memory

Question 1

define learning

Answer 1

acquisition of information

Question 2

define memory

Answer 2

storage of learned information

Question 3

define recall

Answer 3

reacquisition of stored info

Question 4

define engram

Answer 4

physical embodiment of memory

Question 5

independent memory systems

Answer 5

procedural = actions, skills - implicit - unavailable for conscious mind
declarative = knowledge, in words - explicit - available to conscious mind

explicit = consciously recalled
implicit = not consciously recalled (e.g. procedural, classical conditioning, priming)

Question 6

duration of memory

Answer 6

immediate = few seconds
STM = seconds - minutes (working memory)
LTM = infinite

Question 7

role of temporal lobe in memory

Answer 7

electrical stimulation of temporal lobe = hallucinations and recollection of past experiences
epileptic seizures = complex sensations and memories
patient HM = removal of part of temporal lobe due to epilepsy - maintained personality and intelligence, had extreme anterograde amnesia – no new memories - good working memories but couldn’t form new LTM

Question 8

brain structures and memory: PFC

Answer 8

involved in working memory

Question 9

brain structures and memory: hippocampus

Answer 9

converts STM to LTM - declarative memory
lesions here cause memory loss (HM)
structure = 3 layers of cortex
input from entorhinal cortex and beyond
outputs to many regions
enlarged in people who require good spatial memory - London taxi drivers

Question 10

brain structures and memory: amygdala

Answer 10

processed sensory inputs (e.g. smell), implicit emotions and learnt fear

Question 11

brain structures and memory: cerebellum

Answer 11

procedural memory, sensorimotor processing occurs here too

Question 12

mechanisms of memory - reverberating circuits

Answer 12

reverberating circuits = nerve impulses that were initially activated in response to stimuli are reactivated to recall information
memorising = dedicating neurons to this
active = remembering
inactive = not remembering

Question 13

Hebbian synapse concept

Answer 13

2 neurons active at same time = connection become stronger between them - leads to memory
2 neurons active at different times = connection between them weakens
activity is modifiable - plastic synapse

Question 14

synaptic plasticity

Answer 14

synaptic strength changes
facilitation or depression (strengthen or weaken)

short term (mins/hours):
Ca2+ availability / vesicle depletion -> not enough vesicles at presynaptic site = weakening of connection and depression

long term facilitation/depression:
sustained over days/weeks
mostly involves post-synaptic changes

Question 15

long term potentiation

Answer 15

persistent strengthening of synapses - increase in EPSP amplitudes

Question 16

tetanic long term potentiation

Answer 16

stimulating presynaptic neuron in high frequency bursts - leads to increased EPSP

Question 17

paired long term potentiation

Answer 17

stimulate pre and post synaptic at same time - coincident stimulus and depolarisation –> increased EPSP
explains classical conditioning - association of one stimulus with another, occur at same time, strengthens synapse between

Question 18

long term depression

Answer 18

LTD in hippocampus, decrease in amplitude of EPSP, weakening of synapse

Question 19

short-term habituation and sensitisation

Answer 19

habituation = decrease in response to same stimulus - get used to it
sensitisation = increase in response to same stimulus

Question 20

short term habituation and sensitisation animal studies

Answer 20

sea slugs
modify behaviours with gill withdrawal reflex
shocking tail = gill withdraws
touching after shock = quicker withdrawal = sensitisation

repeated gentle stimuli to tail = reduced gill withdrawal = habituation

Question 21

LTP with sea slugs

Answer 21

require receptor activation (glutamate, serotonin) - altered synaptic responsivity
mediated by secondary messengers (Ca2+ and cAMP)
— critical role of Ca2+ as a secondary messenger - activates protein kinases which phosphorylate proteins and increase AMPA receptors activity
trafficking of AMPA receptors to postsynaptic membrane
early stages require protein phosphorylation changes, late stages require protein synthesis
biochemical and structural pre and post synaptic changes