In Donders' subractive method experiment, what did the participants have to do to avoid a shock?

In Donders' subtractive method experiment, participants were tasked with pressing a button when they felt a shock. This process was essential for assessing the reaction times associated with different cognitive processes involved in decision-making and motor responses. By recording the time taken for the participants to identify the shock and respond, researchers could estimate the duration of mental processes involved in perception and response execution. The experiment aimed to isolate specific mental operations by manipulating the conditions under which the stimulus was presented.

The ability to discern when a shock was presented and respond accordingly illustrates the cognitive processing that Donders was interested in measuring, which is why this specific action was integral to the experiment's aims. Thus, this choice aligns perfectly with the experimental design set out by Donders in his investigation of reaction times and the mental processes that contribute to them.