Question

1. two groups of rats receive classical conditioning trials in which a tone and electric shock are presented. for group 1 the electric shock always follows the tone. for group 2 the tone and shock occur randomly. which of the following is likely to result? a) the tone will become a cs for group 1 but not for group 2. b) the tone will become a cs for group 2 but not for group 1. c) the tone will become a cs for both groups. d) the tone will not become a cs for either group. 12. for the most rapid conditioning, a cs should be presented: a) about 1 second after the us. b) about a half - second before the us. c) about 15 seconds before the us. d) at the same time as the us. 13. during extinction, the ____ is omitted; as a result, the __ seems to disappear. a) us; ur b) cs; cr c) us; cr d) cs; ur 14. in pavlov’s studies of classical conditioning of a dog’s salivary responses, spontaneous recovery occurred: a) during acquisition, when the cs was first paired with the us. b) during extinction, when the cs was first presented by itself. c) when the cs was reintroduced following extinction of the cr and a rest period. d) during discrimination training, when several conditioned stimuli were introduced. 15. when a conditioned stimulus is presented without an accompanying unconditioned stimulus, ____ will soon take place. a) generalization b) discrimination c) extinction d) aversion

Explanation:

1. Question 11: In classical - conditioning, for a neutral stimulus to become a conditioned stimulus (CS), there must be a reliable association between it and an unconditioned stimulus (US). In Group 1, the shock always follows the tone, creating a reliable association, so the tone can become a CS. In Group 2, the tone and shock occur randomly, so there is no reliable association for the tone to become a CS.
2. Question 12: For the most rapid conditioning, a CS should be presented about a half - second before the US. This timing allows the organism to anticipate the US.
3. Question 13: During extinction in classical conditioning, the US is omitted. As a result, the conditioned response (CR) seems to disappear.
4. Question 14: Spontaneous recovery in Pavlov's studies occurred when the CS was reintroduced following extinction of the CR and a rest period. After extinction, the CR fades, but after a break, presenting the CS again can cause the CR to reappear.
5. Question 15: When a conditioned stimulus is presented without an accompanying unconditioned stimulus, extinction will soon take place. The conditioned response weakens and eventually disappears.

Answer:

1. A. The tone will become a CS for Group 1 but not for Group 2.
2. B. about a half - second before the US.
3. C. US; CR
4. B. during extinction, when the CS was first presented by itself.
5. C. extinction