Time-course analysis of temporal preparation on central processes

Participants usually respond faster to a response signal (RS) when this signal is preceded by a warning stimulus than when it is not. A question of theoretical importance is the locus of this facilitating effect within the information processing stream. Recently, Los and Schut (Cogn Psychol 57:20-55, 2008) suggested that temporal preparation acts on central processes while perception of the RS is under way. The present study provides a stochastic model (central preparation model, CPM) based on this hypothesis and presents three experiments testing this model. To track the complete time-course of temporal preparation, the warning signal could either precede or follow the RS. The data show some systematic deviation from the model's predictions, questioning CPM's assumption that temporal preparation acts only on central processes. An alternative mechanism of temporal preparation based on the parallel grains model [Miller and Ulrich (Cogn Psychol 46:101-151, 2003)] is discussed.