Figure 4.3 | Stimulus Generalization and Discrimination | These are idealized stimulus generalization and discrimination results following classical conditioning of the salivary response (CR) in dogs to a tone of 1,000 Hz (CS). The strength of the CR to generalization test stimuli (all tones except the 1,000 Hz tone) decreases as the similarity of the test stimulus to the original CS decreases. These generalization responses, however, can be extinguished through discrimination training in which the UCS (food) only follows the 1,000 Hz tone. The CR to each of the other tones will be extinguished except for the tones so similar to the 1,000 Hz tone (975 Hz and 1,025 Hz) that the dog does not perceive them as different.