Memory Flashcards
what are the 3 regions of the extra temporal brain that are particularly involved in memory?
- papez’s circuit
- frontal lobes
- diencephalon
when was papez’s circuit founded?
1937?
what did papez propose?
that a specific circuit was devoted to emotional experience and expression
what does the limbic system comprise of?
amygdala and Papez’s circuit
what does the amygdala do?
supports memory for emotionally arousing experiences
what part of the brain is typically involved in classical fear conditioning?
amygdala
where are stress hormones released from?
adrenal glands
release of NT’s accentuates what? where does this happen?
the laying down of the memory so it is a stronger memory
in the amygdala
lesioned amygdala can lead to what?
loss of conditioned fear, and impairment of new fear learning as well as reduced capacity for formation of emotionally laden events
what does papez’s circuit comprise of?
mamillary bodies, fornix, anterior thalamic nuclei, cingulate gyrus and hippocampus
what are the mamillary bodies apart of?
the hypothalamus
what is an efferent pathway?
pathway that is outgoing
what is the order of the closed circuit of papez’s circuit?
hippocampus to the mamillary bodies to the anterior thalamic nuclei, to the mid section of the cingulate cortex
what happens when lesions occur to parts of Papez’s circuit?
declarative memory impairment
how does damage to papez’s circuit often happen?
strokes and tumours
what is the only part of papz’s circuit that resides in the mesial temporal lobes?
the hippocampus
if any part of papez’s circuit is damaged, what sort of impairment is this similar to?
mesial temporal lobe damage
where does the primary somatosensory cortex sit on the brain?
the most anterior part of the parietal lobe
the prefrontal cortex is responsible for what sort of processes?
cog. control processes eg problem solving, planning, monitoring and self correction
where does the prefrontal cortex sit on the brain?
anterior in the frontal lobes
what role do the frontal lobes play in memory formation?
they play a large role in the organisational aspect of it (the executive side of it)
now how the memories are made, but where they are laid down and how easily you can access them
how can damage to the frontal lobes affect memory?
it can damage the mem ories regarding the context in which they are made `
what is confabulation? what does it result in?
damage to the prefrontal cortex, which results in the individual making statements of facts involving bizarre distortions of memory
what does DLPF stand for? what does it refer to?
dorsal, lateral, pre frontal
the area in which damage is most likely to result in impairment to chronological orders of memories
what it the Diencephalon? where is it found in the brain? what does it comprise of?
it is the “interbrain”
found right in the middle of the brain
comprises of thalamus and hypothalamus
the dorsal medial parts of the thalamus primarily are related to what part of the brain?
prefrontal cortex
damage to the thalamus often results in…?
damage to the corresponding part of the brain
why does damage to the thalamus sometimes lead to memory impairment?
because parts of the thalamus directly correspond to areas of the brain that are involved in memory function
which are more likely to cause memory deficits?
damage to the anterior medial parts of the thalamus or damage to the posterior lateral sections of the thalamus?
anterior medial parts
if you damage the mammillo-thlamic tract or the anterior thalamus, which type of memory deficit are you more likely to experience?
mesial temporal type
if you damage the medio dorsal nucleus and/or the internal medullary lamina, you are more likely to suffer from what type of memory impairment? which leads to issues of what?
more frontal type impairment.
difficulties in encoding memories in an organised way or the retrieval of the memories
what are Schwann cells? where is it found? what do they offer
myelin sheath, it is found around the axon and it encourages conduction of the electrical charge
what is an action potential?
a electrical process that propogates a neural message
what is the resting membrane potential of a cell body?
negative 70 mV
this is the electrical charge that the cell sits at
at what voltage does an action potential occur?
negative 55 mV
what does the successful firing of a cell result in?
allows for NT’s to be released across the synaptic clef
does one particular axon contain the one type of neurotransmitter?
yes
how are NT’s released into the synaptic clef?
a certain electrical charge voltage opens the gated Ca2+ channel (calcium) which releases NT’s
NT’s crossing the synaptic clef attach to what?
receptors in the dendrite
an inhibitory post synaptic potential does what?
reduces the voltage in the post synaptic cell
what is long term potentiation?
changes to the biochemistry of synapses the alter the effect on post synaptic neuron
what does long term potentiation involve?
a long term increase in the excitability of cell due to input from cell a
who described LTP? when?
Hebb, 1949
what is the result of LTP?
cell b undergoes some change where it responds more strongly to cell A
at a synaptic level, what 3 things are happening during LTP ?
- new receptors are inserted in the post synaptic membrane
- the receptors are more sensitive
- Cell a (pre synaptic membrane) releases more NTs
where does LTP most commonly take place?
parts of the brain most associated with memory eg hippocampus, Entorhinal cortex, thalamus, amygdala, and the visual, prefrontal and motor cortices
what is Long term depression in regards to synapses
decrease of synaptic strength due to low frequency stimulation at synapse
what is habituation in regards to synapses?
repeated stimulus reduces strength of synaptic response due to reduced NT release
what is sensitisation in regards to synapses?
single noxious stimulus causes exaggerated synaptic response to repeat presentation of noxious stimulus
Matlin’s definition of memory?
maintaining information overtime
Ashcroft’s definition of memory
mental processes of acquiring and retaining info for later retrieval
what is the main difference between terminology of implicit/explicit vs procedural/declarative?
procedural/declarative stemmed from trying to understand amnesia’s and place more emphasis on cog theories.