A Simon-like effect in Go/No-Go tasks performed in isolation.

The present study was conducted to decipher whether a spatial correspondence effect can emerge in Go/No-Go tasks (cSE, in reference to Donders' type c task) performed in isolation (participant alone in the cubicle). To this aim, a single participant was centrally positioned in front of a device and was required to respond by a hand key-press to the color of the stimulus. Half the participants were seated in front of a table equipped with only one response key and the other half in front of a table equipped with two response keys (one active and the other one useless). Using a substantial number of subjects (48) and trials (960), the present study revealed a numerically small but statistically reliable cSE. This result contrasts with referential coding predictions and suggests that the representation of a concurrently active response is not a prerequisite for the cSE to emerge. Moreover, the presence of a second response button in the participant's peripersonal space exerted no measurable influence on the cSE. The lack of statistical power of numerous previous studies may explain why the cSE has often been considered to be nil.