Chapter 13: The Biology of Learning and Memory

Question 1

Classical Conditioning

Answer 1

-pairing two stimuli changes the response to one of them
-Pavlov’s dog
CS+UCS=UCR (initially)
Bell + Meat = Salivation
CS -> CR
Bell -> Salivation

Question 2

Operant/Instrumental Conditioning

Answer 2

-individual’s response leads to reinforcement (increases future probability of response) or punishment (decreases frequency of response)

Question 3

describe Lashley’s search for the engram

Answer 3

• Lashley reasoned that if learning depends on new or strengthened connections between 2 brain areas a knife cut somewhere in the brain should interrupt that connection and abolish learned response
• no knife cut significantly impaired learning
• also found lesions impaired performance but deficit depended more on amount of damage than location

Question 4

engram

Answer 4

• physical representation of what has been learned

ex) connection between 2 brain areas

Question 5

Lashley’s 2 principles

Answer 5

equipotentially- all parts of cortex contribute equally to complex behaviours such as learning and any part of the cortex can substitute for any other
mass action- cortex works better as a whole and more cortex is better

Question 6

2 Unnecessary assumptions for Lashley’s findings

Answer 6

1) cerebral cortex or only place to search for engram

2) all kind of memory are physiologically the same

Question 7

Richard Thompson

Answer 7

• studied classical conditioning of eyelid response in rabbits
• LIP (lateral interpositus nucleus) essential for learning
• when LIP was suppressed learning had no effects

Question 8

characteristics of short-term memory

Answer 8

• maximum capacity
• depends on rehearsal
• forget something=lost forever
• emotionally significant memories form quicker

Question 9

characteristics of long-term

Answer 9

• vast difficulties to estimate capacity
• can recall long term memories you haven’t thought about in years
• hint can help reconstruct something you thought you forgot

Question 10

characteristics of working memory

Answer 10

• way we store info while we are working with it
• test=delayed response task
• older people have impairments of working memory due to changes in prefrontal cortex

Question 11

describe the theories of the function of the hippocampus in declarative memory, spatial memory, context learning, and consolidation

Answer 11

-

Question 12

Declarative memory

Answer 12

• hippocampus is critical for declarative memory (especially episodic)
• hippocampal damage impairs delayed matching and nonmatching to sample task (remembering object that was present in an occasion)

Question 13

Spatial Memory

Answer 13

• when people perform spatial tasks fMRI results show enhanced activity in hippocampus (visualizing a route from one place to another)
• MRI scans showed taxi drivers have larger than average posterior hippocampus (directly proportional to length of time as taxi driver)
• shows growth of hippocampus in response to spatial learning activities
• maze activities- people/rats with damage have trouble remembering where they have already been
• species comparisons show link between hippocampus and spatial memory

Question 14

Contextual memory

Answer 14

Hippcampus-important for remembering details and includes lots of detail, as time passes memory becomes less detailed and more dependent on cerebral cortex

Question 15

Consolidation

Answer 15

• small to moderate amounts of cortisol activate amygdala and hippocampus where they enhance storage and consolidation of recent experiences
• amygdala in turn stimulates hippocampus and cerebral cortex (both important for memory storage)
• prolonged stress (increase cortisol) impairs memory
• consolidation can be fast or slow and depends on more than time necessary to synthesize new proteins

Question 16

causes of Korsakoff’s syndrome

Answer 16

Cause-

• brain damages caused by prolonged thiamine deficiency
• chronic alcoholic
• deficiency leads to loss of shrinkage or neurons in brain

Question 17

Most affected brain area in Korsakoff’s syndrome

Answer 17

-most affected area=dorsomedial thalamus

Question 18

Symptoms of Korsakoff’s syndrome

Answer 18

• apathy, confusion, memory loss

- distinctive symptom=confabulation (mainly for episodic memory questions)

Question 19

Alzheimer’s Disease

Answer 19

• better procedural than declarative memory
• memory and alertness vary substantially suggesting problems results from malfunctioning neurons rather than neuron death
• gradually progresses to more serious memory loss, confusion, depression, restlessness, hallucinations, delusions, sleeplessness, loss of appetite

Question 20

Genetic link to Alzheimer’s

Answer 20

• gene on chromosome 21 linked with Alzheimer’s

- genes to not completely control

Question 21

Early onset Alzheimer’s damage

Answer 21

• causes protein Amyloid-B to build up inside and outside neurons
• damage varies but net effect=damage to dendritic spine , decrease synaptic input and decreased plasticity
• damage from amyloid clusters into plaques
• plaque accumulate- in cerebral cortex, hippocampus and other areas atrophy

Question 22

Tau protein and Alzheimer’s

Answer 22

-becomes altered with more phosphate groups causing them not to be able to bind with usual targets within axons and results in spreading to cell body and dendrites=magnifies damage

Question 23

other brain areas that contribute to various aspects of memory

Answer 23

• gradual learning depends on basal ganglia (implicit or abit learning)
  ex) what a basketball player on another team is most likely to do in a situation so you can guard better

Question 24

Basal ganglia contribute to memory

Answer 24

-important for procedural memory

Question 25

Parietal lobe damage and memory

Answer 25

-process of associating one piece with another is impaired

Question 26

damage to anterior and inferior temporal lobe and memory

Answer 26

-semantic dementia (trouble remembering specific words)

Question 27

mechanisms of habituation and sensitization in Aplysia

Answer 27

-marine invertebrate related to common slug that has larger and fewer neurons that are easier to study

Question 28

habituation Aplysia

Answer 28

• decrease in response to a stimulus that is presented repeatedly accompanied by no other change in other stimuli
  ex) repeated stimulation of aplysia gills with brief jet of seawater it withdraws at first but after multiple reps it stops responding
• > not due to muscle fatigue
• > not due to change in sensory neuron
  conclusion: habituation depends on change in synapse between sensory neuron and motor neuron

Question 29

sensitization Aplysia

Answer 29

• increase in response to mild stimuli as results of exposure to more intense stimuli
  ex) strong stimulus almost anywhere on Aplysia skin intensifies a later withdraw/response to touch
• how this happens (p. 412)

Question 30

describe the characteristics of long-term potentiation (LTP)

Answer 30

• 1+ axons connected to dendrite bombard it with rapid series of stimuli
• burst of intense stimulation leaves some of the synapses potentiated (more responsive to new input of same type) for minutes, days, weeks

Question 31

Properties of LTP

Answer 31

1) Specificity- only active cells become strengthened
2) Cooperativity- nearly simultaneous stimulation 2+ axons produces LTP much more strongly than does repeated stimulation by 1 axon
3) Associativity- pairing weak input with strong input enhances later response to weak input

Question 32

LTD (long term depression)

Answer 32

• prolonged decrease in response at synapse occurs for axons that have been less active than others
• 1 synapse strengthens another weakens

Question 33

roles of AMPA and NMDA receptors in LTP

Answer 33

• entry of Ca2+=key to maintaining LTP

- maintaining of LTP also depends on CaMKII, CREB, BDNF forming

Question 34

AMPA Receptor

Answer 34

• excited by glutamate and AMPA

- Na+ channels opened by receptor

Question 35

NMDA receptor

Answer 35

• ordinarily excited by glutamate but can respond to drug NMDA
• depends on degree of polarization across the membrane NMDA channel opens only if Mg2+ leaves (depolarize membrane decreases negative charge that attracts it)

Question 36

AMPA and NMDA receptors

Answer 36

-ionotropic receptors (stimulated open a channel to let ions enter post-synaptic cell)

Question 37

Final outcome varies including

Answer 37

• dendrite builds more AMPA receptors or moves old ones to better positions
• dendrite may make more branches and spines thus forming additional synapses with same axon
• phosphate groups attach to certain AMPA receptors to make them more responsive than before
• neurons make more NMDA receptors