You Are Right!: Spatial Instructions Increase Social Simon Effects
In the social Simon task, two participants perform a spatial compatibility task together, each of them responding to only one stimulus (e.g., one participant reacts to red, the other to green stimuli). Participants show joint spatial compatibility effects (SCEs), that is, they respond faster when their go-stimulus appears on their half of the screen. Effects are absent when the same go/no-go task is performed without a coactor. Joint SCEs were originally explained in terms of shared task representations, but recent research suggests that effects result from spatial response coding: in joint go/no-go tasks, participants perceive themselves as the right/left participant operating a right/left response key. While previous research showed that the spatial alignment of keys and seats influences the effect, the present research demonstrates that merely instructing participants to be the right/left participant operating a right/left response key instead of labeling participants and keys with arbitrary numbers substantially increases joint SCEs.