>>Synaptic strength is definitely a
measure of the strength of a temporal association between a condition
and an effect.<<
I am curious what work you would cite to support this. On the cellular
side of things, postsynaptic activity definitely matters at some, but not
all synapses. There is no single rule that applies to all forms of
plasticity - long-term changes need not follow a Hebbian rule (review the
hippocampus data - compare CA1 w/ CA3 - this is where much of the seminal
work on these phenomena have been done). Besides this, I am unclear what
you are referring to as a "condition" and an "effect". Can you provide a
simple example?