Simon Effect - Original Experiment

Original Experiment

In Simon's original study, two lights (the stimulus) were placed on a rotating circular panel. This device would be rotated at varying degrees (away from the horizontal plane). Simon wished to see if an alteration of the spatial relationship, relative to the response keys, affected performance. Age was also a probable factor in reaction time. As predicted the reaction time of the groups increased based on the relative position of the light stimulus (age was not a factor). The reaction time increased by as much as 30%. (Simon & Wolf, 1963).

However, what is usually seen as the first genuine demonstration of the effect that became known as the Simon effect is by Simon & Rudell (1967). Here, they had participants respond to the words "left" and "right" that were randomly presented to the left or right ear. Although the auditory location was completely irrelevant to the task, participants showed marked increases in reaction latency if the location of the stimulus was not the same as the required response (if, for example, they were to react left to a word that was presented in the right ear).