Both early and late selection refer to when in the perception process a stimulus is chosen to be processed, analyzed, and consequently understood. These selection models both follow a process of registering the information, perceptually analyzing it, semantically analyzing and encoding the information, then producing a response such as making a decision, remembering information, performing a task, etc. According to Gazzaniga et al. (2019), the early selection model of attention postulates that stimuli are selected for processing or disregarded before the perceptual analysis is done. This means the entire perceptual analysis does not need to be complete before selection or rejection of attention takes place. Whereas the late selection theorizes that all stimuli go through the same perceptual analyzing process and selection of stimuli that will produce one of the responses discussed above happens later in the perceptual process. This means that all stimuli are processed the same until they reach the semantic analysis/encoding stage.
There are several differences and characteristics that lead to early or late selection. For example, tasks that have aspects requiring great focus on a specific aspect of the job will require early selection and more focus where less demanding tasks are fine being functions with divided attention and late selection (Serences & Kastner, 2014). Knowing that, an example of early selection of attention would be sitting in a restaurant lobby and listening only for your name to be called while filtering out the other names or having a conversation in a crowded room and listening only to the person you are talking directly to. Examples of the late selection model include weighing all the choices in order to make a decision, sublimination perception, and understanding or remembering information that was not consciously attended to.