memory & learning Flashcards
(19 cards)
Learning is defined as
Memory is defined as
acquisition of new info/knowledge needed for adaption
retention of the learned information to be retrieved and used later
declarative (explicit) memory is
available for conscious recollection - events /facts
easy to learn/ forget
non declarative memory Is
not available for collection
requires repetition over a long period of time- musical instruments
less likely to be forgotten
Long term
short term
(declarative)
recalled after long time period
lasts for short period of time - vulnerable to disruption
memory consolidation is via
info stored as short term first then as long term afterwards
info is stored as long term straight after a stimulus
Amnesia ( loss of memory)
dissociated - no other deficits in cognitive performance other than memory loss
retrograde - forget things previous to that event
anterograde- can’t learn new things after trauma
transient global - lose memory of everything, identity, not pernament
where is declarative memory stored
medial temporal lobe - hippocampus
cortical association areas
parahippocampal region
role of the Cortex
info from sensory modality stored in the cortical region that serves that modality
medial temporal lobe
consolidation of declarative memory
temp storage in MTL/ consolidation in cortex
hippocampus
spatial memory- place cells
working memory- on going behaviours
relational- times of memory change
Hebbs theory
strength of connection not controlled by genes
· When an axon of an cell A is near enough to excite cell B, or repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A’s efficiency, as one of the cells firing B, is increased.’
engram of an object -
assembly of cortical cells activated by stimuli, reciprocal connections - short term
long term consolidation
-fire/ wire together
-LTP/ LDP
-modification of existing synapses
-
how can synapses become stronger?
when strong activation of synapses leads to firing of PSN, leads to potentiation of the PSN response
- coincidence of pre/PSN firing
- LTP/ LTD
explain the process of LTP
- PSN release Glu
- binding to AMPA R on PSN
- triggers depol in Vm
- removal of Mg block on NMDA R (sufficient V)
- Glu binds to NMDA R
- Ca influx through NMDA channel
- activates Ca dependent kinases inside cell (CaMK2)
- AMPA R increased conductance to Na and increased insertion of preformed R into PSN membrane
- Ca influx amplifies ability to respond to Glu
LTP
LTD
for consistent/ strong coinciding firing
for occasionally coinciding firing
N that fire together have something in common- respond to same stimuli
Neurotrophins …
- activated by synaptic activity
- enhanced Post SN responsiveness
- enhanced pre SN release
- enhanced membrane excitability
- modification of transmission and connectivity
variation in synaptic plasticity
limbic - most plastic
association of cortical regions - less
PS/ motor areas - rigid
