Memory Flashcards
Define learning
Acquisition of information
Define memory
Storage of learned information
Define recall
Reacquisition of stored information
Define the engram
Physical embodiment of a memory
What is procedural memory
Skills and associations
- Largely unavailable to conscious minds
- Changes in the brain when these skills are learned
What is declarative memory?
Facts or evens
- Available to conscious mind
- Can be taught
Encoded in symbols and language
What is explicit memory?
Memory can be consciously recalled
What is implicit memory?
Memory that cannot be consciously recalled
What are the different types of implicit memory?
Procedural memory
Classical conditioning
Priming (one stimulus influences the response to subsequent stimuli)
Duration of immediate memory
Few seconds
Duration of short term memory
Seconds or minutes
Duration of long term memory
Days, months or years
What is working memory?
Memories are immediately memorised in a loop but are not stored in long term
Describe patient HM
Temporal lobotomy of epileptic part of brain
- New memories weren’t able to be formed
(Anterograde amnesia)
What memory is processed in the frontal lobe?
The working memory
What memory is processed in the hippocampus?
Converting short to long term
- Declarative
- Spatial memory formation
What occurs in the amygdala?
Multiple, processed sensory inputs
Implicit, emotional and learnt fear
What memory is processed in the cerebellum?
Procedural
Sensorimotor
What do hippocampus lesions cause?
Formation of new memories is lost
Describe the structure of the hippocampus
Three layered cortex
Where are the hippocampus inputs?
Entorhinal cortex
How does a connection between 2 neurons become stronger?
They must be active (spiking) at the same time
What is the Hebbian synapse concept?
Activity is modifiable in neurons
Synapses are plastic
Define facilitation
An increase in synapse strength
Describe depression in a synapse
A weakened synapse with less postsynaptic effect
What is short term facilitation?
Vesicle depletion
- The synapse is weaker due to less vesicles to transport neurotransmitters
What is long term potentiation?
Persistent strengthening of synapses leading to long lasting increases in synaptic transmission between neurons
Where does LTP occur?
In the Hippocampus between CA3 neuron and CA1 neuron (pre and postsynaptic neurons)
How does LTP affect the EPSP?
Increases EPSP amplitude
How does LTD affect the EPSP?
Decreases EPSP amplitude
Define sensitisation
Increased response to the same stimulus leads to modification
What is habituation?
Memory formation due to repeated behaviours
What do changes in synaptic strength require?
Receptor activation of glutamate and serotonin
What are LTP, LTD and APLYSIA mediated by?
Second messenger (Ca2+ and cAMP)
How does LTP occur?
Pre synapse is filled with glutamate release neurotransmitter into cleft
-> Recognised by receptors
Action of AMPA receptor
Depolarises the membrane
Action of NDMA receptor
Release Ca2+ into post synaptic neuron, activates protein kinase
-> Phosphorylates proteins and increased the activity of AMPA
