In an experiment studying classical conditioning, a tone sounds and 0.5 seconds later a puff of air is delivered to a participant's eye. The participant blinks. This process is repeated once per minute. After a number of trials, the participant blinks as soon as the tone sounds and before the puff of air is actually delivered. Within the context of this example, what is the Conditioned Stimulus (CS)

The Tone

Explanation:

Conditioned Stimulus is a psychological term that describes the once neutral stimulus, in which certain individual or organism later learned, to make a response after becoming associated with the unconditioned stimuls

Hence, given the example in the question above, which is considered as classical conditioning, the puff of air is UNCONDITIONED STIMULUS, the blinking of an eye in response to the puff of air is an UNCONDITIONED RESPONSE, and the tone sound when a puff of air is perceived is the CONDITIONED STIMULUS. Therefore, at this stage, the response is considered as the Conditioned Response.