Simon effect: what is it and how is it studied in psychology?

The Simon effect is a psychological phenomenon related to interference processes.

Sometimes people have such automated responses in our brain that conflicts arise when solving certain tasks that "contradict" such automation. In this article we will learn about one of these interferences, the Simon effect.

The Simon effect was proposed by J.R. Simon at the end of the 1960s, and consists of responding faster and more accurately when the stimulus to be detected appears in the same relative space as the response to be emitted.

The Simon effect: what does it consist of?

In a study proper to basic psychologywhich consisted of an auditory task in which the subjects had to identify the frequency at which a certain sound was emitted by pressing the button located on the right for low frequencies and the left for high frequencies. The sounds were presented randomly in one ear or the other.

Although the initial hypothesis of the paradigm was that the source of the sound was irrelevant to the task, the results of the study contradicted this hypothesis, as subjects tended to respond stereotypically in the same direction as the source of the stimulus: this phenomenon, discovered by Simon and Berbaum (1990), is known as the Simon effect.

The Simon effect is considered an interference phenomenonIt is located at the stage of response selection by the subject (when the subject must respond). That is, this means that such an effect affects the response stage in information processing.

Thus, the Simon effect refers to the fact that the reaction times of a subject when responding are usually faster, and the reactions or responses more accurate (more precise), when the stimulus to be detected appears in the same relative location as the response (as we have seen above). (as we have seen above). This happens even if the location of the stimulus is irrelevant to the task to be performed.

The name of the effect is due to the fact that it was J.R. Simon who first published this phenomenon in the late 1960s. J.R. Simon's original explanation was that there is an "innate tendency to respond to the source of the stimulus", the source being understood as the place of origin of the stimulus.

In other words, the Simon effect effect appears in a given task when there is an interference with the stimulus.In this case, the position of the stimulus and the assigned response do not correspond. The effect would be the result of a conflict between the irrelevant information coming from its spatial position (e.g., it appears to the right) and the relevant information conveyed by the stimulus.

Models of information processing

Simple models of information processing establish three stages for information processing:

• Stimulus identification.
• Response selection.
• Response execution or motor stage.

In this sense, as we have already seen, it is thought that the simon effect would imply an interference in the second stage, the response selection stage.

J.R. Simon's explanation

J.R. Simon (1969) argues that the position of the stimulus (even if irrelevant to the task) directly influences response selection. This is because there is an automatic tendency to react towards the source of the stimulus, so that performance is worse if the stimulus that appears there demands an opposite response.

Explanations for understanding the Simon effect mostly allude to the aforementioned interference in the response selection stage when making a decision; neurologically, the anterior cingulate cortex is thought to be involved, neurologically, the anterior cingulate cortex is thought to be involved in such processing, and it is thought that it may be responsible for this.and it is thought that it could be responsible for originating the Simon effect.

Thus, it can be argued that the information of the position or source of the stimulus could not be ignored, and would significantly affect our decision or response, even if the responding subject knows that the information is irrelevant.

Other explanations

Another explanation for the Simon effect is that it is due to the automatic generation of conflicting spatial codes. Thus, the fact that the Simon effect is of greater magnitude when responses are emitted relatively quickly, suggests that it may be dependent on an automatically generated spatial codewhich remains active for a brief period.

On the other hand, and in turn, the inverse Simon effect shows that it is possible for the effect to appear with slower responses, demonstrating the possible involvement of intentional logical recoding processes under the subject's control.

The Stroop Effect

The Simon effect produces an interference similar to that occurring in the Stroop effect. The Stroop effect (or Jaensch effect) consists of a semantic interference produced as a consequence of our automaticity when we read; this occurs when the meaning of the word interferes with the task of naming, for example, the color with which it is written.

Thus, if for example we see the word "red" written in black, and we must say the color and not the word, we will take longer to respond and we will make a mistake more easily than if the word is "black", it is written in black, and we must also say the color (because it matches).

Bibliographical references:

• Alvarado, J.M. and Santisteban, C. (2004). Response compatibility and the Simon Jesús Mª Alvarado and Carmen Santisteban effect. Psicothema, 16,(2), 276-281.
• Simon, J. R. (1969). Reactions toward the stimulus source. Journal of experimental psychology, 81, 174-176.
• Simon, J. R., Acosta, E. Jr., Mewaldt, S. P., & Speidel, C. R. (1976). The effect of an irrelevant directional cue on choice reaction time: Duration of the phenomenon and its relation to stages of processing. Perception and Psychophysics, 19, 16-22.
• Simon, J.R. y Berbaum, K. (1990). Effect of conflicting cues on information processing: the «Stroop effect» vs. the «Simon effect». Acta Psychologica, 73, 159-170