The location-, word-, and arrow-based Simon effects: An ex-Gaussian analysis

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Factors

Background:

• The Simon effect demonstrates how task-irrelevant spatial information influences response selection.
• Previous research has identified location-, word-, and arrow-based Simon effects, but the underlying mechanisms remain unclear.

Purpose of the Study:

• To investigate whether different mechanisms generate the location-, word-, and arrow-based Simon effects.
• To determine which parameters of response time distributions are affected by each type of Simon effect.

Main Methods:

• Fitting an ex-Gaussian function to empirical response time (RT) distributions.
• Analyzing the effects of location, word, and arrow cues on RT distribution parameters (mean RT, μ, σ, τ).

Main Results:

• Location-based Simon effect influenced mean RT and μ, with a reverse effect on σ.
• Word-based Simon effect positively affected mean RT, μ, σ, and τ.
• Arrow-based Simon effect affected mean RT, σ, and τ, but not μ.

Conclusions:

• Distinct mechanisms underlie the generation of location-, word-, and arrow-based Simon effects.
• The temporal activation patterns of spatial information differ across stimulus modalities (location, word, arrow).
• Ex-Gaussian parameter analysis provides nuanced insights into Simon effect generation beyond mean RT.