Neural Basis of Memory + models to explain learning Flashcards
neural plasticity
- ability of brain’s neural structure and/or function to be changed by experience throughout our life span
- plasticity indicates malleable or flexible- allows for learning and memory
- neural connections can be formed, removed or remade continually
- children’s brain more plastic than adult brains, and certain areas are more plastic than others
- more complex experience, the more distinctive structural change
synaptic plasticity
ability of the synapse to change over time
as we learn, brain rewires itself by changing structure and function
-existing connections can reorganise, new pathways form and strengthen during learning
Hebb’s rule
neurons that fire together, wire together
LTP and LTD
enduring long-lasting changes in synaptic strength brought about by specific activity patterns at synapses
LTP
long-lasting strengthening of synaptic connections, resulting in enhanced/more effective synaptic transmission
-improves ability of two neurons to communicate with one another at synapse
-postsynaptic neurons become more easily activated and more responsive to presynaptic neuron- through repeated stimulation by neurotransmitters
-more connection is activated, the more connection is strengthened.
-more strengthened connection, the more relevant neural pathway is strengthened, increasing efficiency of transferring info along pathway and decreasing forgetting of information
synapse formation, sprouting, rerouting and filigree appendages assist LTP
sprouting- dendritic branching
rerouting- undamaged neuron has lost connection with another neuron, seeks new active neuron to connect with
filigree appendages- new sprouts from axon terminals of presynaptic neuron towards the dendrites of postsynaptic neurons
associated with glutamate
LTD
long-lasting decrease in the strength of synaptic transmission
- results from lack of coactivation/prolonged low-level stimulation between pre and postsynaptic neurons
- synaptic pruning- weakening/elimination of unused/unwanted synapses
- follows rule use it or lose it
role of neurotransmitters/neurohormones
-generally, all enable communication of the information being learned and initiate or contribute to important structural changes at the synapse that ensure memory is durable and long-lasting when formed
similarities between neurohormones and neurotransmitters
similarities
chemical messengers
manufactured by neurons and released from axon terminal
differences
neurotransmitters- released into synaptic gap, travels more rapidly, remain in body for shorter
neurohormones- released into capillaries/bloodstreams, travel more slowly, take longer to exert their effect but remain in the body for longer.
role of glutamate in synaptic plasticity
- main excitatory neurotransmitter throughout the brain and enhances information transmission-makes postsynaptic neurons more likely to fire
- promotes growth and strengthening of synaptic connections
Consolidation
biological process of making a newly formed memory stable and enduring after learning
-time is required after learning to enable info to consolidate into LTM
-new info is temporarily stored in STM before transfer to LTM
-if interrupted, info won’t consolidate
-takes around 30 minutes following learning
-evidence comes from concussion, ECT
hippocampus plays crucial role in consolidation
-due to time dependency of consolidation, process is exposed to various factors- influence strength/durability of memory being formed- e.g stress hormones such as adrenaline
role of adrenaline in consolidation
adrenaline can enhance consolidation of LTM of emotionally arousing experiences- more likely to be well remembered
leaves lasting, highly vivid and detailed memories from personal perspective
-when released during emotional arousal, adrenaline induces noradrenaline release in the amygdala
-presence of noradrenaline during consolidation may activate amygdala to signal nearby hippocampus that details of relevant experience are important and LTM storage should be strengthened
more emotionally significant memories, the longer-lasting the memory is and has more detailed recall
has adaptive value, influencing future behaviour from past memories of danger
what is learning
relatively permanent change in behaviour that occurs as a result of experience
features of learning
-can be intentional/unintentional
-ongoing process
-can occur actively/passively
can be immediate/delayed
learning is relatively permanent
what is conditioning
process of learning associations between a stimulus and a behavioural response
Classical conditioning
form of learning that occurs through repeated association of two (or more) different stimuli
-previously NS elicits reflexive response by repeated association with UCS that automatically eleicits reflexive response
stimulus
event/object that elicits a response from an organsim
response- reaction made by an organism to a stimulus
