When Pavlov rang a bell, the dogs salivated.

The presence of a tone increases the probability that the dog will salivate.

The salivary response would grow weaker, and eventually the dog would no longer salivate when the bell rang.

As for psychological testing leading to progress, pull the other one - it's got bells on that, when they ring, make my dog salivate.

Soon Pavlov could make his dog salivate just by sounding the bell, even without bringing its food (Figure 3.8).

When exposed to the bell ringing without wearing the harness, the dogs did not salivate.

The dogs only salivated upon hearing the bell while wearing the harness.

He'd heard of Pavlov's dog, of course; he could even recall what made the dog salivate and what the saliva meant.

After a time, the dog would salivate whenever it heard the bell, whether food was present or not.