unconditioned stimulus


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stimulus

 [stim´u-lus] (L.)
any agent, act, or influence that produces functional or trophic reaction in a receptor or an irritable tissue.
conditioned stimulus a stimulus that acquires the ability to evoke a given response by repeatedly being linked with another stimulus that naturally evokes that response; see also conditioning.
depolarizing stimulus a stimulus that lowers the resting potential, making the inside of a fiber less negative. In cardiac fibers this means bringing the resting potential from −90 mV to −70 mV.
discriminative stimulus a stimulus associated with reinforcement, which exerts control over a given type of behavior; the subject must discriminate between closely related stimuli and respond positively only with this particular stimulus.
eliciting stimulus any stimulus, conditioned or unconditioned, that elicits a response.
threshold stimulus a stimulus that is just strong enough to elicit a response.
unconditioned stimulus any stimulus that naturally evokes a specific response; see also conditioning.

un·con·di·tion·ed stim·u·lus

a stimulus that elicits an unconditioned response; for example, food is an unconditioned stimulus for salivation, which in turn is an unconditioned response in a hungry animal. See: classical conditioning.

unconditioned stimulus

n. Psychology
A stimulus that evokes an unconditioned response.

un·con·di·tioned stim·u·lus

(ŭn'kŏn-dish'ŭnd stim'yū-lŭs)
That which elicits an unconditioned response; e.g., food is an unconditioned stimulus for salivation, which in turn is an unconditioned response in a hungry animal.

unconditioned stimulus

The stimulus that evokes an UNCONDITIONED RESPONSE.

stimulus

pl. stimuli [L.] any agent, act, or influence that produces functional or trophic reaction in a receptor or an irritable tissue.

conditioned stimulus
a neutral object or event that is psychologically related to a naturally stimulating object or event and which causes a conditioned response. See also conditioning.
discriminative stimulus
a stimulus associated with reinforcement, which exerts control over a particular form of behavior; the subject discriminates between closely related stimuli and responds positively only in the presence of that stimulus.
eliciting stimulus
any stimulus, conditioned or unconditioned, which elicits a response.
stimulus generalization
in learning by animals stimuli tend to be grouped together, the reactions lacking the discrimination of the higher mammals.
stimulus response coupling
coupling of the neural or endocrine stimulus to the cellular response.
structured stimulus
a well-organized and unambiguous stimulus, the perception of which is influenced to a greater extent by the characteristics of the stimulus than by those of the perceiver.
threshold stimulus
a stimulus that is just strong enough to elicit a response.
unconditioned stimulus
any stimulus that is capable of eliciting an unconditioned response. See also conditioning.
unstructured stimulus
an unclear or ambiguous stimulus, the perception of which is influenced to a greater extent by the characteristics of the perceiver than by those of the stimulus.
References in periodicals archive ?
Once the respondent relation is established, repeated occurrences of the conditioned stimulus without the unconditioned stimulus weaken the S-R relation until the conditioned stimulus elicits no response.
Learning for Mowrer was on the stimulus side in the association of the conditioned stimulus with the unconditioned stimulus, but what was changed (learned) were the emotions of hope and fear.
With respect to alcohol craving, a drop in blood alcohol levels would be considered the unconditioned stimulus that activates the unconditioned response (i.
Moreover, this occurred despite having balanced the physical form of the aversive and neutral prime, which would allow showing the prime's aversiveness net effect, regardless of whether its physical nature is identical or not to the unconditioned stimulus from the pre-conditioning phase.
While expectancy learning involves the activation of an expectation of a real ocurrence of the unconditioned stimulus (US), referential learning is thought to change the valence of the conditioned stimulus (CS) without generating an expectancy of the inminent occurrence of the US.
Training consists of exposing the animals to a bright white light (650-700 lux) for 6 s (the conditioned stimulus, CS), paired, after a 2-s delay, with a 4-s vigorous orbital shaking of the tray containing the animals (the unconditioned stimulus, US).
The conditioning paradigm used a noxious odor as the unconditioned stimulus because nausea is incompatible with sexual arousal (Maletzky, 1993).
The second assumption of the unified principle of reinforcement consists of three necessary conditions for the selection of behavioral relations: (a) the temporal relation between neutral stimuli and unconditioned stimuli (US); (b) the temporal relation between responses (R) and US; and (c) the evocation, by the unconditioned stimulus, of responses that would not have occurred in the absence of the US.
When it comes to testing BX after conditioning with AX, for subjects that have received blocked preexposure, responding will be partly determined by the ability of X to contact a representation of the unconditioned stimulus (US) by way of the associative chain X-A-US.
An experiment is reported in which the effect of unconditioned stimulus (US) intensity on latent inhibition (LI) was examined, using a two-stage conditioned emotional response (CER) procedure in rats.
In paired training, animals were exposed to a bright, white light (650-700 lux) for 6 s (the conditioned stimulus, CS) coincident with, after a 2-s delay, 4 s of vigorous agitation (the unconditioned stimulus, US).
In Pavlovian conditioning, temporal contiguity may be altered by increasing the time between the onset of the conditioned stimulus (CS) and the onset of the unconditioned stimulus (US), the CS-US interval.