4.3

Question 1

Neuroplasticity

Answer 1

the ability of the brain to form and reorganize synaptic connections, especially in response to learning or experience or following injury

Question 2

When does neuroplasticity occur?

Answer 2

during development and throughout life and can lead to lasting changes in the structure and function of brain circuitry underlying behavior

Question 3

Steps of neuroplasticity

Answer 3

1. Induction of cell differentiation
2. Neuron generation and apoptosis
3. Neuronal guidance (how neurons hit targets)
4. Synapse formation

Question 4

Neuroplasticity during early development

Answer 4

As the brain and spinal cord develop, neurons are generated at an astounding rate = neurogenesis
Neurons grow as the growth cone of an axon is attracted or repelled and new synapses form.
The fetal brain grows and synapses proliferate. After the baby is born and begins to grow, some of the synapses are no longer needed.

Question 5

Synaptic pruning

Answer 5

the removal of extra synapses

Question 6

Neuroplasticity beyond early development is called

Answer 6

Synapse modification

Question 7

Types of synapse modification

Answer 7

Long term potentation
Long term depression

Question 8

Long term potentation

Answer 8

Results in well-established connections
- repeated exposure to a stimulus results in increased level of activity at that synapse
- example: improved speed in motor learning
Receptors moved from within the cell to synaptic surface - stronger signal

Question 9

Long term depression

Answer 9

Results in poor connectivity, potentially cell death
- repeated or lack of exposure to a stimulus results in decreased level of activity at that synapse
- example: motor learning of the cerebellum, suppressing unwanted movement
Receptors endocytosed - weaker signal

Question 10

Neuroplasticity in the mature brain: healing and learning

Answer 10

Both require a change in neural connections
Neurogenesis is rare and early childhood, but gliogenesis persists throughout the lifespan

Question 11

Neuroplasticity in the mature brain: healing after CNS injury

Answer 11

Often mediated by glial cells
- salvage and strengthen surviving neurons
Facilitate new axon: dendritic connections
Spontaneous recovery involves:
- neurite regrowth
- angiogenesis
- synaptogenesis

Question 12

Learning and neuroplasticity: experience dependent platicity

Answer 12

Maladaptive prevents recovery
- learned nonuse
Adaptive promotes recovery
- focused training to regain use of hand and maintain control in the proper cerebral hemisphere

Question 13

Adaptive therapy

Answer 13

increases activity in brain tissue surrounding damaged area, results in decreased activity in the opposite hemisphere

Question 14

How does the brain adapt and reorganize in response to activity?

Answer 14

1. Synaptogenesis
2. White matter changes (tracks of new synapses)
3. Altered gene expression

LTP is associated with skill acquisition. LDT can lead to microglial synaptic pruning.

Question 15

4 components of memory

Answer 15

1. Acquisition
2. Consolidation
3. Storage
4. Retrieval (recall)

Question 16

Sensory or immediate memory

Answer 16

Lasts no mare than a few seconds
Modality specific and not dependent on attention.
However, attention is required to encode sensory memories into short term memories.

Question 17

Attention

Answer 17

Moves sensory input to short term memory as memories are encoded
- stimulus and goal driven
Involves frontal lobe for sustained attention.
Also involves parietal lobe, thalamus, and visual areas.

Question 18

Short term memory

Answer 18

Lasts seconds to minutes; 4-7 pieces of info
Attention to sensory input –> short term memory
Enhanced with effort
- chunking
- rehearsing
* repeat, organize, contextualize

Question 19

Working memory

Answer 19

Short term memories are dynamically organized and manipulated.
Long term memories are retrieved.
Two subsystems: visual and auditory
Prefrontal cortex

Question 20

Long term memory

Answer 20

Permanent
Large amounts of information stored for prolonged periods
- requires time to encode short term memories into long term memories
Consolidation often occurs during REM sleep
LTP: the process of rehearsing as memories move from short to long term memory, new synapses are formed.
Synaptic consolidation –> systemic consolidation

Question 21

Types of long term memory

Answer 21

Declarative/explicit
- facts and events
Nondeclarative/implicit
- procedures and responses

Question 22

Declarative/explicit memory

Answer 22

To form long term declarative memories, the hippocampus must be intact.
Damage to the medial temporal lobe results in the inability to form long term memories.
Semantic (facts) and episodic (events)
Loss of declarative memory = amnesia
Semantic: lateral and anterior temporal cortex, prefrontal cortex
Episodic: hippocampus, medial temporal lobe, neocortex

Question 23

Nondeclarative/implicit

Answer 23

Procedures and responses
Do not require conscious thought
Basal ganglia and cerebellum
Reinforced by
- procedures
- priming
- associative memory: direct associations are made between two events
* classical and operant learning
- nonassociative learning
* habituation: learn to ignore
* sensitization: increased response following repeated stimulus

Question 24

Forgetting

Answer 24

Retrograde amnesia: before injury
Anterograde: after injury

Question 25

Anterograde amnesia

Answer 25

Typical of MTL lesions
Can be seen in concussion

Question 26

Passive and active forgetting

Answer 26

Passive:
- loss of context cues
- similar memories interfere
- trace decay

Active:
- interference based
- motivation based
- retrieval induced
- intrinsic

Question 27

3 subcategories of nondeclarative memory

Answer 27

Task performance
Behavior
Response

Question 28

Priming

Answer 28

Perceptual ID of words, objects, and other stimuli

Question 29

Nonassociative learning

Answer 29

Involves a change in the strength of a response to a single stimulus, resulting from repeated exposure to that stimulus

Question 30

Habituation

Answer 30

Occurs after repeated exposure to ignore a stimulus that is neither beneficial nor harmful in its environment

Question 31

Sensitization

Answer 31

Progressive increase of a response following repeated administrations of a stimulus

Question 32

Compare working and short term memory

Answer 32

Working memory handles information that enters from sensory memory and recently recalled long-term stores. Working memory is bidirectional, serving as an input and output device, for holding and processing of new and already stored information.