unconditioned stimulus


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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 ?
Concentrated lemon juice was used as unconditioned stimulus (US), which has been used in previous studies to produce a salivary response (see Pangborn, 1968).
Control pups learned to avoid the unconditioned stimulus by running into the other compartment during the unconditioned stimulus on almost all experimental days and recorded a high success rate of avoidance response (Fig.
Four research assistants were involved, one of whom had volunteered to be videotaped and exposed to an eliciting stimulus; we initially needed to determine an effective unconditioned stimulus (US) with which to elicit the startle reflex, with the designated volunteer out of the room.
1999) Renewal to the signal value of an unconditioned stimulus.
Previous studies have implicated a brain structure called the amygdala in the acquisition and expression of conditioned fear, this occurring when a stimulus (the conditioned stimulus, CS) becomes associated with an aversive object or event (the unconditioned stimulus, UCS).
However, reflex relations may be temporarily weakened by repeated presentation of the unconditioned stimulus.
2002)in which a neutral conditioned stimulus is paired with a fear-inducing unconditioned stimulus, so that animals come to exhibit a conditioned fear response to the conditioned stimulus.
consolidated memory; CR, conditioned response; CS, conditioned stimulus; LLD, long-lasting depolarization; LTM, long-term memory; NSW, natural seawater; PKC, protein kinase C; Ro-32, Ro-32-0432, or bisindolylmaleimide-XI; RTE, random training event; STM, short-term memory; TE, training event; UCR, unconditioned response; US, unconditioned stimulus.
In classical experiments, one must remove an unconditioned stimulus from time to time in order to recognize the conditioned response.
For each trial, a 5-sec conditioned stimulus (CS), consisting of a buzzer and light, was followed by a 5-sec unconditioned stimulus (UCS), which included a scrambled shock of 0.
An unconditioned stimulus elicits an unlearned response, while a conditioned stimulus paired with the unconditioned