Task-irrelevant spatial information, conveyed by stimulus location, location word, or arrow direction, can influence the response to task-relevant attributes, generating the location-, word-, and arrow-based Simon effects. We examined whether different mechanisms are involved in the generation of these Simon effects by fitting a mathematical ex-Gaussian function to empirical response time (RT) distributions. Specifically, we tested whether which ex-Gaussian parameters (mu, sigma, and tau) show Simon effects and whether the location-, word, and arrow-based effects are on different parameters. Results show that the location-based Simon effect occurred on mean RT and mu but not on tau, and a reverse Simon effect occurred on sigma. In contrast, a positive word-based Simon effect was obtained on all these measures (including sigma), and a positive arrow-based Simon effect was evident on mean RT, sigma, and tau but not mu. The arrow-based Simon effect was not different from the word-based Simon effect on tau or sigma but was on mu and mean RT. These distinct results on mean RT and ex-Gaussian parameters provide evidence that spatial information conveyed by the various location modes are different in the time-course of activation.