Simon and his friends

Studies using the Simon task have consistently reported faster stimulus-response compatible trials referring to the compatibility in regard to the body midline of the responding agent (egocentric). We have recently developed a variant of the Simon task (Baess & Bermeitinger, submitted) simultaneously allowing the formation of multiple spatial reference frames. Using stick-figure manikins as stimuli, we found evidence for Simon effects based on the egocentric and allocentric (ball in the left or right hand of the manikin) reference frame, which were further modulated by a non-spatial reference frame (one manikin vs. nine manikins). Here, we present a new series of experiments using photos of human agents as stimuli. In line with those results from the stick-figure manikins, egocentric and allocentric Simon effects were obtained. However, the allocentric Simon effect was inverted providing evidence for taking the human agent’s perspective on the photo into account (e.g., my right hand equals his right hand). Implications will be drawn on basis of the findings from the stick-figure manikin and the human agent experiments.