Final answer:
During extinction training, the reappearance of conditioned responses after periods of rest is called spontaneous recovery.
Step-by-step explanation:
During extinction training, the reappearance of conditioned responses after periods of rest is called spontaneous recovery. This phenomenon occurs when a previously extinguished conditioned response returns following a rest period. For example, if a dog has been trained to salivate in response to a bell, but then the bell is repeatedly presented without being followed by food (extinction), the dog may show a weakened response. However, if the dog is given a break from the training and then the bell is presented again, the dog may start salivating again, indicating spontaneous recovery.