Effects of Perceptual Load on a Simon Task

Event Center BC

Perceptual load (PL) hypothesis claims that PL determines attentional selection. We questioned whether the PL effect can be generalized to other interference tasks, such as a Simon task. Participants performed a discrimination task with three levels of PL (No PL, Low PL, and High PL). There were four stimuli arranged in a horizontal fashion, and a target appeared at a near or far location from the fixation. In our previous study with a letter discrimination task, there were Simon effects for the No PL and Low PL, but not for High PL conditions. In the present study, we used a color discrimination task, and basically replicated our previous results, that there were Simon effects for No and low PL regardless of stimulus distance from the fixation. However, there was a Simon effect for high PL for far condition. The results suggest that stimulus discriminability affects the magnitude of the Simon effect.