79 - Memory and Learning

Question 1

Learning

Answer 1

Learning
– A process by which new information is acquired by the nervous system (brain) and adaptive changes in behavior are produced.

Question 2

Memory

Answer 2

Memory
– Encoding, storage, and retrieval of learned information
– Record stored as the interpreted experience
– Ability to forget information that is only temporarily useful
– Involves a wide array of neuronal circuits and a process for activation (recall)
– Stored in some context (codification)
– Cross-referencing – various ‘entry points’, contexts
– Memory trace (engram) - pattern of activity unique to the record (memory)

Question 3

Types of learning

Answer 3

• Associative
• Non-associative (simple)
• Non-associative (complex)

Question 4

What is associative learning?

Answer 4

Learning regarding the relationship between two or more stimuli

Question 5

Two types of associative learning

Answer 5

• Passive

- Operant

Question 6

Passive associative learning

Answer 6

Passive

1) Simple conditioning
2) Temporal relation between stimuli

Question 7

Operant associative learning ***

Answer 7

Operant
1) Primary stimulus is associated with a different reinforcement
stimulus
2) Reinforcement stimulus may be positive or negative (aversive)

Question 8

What is the role of reinforcement in associative learning?

Answer 8

• Generally, time sensitive; will vary with the reinforcing stimuli
• Positive reinforcement will enhance the occurrence of the response
  • e.g. sex, money, cocaine and other abused drugs (positive
  reinforcers, activate the endogenous reward pathways)
• Negative reinforcement; will reduce the occurrence of a particular behavior to avoid an undesirable condition
  • Aversive learning will reduce the occurrence of the response. e.g. disciplining a child

Question 9

Two types of non-associative (simple) learning

Answer 9

• Habituation (tolerance)

- Sensitization

Question 10

Habituation (tolerance)

Answer 10

Diminished response following a repeated stimuli, e.g. lecture

Question 11

Sensitization

Answer 11

Enhancement of a response by the addition of a second strong or noxious stimulus, e.g. loud noise or other noxious stimuli

Question 12

Two types of non-associative (complex) learning

Answer 12

• Imprinting

- Vicarious or latent

Question 13

Imprinting

Answer 13

1) Bonding or behavioral attraction of a young animal to a parent
2) A developmental process that must occur during a ‘critical period’

Question 14

Vicarious or latent

Answer 14

1) Simple experience of familiarity
2) No motivation or reinforcement (reward) necessary
3) Imitation or observation

Question 15

Now onto memory…

Answer 15

Need to memorize categories

Question 16

What are the two qualitative categories of human memory?

Answer 16

• Declarative (explicit)

- Non-declarative (implicit, procedural, motor)

Question 17

Declarative (explicit)

Answer 17

a. Types of information
1) Semantic (facts)
2) Episodic (events)

b. Brain area involved
1) Medial temporal lobe (hippocampus and surrounding structures)
2) Diencephalon (basal forebrain, thalamus)

c. Can be brought to a conscious level and described or examined

Question 18

Non-declarative (implicit, procedural, motor)

Answer 18

a. Skilled movements and habits (motor behavior)
• Striatum, motor cortex, cerebellum, spinal reflex circuits

b. Priming (process of completing a word/picture, i.e. ‘activating’ a memory). when only presented with a portion of the information; based
upon prior experience
• Neocortex

c. Basic associative learning
1) Emotional responses
• Amygdala and limbic circuits
2) Skeletal musculature
• Cerebellum; spinal reflex circuits

d. Non-associative learning
• Complex reflexive pathways

Question 19

Three temporal (time) categories of memory

Answer 19

• Short term
• Working
• Long term

Question 20

Short term memory

Answer 20

seconds – minutes – hours

Question 21

Working memory

Answer 21

− Has short-term nature, but is very different from other forms of shot term memory.
− Process for ‘holding’ information in a useable form for basic cognitive activities
− The contents of WM can be recalled from long-term storage or can represent a recent even that is temporarily held in mind
− To guide behavior and inhibit inappropriate actions
− Limited capacity; easy to distract
− Involved brain regions mature late in developmental stages
− Fragile process: targeted by aging, stress, etc

Question 22

Long term memory

Answer 22

days to years

Question 23

Three domains of memory

Answer 23

• Cognitive
• Psychomotor
• Affective

Domains are NOT mutually exclusive

Question 24

Cognitive domain

Answer 24

To recall, calculate, discuss, analyze, problem solve, etc.

Question 25

Psychomotor domain

Answer 25

To dance, swim, ski, dive, drive a car, ride a bike, etc.

Question 26

Affective domain

Answer 26

To like something or someone, love, appreciate, fear, hate, | worship, etc.

Question 27

Memory processing - three steps

Answer 27

1 - Sensory input 2 - Memory storage 3 - Memory extinction

Question 28

Another name for sensory input

Answer 28

Acquuisition

Question 29

Describe the steps of memory storage and location

Answer 29

a. Consolidation (hippocampus) - while an active process, consolidation seems to require sleep b. Rehearsal and recall c. codification, the context or category in which memory is stored

Question 30

What is memory extinction?

Answer 30

Forgetting

Question 31

Fear memory extinction

Answer 31

AKA repression - Fear memory extinction relies on a network of three structures. - The amygdala stores both conditioning and extinction memories. - CS information enters the amygdala, hippocampus, and prefrontal cortex(PFC). - The PFC integrates CS information with contextual information from the hippocampus in order to determine extinction retrieval. - In the extinction context, the PFC inhibits amygdala output, to reduce fear. - Outside the extinction context, amygdala output is uninhibited.

Question 32

There are five memory systems

Answer 32

``` 1 - Episodic 2 - Semantic 3 - Perceptual representation 4 - Procedural 5 - Working ```

Question 33

Episodic memory system

Answer 33

a. Recollection of events in the context of a particular time and place relative to a person's past experiences b. Medial temporal lobes, especially the hippocampus are critical for acquisition and consolidation of this memory system. The prefrontal cortex/frontal lobes are also involved.

Question 34

What clinical condition is associated with the episodic memory system?

Answer 34

'Source amnesia' - a condition in which the patient retains the ability to learn new facts but cannot recall when or where they were learned • Observed in the elderly, especially in association with frontal lobe dysfunction/pathology • Observed in young children with immature frontal lobes • Associated with 'false memories' in frontal lobe damage

Question 35

Semantic memory system

Answer 35

a. General knowledge of facts and concepts without reference to time and place as to when they were ‘learned’ b. Medial temporal lobes vital for acquisition and consolidation; integrity of anterior and lateral aspects of the temporal lobe, especially in the left hemisphere

Question 36

What clinical condition is associated with the semantic memory system?

Answer 36

Semantic dementia' – seen in elderly patients with a lack of knowledge for the properties of a specific object yet intact episodic memory • Though both episodic and semantic memory are considered 'declarative/explicit' they can be dissociated as evidenced by pathology

Question 37

Perceptual representation memory system

Answer 37

Identification of words and objects based upon their form and structure

Question 38

Perceptual representation contributes to four skills

Answer 38

- Visual work recognition - Auditory recognition - Structural description - Facial recognition

Question 39

Visual work recognition

Answer 39

* Extrastriate visual cortex (form) | * Temporal and frontal cortex (meaning)

Question 40

Auditory recognition

Answer 40

Auditory association cortices, temporal lobe

Question 41

Structural description

Answer 41

* Relation of parts of an object to the entire structure | * Occipitotemporal junction

Question 42

Facial recognition

Answer 42

• Areas of the ventral occipitotemporal cortex are rich in 'face cells' • Though bilateral, the right hemisphere predominately processes the 'face' as a whole while the left hemisphere tends to break it into components • Frontal cortex interprets facial 'emotions' particularly through activity in the amygdala

Question 43

Procedural memory system

Answer 43

a. Skills and behavioral habits, including rules for classification, organizing sequences and grammatical rules b. Corticostriatal projections, basal ganglia, motor cortex and cerebellum, probably spinal cord as well, for some simple reflexive behaviors)

Question 44

Working memory system

Answer 44

Process for 'holding' information in a readily useable fashion for basic cognitive activities such as reasoning, problem-solving, comprehension and evaluation

Question 45

Working memory system consists of three interrelated components

Answer 45

i. Executive component - to coordinate information ii. Phonological loop - involves left temporal and frontal language areas for verbal-type information iii. Visuospatial component - visual association cortex, inferior parietal and inferior prefrontal cortex, particularly of the right hemisphere for visual and spatial information

Question 46

There are three plausible mechanisms of memory formation

Answer 46

- Recurrent circuit - Synaptic plasticity - Synaptogenesis

Question 47

Recurrent circuit

Answer 47

a. Positive feedback system b. Capable of producing persistent neural activity, but for a short term period c. Rapid extinction d. Proposed neural correlate of working memory

Question 48

Synaptic plasticity

Answer 48

Plastic changes that either strengthen or weaken synaptic | transmission

Question 49

Short term plasticity

Answer 49

Short-term plasticity: lasting for a few minutes or less - Synaptic efficacy − habituation − sensitization

Question 50

Long-term plasticity

Answer 50

Long-term plasticity: lasting for hours or more - Long-term potentiation (LTP) - A given stimulus to the afferent pathways of hippocampus, for example, produces a characteristic and reproducible response. Following a strong, sustained stimulus or high frequency stimulus, the response to the previously defined stimulus is greatly enhanced. This enhanced response (potentiation) lasts for a very long period (minutes→ hours inn vitro, and hours --> days in vivo) - Induction mechanisms of some types of LTP are dependent on NMDA receptors - The expression mechanisms of LTP involve both presynaptic and postsynaptic. - As a process for encoding memories, synaptic responses can be suppressed (long-term depression, LTD) or scaled back after LTP.

Question 51

Synaptogenesis

Answer 51

Synaptogenesis - changes in the number of active synapses - Morphological neuronal plasticity - Requires protein synthesis - Synaptogenesis plays a role during development as well as throughout life

Question 52

Modulation of memory systems

Answer 52

There are both intrinsic factors and external impacts on memory processing

Question 53

Intrinsic factors

Answer 53

Intrinsic factors - Developmental stages - Aging - Hormones

Question 54

External impacts (many)

Answer 54

External impacts (many) - Stress - Concussion

Question 55

Amnesia

Answer 55

The inability to recall or form memories

Question 56

Anterograde amnesia

Answer 56

- Inability to form NEW memories - Primarily a defect in consolidation though it could involve acquisition - Hippocampal damage (consolidation of declarative memory) - left hippocampus - verbal information (words, writing) [broad generality] - right hippocampus - nonverbal information (complex visual and auditory patterns) [broad generality] - Affects declarative and not procedural memory - Anesthetic and sedative hypnotics (CNS depressants) may induce an anterograde amnesia (e.g., as in surgery) by an impairment of acquisition and consolidation

Question 57

Retrograde amnesia

Answer 57

Retrograde - Inability to recall previously stored memories - Temporal quality; older memories are more resistant to 'loss' while new more recent memories are more vulnerable - Defect in recall; rarely is the memory trace itself lost

Question 58

Alzheimer's disease

Answer 58

Most common form of cortical dementia in humans

Question 59

Symptoms of Alzheimer's

Answer 59

``` Symptoms include: – aphasia (inability to speak) – apraxia (disordered motor planning) – agnosia (inability to process sensory information like recognize people) – amnesia ```

Question 60

Pathology of Alzheimer's

Answer 60

• Neurofibrillary tangles (tau) & senile plaques (β-amyloid) • Risk factors: age, family history, risk genes (ApoE, APP PS1,2) • Etiology not well understood • Memory impairment associated with neuronal loss in the hippocampus, cortex & basal forebrain (cholinergic) − anterograde amnesia (hippocampal damage) − disease progression → retrograde amnesia (cortex and forebrain)