| Sumario: | 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 (<italic>μ</italic>, <italic>σ</italic>, and <italic>τ</italic>) 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 <italic>μ</italic> but not on <italic>τ</italic>, and a reverse Simon effect occurred on <italic>σ</italic>. In contrast, a positive word-based Simon effect was obtained on all these measures (including <italic>σ</italic>), and a positive arrow-based Simon effect was evident on mean RT, <italic>σ</italic>, and <italic>τ</italic> but not <italic>μ</italic>. The arrow-based Simon effect was not different from the word-based Simon effect on <italic>τ</italic> or <italic>σ</italic> but was on <italic>μ</italic> 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.
|
|---|