Answer:
US: The US stands for the unconditioned stimulus. In this scenario, the puff of air to the eye is the unconditioned stimulus because it naturally and automatically causes the eye to blink without any prior learning or conditioning.
UR: The UR stands for the unconditioned response. In this case, the unconditioned response is the eye blink that occurs in response to the puff of air to the eye. The eye blink is an automatic and reflexive response that happens naturally without any prior conditioning.
CS: The CS stands for the conditioned stimulus. It is a previously neutral stimulus that, through repeated pairing with the unconditioned stimulus, comes to elicit a response. In this case, the tap on the shoulder becomes the conditioned stimulus because it is repeatedly paired with the puff of air to the eye.
CR: The CR stands for the conditioned response. It is the learned response that is elicited by the conditioned stimulus. In this scenario, the conditioned response is the eye blink that occurs in response to the tap on the shoulder alone, after it has been repeatedly paired with the puff of air to the eye.
NS: The NS stands for the neutral stimulus. It is a stimulus that does not elicit a response before any conditioning occurs. In this case, the tap on the shoulder is initially a neutral stimulus because it does not cause the eye to blink before it is paired with the puff of air to the eye. However, after repeated pairings, it becomes the conditioned stimulus and elicits the conditioned response of an eye blink.