6 How to Store a Memory Flashcards
3 main stages in Atkinson and Shiffrin’s (1971) multi-store model of memory
-> Sensory memory -> short-term memory -> long-term memory
Who was an important theorist who helped shape biopsychology in the 20th century? And what did he do?
Donald Hebb (1904-1985), each psychological significant event, sensation, percept. expectation, memory or thought is a result of a particular pattern of activity in a group of interconnected neurons (cell assembly).
what did Donald Hebb theorise about the short and long term memory?
Short-term memory: ‘reverberating’ activity in networks of neurons
Long-term memory: stored by changing the strength of connections between neurons in a network.
Reactivation of a memory involves the reactivation of an assembly (network) of neurons.
Reactivation of a particular pattern occurs between the differential synaptic strength.
What is Hebbian Learning?
When the postsynaptic and the presynaptic cell fire together then the connection between them in strengthened. (cells that fire together stay together.
Evidence for Hebbian-type synapse-strenthening mechanism?
- Synapses can be strengthened by artificial stimulation: Long-Term Potentiation (LTP)
(Can cause neurons to fire by electrocuting certain neurons, this would make some stronger but it would only last a year)
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If there is a little bit of activity in pathway 2 it will strengthen the synaps. So you need A and B to strengthen synapses.
What is LTP?
Long-term potentiation (LTP) is a process involving persistent strengthening of synapses that leads to a long-lasting increase in signal transmission between neurons. It is an important process in the context of synaptic plasticity. LTP recording is widely recognized as a cellular model for the study of memory.
Long term potentiation (LTP) induction mechanism
Glutamate is involed in the rapid transformation of information?
Calium ions flowing into the cell and are what cause long term potential. This is important because you can find drugs that block these receptors.
How to test whether Long term potentiation LTP has anything to do with memory?
- Show that blocking LTP prevents memory formation
- Show that reversal of LTP produces forgetting
- Show that learning leads to LTP-like changes
- Show that producing LTP creates false memories or masks existing memories.
What is the Morris water maze?
Study where drug is given to rats during a training period. This blocks the creation of memories and stops the ability for animals to form memories.
What is the Morris water maze?
Study where drug is given to rats during a training period. This blocks the creation of memories and stops the ability for animals to form memories.
Why does LTP maintenance depend on PKM?
Is a substance required in the brain so that if this is blocked then you can’t maintain LTP
PKMz inhibitation with ZIP reverses the maintenance of late phase LTP in vivo.
Train animals to learn how this thing works and them uses shocks.
Test with control or not control (saline)
Turn shocks off
Groups with ZIPS just don’t seem to remember areas you get shocks in.
PKM inhibition abolosihes long-term retention of spatial information.
How to show that learning leads to LTP-like changes?
Motor learning promotes branch-specific spine formation.
Where, new spines occurred after learning in rats, some also dissapared. (big changes in connections over all).
This spine learning could be blocked by the NMDA antagonist.
What would happen if synapse kept on getting strengthened?
More activity in neurons would create a positive feedback loop.
Semantic scaling occurs so that the relative input into the cell stays the same. The net input of the cell stays the same. It is a form of homeostasis.
