Stimulus (plural: stimuli) may refer to:

• Stimulus (physiology), in physiology, is something external that elicits or influences a physiological or psychological activity or response
• In psychology, anything effectively impinging upon any of the sensory apparatuses of a living organism, including physical phenomena both internal and external to the body.
• Stimulation, the action of various agents (stimuli) on muscles, nerves, or a sensory end organ
• In other fields, a stimulus is anything that may have an impact on a system; an input to the system. (E.g., an economic stimulus.)

Although related, the word's meaning is distinct from that of "stimulant."

See also

• Response
• Stimulus-response model

Perception

Reiz | Stiimul | Stimulus | Estímulo | Стимул | Stimulus | 刺激