LTP in input A is an instance of Hebbian (associative) plasticity because the response of pathway A to the test stimulus was modified not by its training stimulus (LFS of A does not induce LTP, as shown in top left), but because it was active at the same time that another input to the cell (input B) received a plasticity-inducing HFS. This is the associative property of LTP. Synapse specificity and associativity are two properties that any model of associative memory should possess.
