mechanisms of learning Flashcards
what should we want to learn?2
contiguity and contingency
what are two computational approaches to learning?
hebbs rule and BCM rule, LTD
what is flexibility in associations that are made?
potential to unlearn and relearn associations (extinction and reconditioning)
what is 2nd order conditioning?
ability to build upon earlier learning experiences
when does conditioning occur for forward, simultanenious and backwards pairing of contiguity?
only for forward and simultaneously
where is long term potentiation present in brain?
visual cortex, audotroy cortex and hippocampal areas
what are the effects of activity levels on inputs of LTP?
low= no LTP. middle range = takes a lot of spikes/time and high - few/quick spikes
what is stage 1 of pre-synaptic LTP?
glutamate released from pre-synaptic cell, NMDA blocked by mg
what happens when weak excitation of pre-synaptci LTP?
na entry through AMPA channel, NMDA still blocked by mg
what happes when strong excitation of pre-synaptic LTP?
lots of na entry via AMPA channel, strong excitation means depolarised post-synaptic spine
what does a depolarised post-synaptic spine do?
pushes mg block away
what is hebbs rule?
that a synapse should be strengthened when both the input and target were active
what does the BCM rule and LTD suggest about a synapse? 4
increase when pre and post highly active, decrease(LTD) if only slightly active, stays same if some in between activity and no change value based on past activity
