Figure 1. Sequence for presentation of a dual task (signal and/or arithmetical task). The signal is presented at the time t = 0 and lasts 1.5 s; the arithmetical tasks can appear on the screen at 8 points in time in relation to the beginning of the signal (time differential DTAS = -1.4 s to 3.5 s) and remains there for 2 / 4 s (test I/II). The possibility of responding to a signal exists for 2.5 s and of solving the arithmetical task (test I/II) for 4 / 7.5 s. Up to the next dual task there is a break of 10 to 16 s randomly selected. An example is given for DTAS = 0.7 s for the single arithmetical task.