Learning and memory in mammals

Question 1

Working memory

Answer 1

Limited capacity. Temporarily holds information for processing
Reasoning and guiding decision making behaviour
Allows information to be updated/manipulated (STM)
Deleted after use (no retrieval)

Question 2

Rodent WM test

Answer 2

8 arm radial maze task
Each arm contains food
Working memory used to remember which arm already used
Memory reset for the next task

Question 3

STM and LTM

Answer 3

STM lasts milliseconds to minutes
Information not manipulated
Limited capacity
Selectively transferred to LTM

LTM lasts days to years
Unlimited capacity

Question 4

Non-associative implicit memory

Answer 4

Learning about one type of stimulus
Habituation (desensitisation) due to repeated exposure of non-relevant stimulus
Sensitisation is enhanced response to key stimulus

Question 5

Associative implicit memory

Answer 5

Pavlovian (classical) conditioning is learning important of predictor stimulus

Operant conditioning (trial and error). Behaviour paired with positive reinforcer or negative stimuli

Question 6

Operations of explicit learning

Answer 6

Encoding. Relevant information linked to established memory
Storage (memory retained over time)
Consolidation. Temporary and labile information becomes more stable. Gene expression, protein synthesis and synaptic changes
Retrieval of stored information
Re-consolidation (can be slightly altered)

Question 7

Patient H.M

Answer 7

Uncontrollable temporal lobe epilepsy
Temporal lobe removed surgically (includes hippocampus, amygdala and associated cortex)
Working and semantic memory intact. No retrograde amnesia
Anterograde amnesia. New STM not converted to LTM (last minutes)

Question 8

Areas of brain in learning

Answer 8

Neocortex for storage of LTM
Prefrontal cortex for executive function and working memory
Parietal lobe for navigation
Cerebellum for motor memory
Occipital lobe for visual processing
Temporal lobe for memory encoding /retrieval (hippocampus) and emotional memory (amygdala)

Question 9

Morris water maze

Answer 9

Animal place in pool with external visual cues
Hidden platform to allow animal to sit
Acquisition phase is time to find platform (latency) and length of swim path
Platform removed and animal should be where platform was if memory has formed
Impaired in rats with hippocampal lesion and mice with beta-amyloid

Question 10

Memory function of the hippocampus

Answer 10

Lesion in rodents impairs complex association learning, spatial learning and memory consolidation
Processes new memories and temporarily stores prior to permanent storage in the cortex
Converts STMs to LTMs