Does task-set reconfiguration create cognitive slack?

Abstract
C. Oriet and P. Jolicoeur (2003) reported 2 experiments in which the perceptual contrast of stimuli was manipulated in a task-switching paradigm. They failed to observe an interaction in the reaction time data between task switching, perceptual contrast, and response-stimulus interval. Using the locus of slack logic, they concluded from these results that early perceptual processing of stimuli awaits the completion of a task-set reconfiguration stage, rather than proceeding in parallel with it. Here, an assumption necessary for this argument is questioned, and it is shown that an existing computational model of task switching, without successive stages for task-set reconfiguration and perceptual processing, produces a similar pattern of data. Thus, C. Oriet and P. Jolicoeur's data are compatible with models in which early perceptual processing and task-set reconfiguration take place in parallel.