Memory Flashcards
What are the parts that are removed in HM’s brain
amygdala, hippocampi and most of the Parahippocampal gyrus
what are the other regions that are damaged during the surgery
orbito frontal damage (WM) and cerebral atrophy
Explain retrograde and anterograde amnesia
Retrograde amnesia = forget things that happened before the injury
Anterograde amnesia = things that happened after the injury
What are the memory types under LTM
Declarative (events and facts) > episodic (event, experiences) and semantic (facts and knowledge)
Procedural (skills and how to)
What is the situation of HM and the two tests that prove the ability to lean
> retrograde amnesia which recovered through time
Severe anterograde amnesia (declarative memories)
Deficit of remembering declarative memories (how to go home)
Don’t recall the death of his uncle
Can’t learn new words
Damaged WM
> Can learn new skills, but don’t remember learning them (corkin and mirror drawing)
What can we learn from HM and his surgery
medial temporal lobe is vital for memory, especially long-term declarative and anterograde amnesia
brain function is asymmetry
What is the importance of the hippocampus
Learning and consolidating information
relational memory
What are the parts of the Papez’s circuit and importance of it
Mamillary body
Fornix
Anterior Thalamic Nuclei
Cingulate gyrus
Hippocampus
(+amygdala = limbic system)
Important for declarative memories (ATN and hippocampi)
Amygdala = the emotion part of the memory
Explain how is the frontal lobe important
Motor programming and cognitive processes
However, also important for memory retrieval, chronological order of memories and the source of information
confabulation = the bizzare distortion of memories
Explain the parts of the diencephalon
the interbrain
hypothalamus
thalamus
No single area is dedicated to memory. However, damage to
anterior and medial thalamus = amnesia
mammillo-thalamic tract = episodic memories
dorsal nucleus = damage of appropriate memory retrival
midline nuclei = damage of memory retrieval and semantic information
Explain Neurotransmitter exchange, Synaptic Plasticity and LTP
When signals are in the axon of the pre-synaptic neuron = electrical signals
When signals are released to the synaptic cleft = chemical signals
When signals enter the post-synaptic neuron = electrical signals
Synapses have high plasticity. The more they excite each other, the more efficient the communication will be
Hebb’s rule:
Alters the effect of the post-synaptic neuron
If neuron A repeatedly excites neuron B
Changes will take place in both neurons
Neuron B will be easier to excite by neuron A
Experiments show that more post-synaptic gates and more neurotransmitters will be released after learning
Where does LTP take place
Regions in the temporal cortex
Hippocampus
Amygdala
Endorhinal Cortex
Outside of the temporal cortex
V1
M1
thalamus
Other mechanism that affects synaptic plasticity
Long-term depression
Neurotransmitters and synaptic strength will decrease due to the inhibition
Habituation
Excess stimulus = reduce synaptic strength
Sensitisation
Poisonous stimulus = exaggerates synapse response
