Delay Conditioning?

• A. The conditioned stimulus is presented after the unconditioned stimulus ends.
• B. The conditioned stimulus is presented after a long delay with no overlap.
• C. The conditioned stimulus is presented only after the response occurs.
• D. The conditioned stimulus is presented and overlapped by the unconditioned stimulus.

Answer: (D)

Timing of the conditioned stimulus relative to the unconditioned stimulus defines how Pavlovian learning is formed. In delay conditioning, the CS begins before the US and continues as the US is presented, so the two stimuli overlap in time. This overlap creates a strong predictive link: the CS signals that the US is coming, so the organism learns to respond to the CS with a conditioned response.

If the CS were presented after the US ends, there would be no cue predicting the US in advance, so conditioning wouldn’t develop in the same way. If there’s a long gap with no overlap between CS and US, that’s trace conditioning, where learning is less robust because the temporal contiguity is reduced. If the CS appeared only after the response occurred, that wouldn’t establish the anticipatory cue characteristic of Pavlovian conditioning at all. And if the CS is presented and overlapped by the US, that exact timing—CS starting first and continuing into the US—characterizes delay conditioning.