This notion of attention has two general meanings. Firstly, it refers to any situation in which one has to attend to more than one piece of information at the same time. Laboratory divided-attention tasks based on this definition include dual-task situations, multiple-target detection and visual search. Secondly, it only concerns situations in which one has to process multiple pieces of information, either looking or listening for certain special events referred to as targets, and then make one and only one response. The outcomes of divided-attention studies seem to differ depending on whether participants only have to make ‘Yes’ responses and do nothing when no targets appear, as in the ‘Go/no go task’, or to produce ‘Yes’ and ‘No’ responses depending on whether any targets are displayed. Thus, whether participants respond faster to two targets than just one seems to depend on whether the experimenter uses a ‘Go/no-Go’ or a ‘Yes/no’ task.
See Attention, Go/no go task