Selective attention is a cognitive process in which a person attends to one or a few sensory inputs while ignoring the other ones. Selective attention can be likened to the manner by which a bottleneck restricts the flow rate of a fluid. The bottleneck doesn’t allow the fluid to enter into the body of the bottle all at once; rather, it lets the fluid to enter in certain amounts depending on the flow rate, until all of it has entered the bottle’s body. Selective attention is necessary for us to attend consciously to sensory stimuli in such a way that we will not experience sensory overload.
There are three models that are associated to selective attention. These are the models of attention by Broadbent, Treisman, and Deutsch and Deutsch. They are also referred to as bottleneck models of attention because they explain how we cannot attend to all sensory input at one time in the conscious level.