a stimulus that elicits a response--known as an unconditioned response --that does not need to be learned by the animal
A stimulus that normally triggers a particular response. 815
In classical conditioning, the stimulus that produces what is initially the unconditioned response.
In Classical Conditioning, any stimulus that can elicit reactions from a subject with out prior conditioning.
Respondent behavior that is unlearned; a response is naturally emitted after exposure to a stimulus
Stimulus that, without prior training, elicits a reflexlike response (unconditioned response).
In classical conditioning, a stimulus that automatically elicits a response, typically via a reflex, without prior conditioning. See also conditioned response, conditioned stimulus, unconditioned response.