Learning & Memory

Question 1

key functions of hippocampus

Answer 1

• Learning
• Memory formation and retrieval
• Site of adult neurogenesis

Question 2

learning vs. memory

Answer 2

• Learning:
• • Acquisition of knowledge or skills through experience
• • The storage process; creation of memories
• Memory:
• • Information that is stored (ex. Memory of your grandma)
• • The structure that stores the information (e.g. the strength of synapses in a particular part of the brain)

Question 3

Patient HM

Answer 3

• Suffered intractable epilepsy, suffering severe seizures that were resistant to the then available anticonvulsive treatments
• Electroencephalogram indicated that the origin of the seizures was the hippocampus of the medial temporal lobe
• Surgical management considered and undertaken

Question 4

Results of Patient HM’s surgery

Answer 4

• Successful in reducing seizures
• IQ increased
  Able to learn new motor tasks with practice
• Memory problems emerged – severe anterograde amnesia (unable to form new memories)

Question 5

Morris Water Maze - influence of hippocampal lesion

Answer 5

Hippocampal lesion causes increased path length (over control group and other types of lesions) -> significant impairments in learning and memory

Question 6

Rat stress, fear, and learning experiment: basics

Answer 6

• rats put into maze or open field
• fear/anxiety measured (time spent frozen/unmoving, and defecation rate)
• Categorized rats based on consistency in response as either High anxiety (HA) rats or Low anxiety (LA) rats

Question 7

Rat stress, fear, and learning experiment: Morris water maze

Answer 7

• HA rats took longer to find platform that LA rats

- HA rats circled on the outside more than LA rats (who ventured into the middle)

Question 8

Rat stress, fear, and learning experiment: plasma corticosterone levels and mineraloid receptors

Answer 8

• In HA rats, higher levels of plasma corticosterone

- In HA rats, fewer MR receptors, more free-floating glucocorticoids that could bind to GR receptors

Question 9

Barnes maze

Answer 9

• measures Spatial Learning and Memory

- Round table with holes around edges, only 1 hole leads to escape box, rat placed in middle of table

Question 10

advantages/disadvantages of Morris vs. Barnes

Answer 10

• Morris is much more stressful – rats don’t usually go in water
• Barnes assesses perimeter, which rats naturally go to
• Morris has more variables to control/monitor (ie. Water temperature)

Question 11

Memory Retention and Extinction: stromatopod/crustacean example

Answer 11

• Males and females share nest cavity for ~2 days before breeding; intruders to area are repelled
• After mating, male leaves in search of a new mate, while females guard their offspring for 4 weeks, after which the brood/offspring leave
• Question: will males remember their mate?
• • YES! For 2 weeks, they can recognize and show less aggression to their former mate

Question 12

Memory vs. perseveration - what is perseveration?

Answer 12

• Repetition of a response despite the absence/cessation of the
  stimulus.
• Example: Foraging for food

Question 13

2 ways to learn

Answer 13

• genetics/fixed responses

- learning/experiential responses

Question 14

model for evolution of learning: when would natural selection favour each type of learning? (cost-benefit perspective)

Answer 14

• Under conditions where environment rarely changes AND conditions where environment constantly changes, genetics is more beneficial than learning
• In the middle of the 2 extremes, learning is most beneficial

Question 15

assumptions of the model for evolution of learning (when each type of learning is favoured)

Answer 15

• Cost (even very small) associated with learning (ex. Energy output)
• The ability to learn is a trait that has an underlying genetic basis

Question 16

what types of things do animals learn about?

Answer 16

• predators: which animals are predators and which ones are prey
• mates: associating cues with possible mating opportunities
• aggression
• environment: food sources

Question 17

role of learning in conservation biology

Answer 17

• reintroduction programs where endangered species are raised in captivity have had mixed success
• WHY? being raised in an environment that has higher contact with humans and less contact with potential predators gives them less of a chance to learn about their survival (higher rates of predation once released)
• Solution: Present learning opportunities
  while endangered species is being raised
  in captivity (ex. Hellbenders study)

Question 18

Conservation biology: Hellbenders (aquatic salamanders)

Answer 18

• have innate fear response to alarm chemical/mucus released by other hellbenders (In nature: other hellbenders produce the chemical in response to predators)
• Group 1: pair alarm chemical with the scent of a brown trout (predator)
• Group 2: pair alarm chemical with water
• Result: group 1 showed more anti-predator behaviour to the trout predator scent

Question 19

is all learning the same?

Answer 19

NO! it’s environment and species dependent