Calibration of the unconditioned salivation reflex is achieved by measuring the number of saliva drops per amount of food eaten before any conditioned reflex is established.
A conditioned reflex is established by first presenting an event (the ringing of a bell, the starting of a metronome etc) and after a certain time (30 seconds) offering food. A typical experimental sequence will then show the building up of a conditioned reflex as the production of saliva before the food is offered. As the conditioned reflex is established the number of saliva drops increases with every repeat of the experiment and the time before salivation starts (the latency period) decreases:
| time of experiment | number of drops | latency period |
| 3.20 pm | 0 | --- |
| 3.28 pm | 0 | --- |
| 3.35 pm | 1 | 20 s |
| 3.39 pm | 3 | 10 s |
An inhibited response is produced by associating the offer of food with a negative experience (acid is offered instead of food). This leads to the suppression of salivation and refusal to eat when food is offered. The process can be quantified in the same way as described for conditioned reflexes.
Frolov, Y. P. (1937) Pavlov and his School; The Theory of Conditioned Reflexes. Kegan Paul, Trench, Trubner & Co. Ltd. Carter Lane E.C.