LECTURE !0

Question 1

PATIENT HM

Answer 1

Surgical removal of the medial temporal lobes, bilaterally
HM was unable to form new long-term memories
* Retained memories that were formed prior to
surgery in 1953 [Anterograde amneisa]
No change in IQ or language ability
* Indicates impairment is specific to memory, not cognition generally
* Still able to follow a short conversation
* Indicates there must be a type of short term memory that is different from long term memory
* Could still learn some new things! - mostly implicit memories [Indicates there must be some other kind of memory mechanism for non- declarative memories]

Question 2

What We’ve Learned from H.M. & Other
Cases of Amnesia

Answer 2

• Procedural/implicit/skill learning still intact
• Mirror-drawing task: trace the shape in front of you using only the mirrored view of the paper
• Errors (however you want to code that) decreased over time
• Even though he had no conscious memory of doing the task!

Question 3

Spared Skill Learning in Amnesia

Answer 3

• Mirrored word-reading task - Both healthy controls and amnesiacs get better
  at the task over time
• Word-stem task - Participants are given a word-stem and then asked to complete it by choosing endings from a list. Amnesiacs subject to priming effects (More likely to complete the stem with the word they were exposed
  to previously (even if they don’t remember that word))

Question 4

MEMORY SYSTEMS

Answer 4

MEMORIZE ZE SLIDE

Question 5

THREE STAGES OF MEMORY PROCESSING

Answer 5

Encoding
Processing
Retrieval
- Consolidation (facilitated by Medial temporal lobe)

Question 6

Working memory

Answer 6

The ability to hold a limited amount of information actively
* Limited in capacity
* Short term
* magic number 7 +/- 2

Question 7

Extensive damage to the medial
temporal lobe leads to amnesia

Answer 7

including the:
* Hippocampus
* Neighboring areas (parahippocampal,
entorhinal & perirhinal cortices)
* Dentate gyrus
* Subiculum
* Amygdala

Question 8

Neurobiology of Memory

Answer 8

• From there, information enters hippocampus via perforant pathway
• Travels through subfields of hippocampus before exiting:
• Back to entorhinal cortex
• To other brain regions via the fornix
• Other regions -> Entorhinal cortex -> Hippocampus ->
  Entorhinal cortex (again) OR other regions via fornix* Anatomy of hippocampus allows information from many brain regions to converge on entorhinal cortex
• From there, information enters hippocampus via
  perforant pathway
• Travels through subfields of hippocampus before
  exiting:
• Back to entorhinal cortex
• To other brain regions via the fornix
• Other regions -> Entorhinal cortex -> Hippocampus ->
  Entorhinal cortex (again) OR other regions via fornix

Question 9

• Long-term potentiation

Answer 9

The process of connections between neurons becoming stronger and more efficient over time (due to repeated stimulation)

Question 10

• Two types of glutamate receptors

Answer 10

AMPA AND NMDA

Question 11

AMPA

Answer 11

has an excitatory function

Question 12

NMDA

Answer 12

as a magnesium ion that only opens when post-synaptic neuron is already depolarized

Question 13

NMDA receptor activation

Answer 13

• Lets calcium (Ca2+) ions into the cell
• This triggers some intracellular mechanisms that:
  1) In the short term: produce more AMPA receptors in the synapse
  2) In the long term: create whole new synaptic terminals!

Question 14

Working Memory

Answer 14

• Working memory allows us to retain limited amounts of information for a short time while we are actively working on that information
• Patients with hippocampal damage, who have intact working memory but disrupted long-term memory, suggest that working memory and long-term memory rely on different substrates

Question 15

Visuo-spatial pad

Answer 15

Short-term visual information

Question 16

Central Executive

Answer 16

Conscious control of what memory/sensory info is attended to

Question 17

Phonological Loop

Answer 17

Short-term auditory information

Question 18

Dorsolateral prefrontal cortex (DLPFC)

Answer 18

Lesions to DLPFC impairs performance on memory tasks involving short delay

Question 19

Hypothesis

Answer 19

higher frequency activity (gamma band) is related to supporting working memory representations

Question 20

Summary: Brain Systems Involved in Memory

Answer 20

READ THE BOLD TERMS

Question 21

Dorsolateral prefrontal lobe

Answer 21

Involved in working memory

Question 22

Hippocampus

Answer 22

Involved in encoding of episodic and declarative
memory

Question 23

Amygdala

Answer 23

Involved in emotions and emotional learning

Question 23

Inferior temporal cortex

Answer 23

Involved in retrieval