Test-retest reliability of the simon task: a short version proposal.

Background: The standard version of the Simon task (an instrument for assessing attentional demands, inhibitory control and the perception-action cycle) comprises a total of 168 trials. Different versions of this task are used in the literature, but it is not clear whether the Simon effect can be found using brief versions of the test. Purpose: This study aims to investigate the presence of the Simon effect and its test-retest reliability in a brief version of 28 trials of the Simon task. Material and Methods: Ninety-two (92) subjects between the ages of 18-30 participated in this study. Participants performed two sessions (test and retest) in which the brief battery of the Simon task was used. Latency (reaction time - RT) and the accuracy (number of errors) were measured for the two typical conditions of the test (corresponding and non-corresponding). Results: A significant interaction (two-way ANOVA) between condition and moment (test vs. retest) was found for RT. Main effects were observed for both conditions (corresponding vs. non- corresponding) and moment (test vs. retest). A good measurement of reliability (alpha Cronbach = 0.883) was also observed. Conclusions: The 28-trial battery of the Simon Task seems to be efficient for eliciting the Simon Effect and it can therefore be considered reliable.