Lecture 7 - Learning and Memory

Question 1

What is the history of locating memory in the cortex

Answer 1

• Gall: tell someones personality by looking at bumps on head
• Broca & Wernick: diff parts of cortex may have diff functions
• Karl Lashley: worked with rats whilst they foraged for food, trained on maze then damage parts of the brain.
• Mass action: entire cortex involved in everything
• Equipotentiality: if you remove one part, another part fills in

Question 2

Why did people think memory was localised?

Answer 2

• Ppl worked with patients with marked memory impairments
• They marked softening of temporal lobe and correlated it with memory function

Question 3

Describe Patient HM

Answer 3

• Had epilepsy due to medial temporal lobe and had bilateral surgery to stop seizures
• Lost memory and could not remember anything
• Surgery removed multiple cortexes linked to hypocampal functioning

Question 4

Describe HM’s memory

Answer 4

• Severe Anterograde amnesia - cant form memories after surgery
• Graded Retrograde amnesia - memories before surgery (fine)
• Episodic memory impaired

Question 5

Describe HMs working memory

Answer 5

• Intact working memory
• Normal digit span & normal rate of forgetting
• If rehearsal was not allowed, he could not memorise
• Non-verbal short term memory impaired

Question 6

Describe HMs procedural memory

Answer 6

• Intact, could learn new motor tasks
• Performed mirror task, did not remember doing the task but does better everytime

Question 7

What was HMs declarative vs procedural memory systems

Answer 7

• Semantic memory was still intact
• Evidence for single dissociation

Question 8

What was an animal model of human amnesia

Answer 8

• Recognition memory: runs delays non-match sample task (described below)
• Show monkey object
• Displace object and get a food reward
• Show them new object: displace the novel one to get a reward
• Remove parts/cortex of hippocampus
• Normal monkeys with no lesions performed well
• Hippocampal lesions = okay performance = not much impairment
• Hippocampus + one cortex = worse impairment
• Hippocampus + 2 cortexes = floor level

Question 9

What impairs recognition?

Answer 9

• Perirhinal cortex removal

Question 10

what study looked at the contribution of the perirhinal cortex and hippocampus?

Answer 10

• Rats in container will have new toy
• They will explore the novel toy
• Delay: place familar toy with a new toy, they should explore he new toy as they recognise the other toy
• Lesions given to both areas & when Hippocampus is okay, Perirhinal damaged = explore both equally
• Peririhinal = recognition

Question 11

What happens to the hippocampus in spatial memory?

Answer 11

• lesions lower spatial memory
• Shows same in spatial memory in humans via video games

Question 12

How does the hippocampus change across species?

Answer 12

• Animals that rely on spatial memory to survive e.g squirrel have larger hippocampi
• Taxi drivers have larger hippocampus than bus drivers
• Their posterior hippocampus is larger, and anterior hippocampus is smaller
• Size of hippocampus is correlated with time spent as a taxi driver
• However, although specialised in one area, other parts of brain are impaired as seen by a Rey-Osterrith FIgure (Draw and memorise)

Question 13

What is the Papez Circuit?

Answer 13

• Specific network that links different parts of the brain to process memory
• Any damage to a part of the circuit leads to amnesia