Humans are better at responding to a stimulus when subjects know in advance which type of movement is expected. We are also better at detecting a visual object in a natural scene when we know in advance about its features, e.g. location, motion or colour.
These effects depend on our ability to represent advance information, in order to use it to process information quicker. In general, the representations that are involved in the selection of task-relevant stimuli and responses are called ‘attentional sets’. They are called ‘motor sets’, for motor actions, and ‘perceptual sets’ for object detection.
Source: Corbetta, M. and Shulman, G.L. (2002) ‘Control of goal-directed and stimulus-driven attention in the brain’, Nature Reviews. Neuroscience, 3(3), pp. 201–215. Available at: https://doi.org/10.1038/nrn755.