What is the difference between late and early selection models?

What is the difference between late and early selection models?

Many of the early selection models involve the idea of a "filter" that acts on incoming information. It allows only the attended message to pass and to be processed, other information is kept out.
Late selection models on the other hand propose that almost all of the information available is processed to the level of meaning before selection takes place. An example in line with late selection models was conducted by McKay. Participants were presented the sentence "They were throwing stones at the bank" to the attended ear, and biasing words, such as "river or "money" to the other. What McKay found was that the biasing words influenced the participant's interpretation of the original sentence. (They were throwing stones at the river bank vs. the loan and savings association.) This provides evidence that the biasing words, presented to the unattended ear, were processed to the level of meaning. A process that the early selection models rule out.

The early and late selection models refer to how attention is controlled. The early selection model proposed by Broadbent states that information is passed through 4 stages. After it's perceived it's stored very briefly in the 1)sensory memory. Then it moves onto the 2) filter which filters out the relevant information based on physical characteristics (when talking with Kasia in a crowded room I filter out her voice from all the different voices based on the way I know her voice sounds). Information that passes through the filter gets to the 3) detector which processes everything it's presented with to determine its meaning. Finally the information reaches 4)short-term memory.
The early selection model proposed by Treisman replaces the filter with an attenuator which analyzes the incoming information from the perspective of its physical characteristics, language formation and meaning.
The difference between the late and early selection model is the stage at which the meaning of the information is assessed. In the late model it happens at the third stage (the detector), after the information supposedly had been filtered based on its physical characteristics. In the early selection model the assessment of meaning happens at the second stage, right after the information has come from sensory memory. In the early selection model no information is lost due to filtering before meaning assessment.

In early selection, the unattended message does not processed for meaning while in the late selection, the unattended message does processed for meaning