Glossary
Unconditioned Stimulus
What is an unconditioned stimulus?
In classical conditioning, an unconditioned stimulus (UCS) elicits a response without requiring the conditioning being studied. In Pavlov's work, food eliciting salivation is the familiar example.
Unconditioned and conditioned stimuli
A conditioned stimulus acquires its role through the conditioning procedure. A signal paired with food can later elicit a conditioned response.
Why it matters
The distinction concerns the stimulus's role in learning. Food is the stimulus in the example; salivation is the response.