Stimulus (psychology)

In psychology, a stimulus is any object or event that elicits a sensory or behavioral response in an organism.

[1] The study of the stimulus in psychology began with experiments in the 18th century.

This may have led James J. Gibson to conclude that "whatever could be controlled by an experimenter and applied to an observer could be thought of as a stimulus" in early psychological studies with humans, while around the same time, the term stimulus described anything eliciting a reflex in animal research.

Pavlov then trained the dog by ringing the bell every time before food.

Emotional stimuli were regarded as not eliciting a response; instead, they were thought to modify the strength or vigor with which a behavior is carried out.