. Changing one memory may affect another that has a similar population.

Question 30

Testing multiple memory formation

Answer 30

Method: Studied memories formed close in time vs. not close in time. Conditioned fear response to first memory, but not second. Findings: fear response transferred/generalized between temporally-linked memories, but not the separate memories Suggests memories formed close in time share similar cell traces due to the same cells being active during encoding

Question 31

Memory storage

Answer 31

Tested by Lashley: no one solid place where memories are stored in the brain. Distributed across all areas. Removal of any brain area affected memory

Question 32

Issues with Lashley study of memory storage

Answer 32

Only focused on cortical area, not subcortical structures. Only looked at one type of learning (maze learning), not any other types of learning/memory

Question 33

Role of Hippocampus in memory

Answer 33

Acts as the gateway to declarative memory storage AND plays a role in recall of detail rich episodic memory. Not where memories are stored (misconception).

Question 34

Patient HM

Answer 34

Hippocampus removed. Saw drastic anterograde amnesia. Could not form new memories, could hold past memories. Suggests hippocampus important in creation of new memories but not storage of old memories.

Question 35

Standard Memory Consolidation Theory

Answer 35

Recent memories involve strong connection between the hippocampus and the cortex. As the memory ages the connection weakens and is no longer dependent on the hippocampus

Question 36

Multiple trace theory

Answer 36

Argues the hippocampus creates new memory traces with each recall of a memory. What gets put back is not always what was taken out. Suggests hippocampus is involved in memory creation and memory storage specifically for detail-rich episodic memory

Question 37

Issues with Standard Memory Consolidation Theory

Answer 37

Case studies other than HM show damage of old/remote memories with hippocampal damage as well as anterograde amnesia. Suggests hippocampus is also involved in memory storage

Question 38

Effect of memory type on storage location

Answer 38

Different memory types are stored in different brain areas. Ex: non-declarative memories are stored differently than declarative

Question 39

Brain area associated with recognition

Answer 39

Perirhinal cortex (tested in rodents)

Question 40

Can you improve memory?

Answer 40

Yes, in theory you could activate the cells upon learning. This has been tested via electrode and TMS, and only subtle results have been found

Question 41

Can you erase memories?

Answer 41

Yes, theoretically you should be able to kill the neurons that hold the memory trace. Issues: you can't know which neurons hold the memory and they may be involved in other memories or brain functions

Question 42

Can you create false memories?

Answer 42

Yes. Tested by activating neurons that are part of a safe memory trace during an unsafe event. Found that fear was present when returned to the context of the first safe memory. Supports that manipulating cells within a trace can change the memory

Question 43

Modifying memory to treat PTSD

Answer 43

Aversive memories are recalled while fear responses are blocked using beta-andregernic receptor-blockers. Found that repeated treatments like this can reduce the PTSD responses related to specific memories

Question 44

Benefits of memory modification

Answer 44

Removing negative associations with memories can assist processing, can improve quality of life, and can in some cases improve memory

Question 45

Anterograde amnesia

Answer 45

Lack of ability to form new memories after the traumatic incident to the brain

Question 46

Retrograde amnesia

Answer 46

Inability to remember memories that occurred prior to the traumatic incident/lesion to the brain

Question 47

Declarative memory

Answer 47

A fact about the world or yourself that you can objectively tell someone else. Subsets: episodic and semantic

Question 48

Episodic memory

Answer 48

Clear memories about yourself or your life; facts about yourself or your life that you can verbally tell someone else. Held in the cortex

Question 49

Semantic memory

Answer 49

Facts about the world that you have learned and can verbally express to someone else. Held in the cortex

Question 50

Non-declarative/procedural memory

Answer 50

Things you know that you cannot verbally express, but you can show that you know. Subsets: skill-learning, priming, and conditioning

Question 51

Skill-learning

Answer 51

Procedural skills that you know how to do, such as movements. Stored in the basal ganglia, cortex, and cerebellum

Question 52

Priming

Answer 52

Subconscious preparation of the brain based on seeing or experiencing a stimulus. Stored in the cortex

Question 53

Conditioning

Answer 53

The pairing of a memory or learned response with a specific stimulus. Stored in the cerebellum