unconditioned stimulus


Also found in: Thesaurus, Medical, Legal, Acronyms, Encyclopedia, Wikipedia.
Related to unconditioned stimulus: classical conditioning, operant conditioning, unconditioned response, stimulus generalization

unconditioned stimulus

n. Psychology
A stimulus that evokes an unconditioned response.

unconditioned stimulus

n
(Psychology) psychol any stimulus evoking an unlearnt response, esp in the context of classical conditioning, in which the conditioned stimulus is followed by the unconditioned one
References in periodicals archive ?
A basic assumption in the Tombaugh and Tombaugh (1971) study was that a late signal (a signal occurring at the end of the reinforcement cycle) should enhance responding in a chained schedule because the temporal separation between the signal and food delivery should enhance the Pavlovian association between the signal and the unconditioned stimulus.
Hotsenpiller and Williams (1997) did a conditioning study using TMT as a potential conditioned stimulus by pairing it with an injection of a anxiogenic drug as an unconditioned stimulus.
In their most rudimentary form, Pavlovian conditioning accounts maintain that fear is a conditioned emotional response (CER) to a stimulus or event that is acquired via correlated pairings with an aversive or traumatic unconditioned stimulus (UCS) (Rescorla, 1988; Wolpe & Rachman, 1960).
The phenomenon was discovered in a conditioned suppression paradigm, in which it was shown that a stimulus failed to suppress responding when it appeared in a compound with an established conditioned suppressor, despite the contiguous relation between the stimulus compound and an unconditioned stimulus (Kamin, 1968, 1969).
This transfer of response from an unconditioned stimulus to a conditioned stimulus involved generalization from a sexually explicit stimulus to a nonsexually explicit stimulus.
In this way, the behavior displayed by each participant may have been respondent, as opposed to operant, and the preferred stimulus may have functioned as an unconditioned stimulus (US).
After the association is established, the conditioned stimulus can lead to emergence of response in the absence of the unconditioned stimulus.
It involves, on one hand, a stimulus and its triggered response (the unconditioned stimulus (US, food) and the unconditioned response (UR, salivation)), and, on the other hand, a conditioned stimulus (CS, bell's ring).
Typically, an unconditioned response or reflex that is elicited by an unconditioned stimulus will show habituation if the stimulus is repeated (Gluck et al.