Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Acronyms, Wikipedia.
Related to stimulus: unconditioned stimulus, stimuli


1. any drug, agent, electrical impulse, or other factor able to cause a response in an organism
2. an object or event that is apprehended by the senses
3. Med a former name for stimulant



something that excites to action and motivates behavior. The concept of stimulus is characteristic primarily of those trends in psychology that base behavior analysis on the stimulus-response correlation (classical psychophysics and especially behaviorism, as well as neobehaviorism). The term “stimulus” is also retained in some psychological concepts that in essence supersede the stimulus-response correlation. Thus, for example, in the Würzburg school, a task or an awareness of a goal is considered to be a stimulus. In this case, the term “stimulus” is almost metaphorical. Even further from the term’s original meaning is the treatment it receives in the cultural and historical conceptions of L. S. Vygotskii, who established a functional difference between stimulus objects, at which action is directed, and stimulus means, by which action is accomplished. According to Vygotskii, signs serve as stimulus means.

In sociopsychological studies a distinction is sometimes made between motives as internal excitations and stimuli as external excitations to action (see Chelovek i ego rabota [collection], 1967, pp. 38–39).



(control systems)
A signal that affects the controlled variable in a control system.
An agent that produces a temporary change in physiological activity in an organism or in any of its parts.
References in periodicals archive ?
When a child's behavior is under stimulus control of a single feature that is identical to both stimuli, the percentage of correct responses rate would mimic chance levels.
In other cases, participants use the same name for all objects in the class as when saying "up" for all comparisons (Bn, Cn) reinforced in the presence of a nodal sample stimulus (An) resembling the shape of an arrow pointing upwards.
The fEMG data were integrated in 50 ms intervals during the first 1000 ms after stimulus onset.
The participants were informed about stimulus equivalence and the purpose of the experiment as they exited the experimental setting.
a You can do that by decreasing distance to X minus Y; by increasing movement of the stimulus at distance X (a child walking, skipping, or swinging her arms); by increasing number of stimuli (two or three children, instead of one); increasing the visual "threat" (a tall man instead of a short one, or a man with a beard instead of a clean-shaven one); or by increasing volume (if it's a stimulus that makes noise, such as a vacuum cleaner).
residential settings, schools), the PS procedures appear to be less time-consuming and more highly predictive than assessment procedures that involve presentation of each stimulus in isolation (i.
Valerie Ramey, an economist at the University of California at San Diego who has estimated multipliers, says that differences among studies often reflect their assumptions of how fast the economy would have grown without stimulus -- but, as she adds, we don't know that.
It's silly to compare owning shares of eBay or other publicly traded stocks with Senator Paxton's role as an influential owner in a private business profiting directly from the Obama stimulus package," Marquez said.
Most of the human studies addressing this issue have involved visual stimuli, and have produced data that seem to confirm the beneficial effect of stimulus comparison in generating the perceptual learning effect.
1964) showed that visual evoked potential (VEP) peak latency varies with stimulus luminance and higher luminance yields faster latency.