PSYCH U3 AOS2 - LEARNING Flashcards
what is neural plasticity?
the ability of the brain’s neural structure or function to be changed by experiences. Occurs during embryonic development through to old age. Triggered by learning experiences, maturation, to compensate for, and overcome brain damage.
This may involve a single neuron, a pair of neighbouring neurons or entire networks of neurons.
what is synaptic plasticity?
ability of the synapse to change. Change may occur through growth or formation of new synaptic connections that strengthen the synapse or change may occur through disuse of synaptic connections that weaken or eliminate the synapse. The structure of the brain is remodelled by experience.
what is long term potentiation?
Refers to the long lasting strengthening of synaptic connections due to repeated activation of the same neural pathways.
Repeated stimulation of neural pathways strengthens the likelihood of the neurons in this pathway firing again, subsequently enhancing the ability of pre and post synaptic neurons in the neural pathway to communicate.
This causes permanent functional and structural changes that lead to a long term memory being stored.
what does long term potentiation result in?
results in postsynaptic neurons being more easily activated and more responsive to the presynaptic neurons as a consequence of repeated stimulation by neurotransmitters. The more the connection is activated - the more it is strengthened - increasing the efficiency in transferring info along that pathway. Constant activation of these pathways creates memories.
what are functional changes in enural plasticity?
increase in the amount of neurotransmitter produced and released by the presynaptic neuron to cause an effect in the postsynaptic neuron. Increased sensitivity of receptor sites on the postsynaptic neuron - firing more readily
what are structural changes in neural plasticity?
The amount of branching at the ends of dendrite at the synapse increases, resulting in more connections between presynaptic and postsynaptic neurons.
enlarged axon terminals
More AMPA and NMDA receptors
what is long term depression?
Long lasting decrease in the strength of synaptic transmission. Is a result of either a LACK of stimulation of pre and postsynaptic neuron, or a LOW LEVEL stimulation.
The postsynaptic neuron becomes less responsive to neurotransmitters released by the presynaptic connection and weakens synaptic connections.
This is important for learning and memory because the weakening of unused synapses through LTD can eliminate unwanted connections, leaving only the important connections that have been strengthened through repeated use by LTP.
what is the purpose of LTD?
Increases the likelihood of forgetting; Allows us to prune or eliminate useless/unwanted memories, and block or eliminate inappropriate/unwanted feelings or behaviours: allows us to edit or adjust thinking when performing a skill or problem solving eg. forgetting incorrect spelling of a word.
similarities between LTD and LTP?
both are activity dependent i.e. more or less activity
both involve glutamate
both occur at glutamate synapses
both involve changes in excitability
both are long-lasting effects
Both are forms of long lasting neural plasticity.
Both ensure an efficient neural
system.
Both involved in memory and learning
differeces between LTP and LTD?
Strengthening vs weakening of synaptic connections
Increase vs decrease in number of dendrites etc.
Enhanced more efficient synaptic transmission in LTP, but less efficient synaptic transmission in LTD.
LTP allows us to strengthen important/ wanted/ useful memories whereas LTD means that old, previously learned information or skills can be cleared out, allowing us to adjust, edit or correct our thinking if problem solving or our movements if performing a skill.
what are neurotransmitters?
chemical messengers that are manufactured (made) by neurons and released from axon terminals.
They are released locally at a synapse and exert their exhibatory or inhibitory effects on adjacent postsynaptic neurons. They enable communication of information being learned and leads to functional and structural changes at the synapse to ensure that a memory is long lasting.
what are neourhormones
A chemical messenger manufactured by a neuron and released from axon terminals that is released into the bloodstream and carried to target neurons or cells.
They are released into capillaries where they are absorbed into the bloodstream and carried to cells.
The effects of neurohormones can be on distant cells or organs some time after their secretion (long-lasting effects). Some neurotransmitters can also occur as neurohormones (adrenalin and noradrenalin are examples of these).
what is the role of glutamate?
In learning and memory, glutamate plays crucial roles in the synaptic changes that occur - promotes the growth & strengthening of synaptic connections between neurons within a pathway (that represents the memory of what has been learned)
Glutamate is vital in the role of LTP & LTD - the more often that glutamate can excite an adjacent neuron, the more it contributes to LTP (and vice versa for LTD).
what is the role of adrenaline in the concolisation of memories?
Adrenaline can enhance the consolidation of long term memories of emotionally arousing experiences (pleasant or unpleasant) so they’re more likely to be remembered . Significant stress-inducing events (often unpleasant) typically leave memories that are lasting, vivid & highly detailed
Adrenaline induces the release of noradrenaline in the amygdala (which has a crucial role in processing emotions).
This presence of noradrenaline in consolidation may activate the amygdala to signal the nearby hippocampus - telling the hippocampus that the memory is of significance & it should be strengthened and consolidated.
when is adrenaline adaptive or non-adaptive?
This is an adaptive response because it is important to remember potential dangers/threats to increase chances of survival in our environment so we remember what not to do next time.
However, it can be maladaptive: Phobias - every time the event resurfaces, adrenaline may be released, thereby maintaining the strength of the memory each time it is reconsolidated.
what is the neutral stimulus in CC?
A stimulus that does not naturally elicit any specific response (becomes the Conditioned Stimulus) BUT after repeated pairings with the UCS it becomes the CS.
Pavlov’s Experiment = Bell
what is the unconditioned stimulus in CC?
Any stimulus that consistently produces a particular, naturally occurring, automatic, involuntary response.
Requires no learning to produce the response which is automatic/reflex response
Pavlov’s Experiment = Meat Powder (food)
what is the unconditioned response in CC?
The response that occurs automatically when the UCS is presented. Reflexive, involuntary response brought on by the UCS
Pavlov’s experiment = Salivation to the presence of food (UCS)
what is the conditioned stimulus in CC?
stimulus that is neutral at the start of the conditioning process, and does NOT normally produce the UCR
But, through repeated pairings (associations) with the UCS, the CS triggers a similar response to that of UCS. It becomes the CS when alone (without the USC) it elicits the conditioned response.
Pavlov’s Experiment = Bell
what is the conditioned response in CC?
The learned response that is produced by the CS (alone). The CR occurs after the NS has been associated with the UCS and has become a CS. Occurs after the pairings of the CS with the UCS. Need to say what it is in response to - in response to the CS. CR is very similar to that of the UCR but is triggered by the CS alone.
Pavlov’s Experiment= Salivation to CS
