In 1963, Deutsch & Deutsch proposed a late selection model of how selective attention operates. They proposed all stimuli get processed in full, with the crucial difference being a filter placed later in the information processing routine, just before the entrance into working memory. The late selection process supposedly operated on the semantic characteristics of a message, barring inputs from memory and subsequent awareness if they did not possess desired content. According to this model, the depreciated awareness of unattended stimuli came from denial into working memory and the controlled generation of responses to it. The Deutsch & Deutsch model was later revised by Norman in 1968, who added that the strength of an input was also an important factor for its selection.

The Deutsch & Deutsch (1963) model is called a late selection model because they claim that all information (attended and unattended) is analysed for meaning in order to select an input for full awareness. Whether or not information is selected is dependent on how relevant it is at the time.

Focused Attention

The same evidence supporting Treisman's model supports this theory. However, the Deutsch & Deutsch model explains the process of focused attention more simply. More support comes from Moray (1969), who paired electric shocks with a word to condition a galvanic skin response (GSR) when the word was spoken. A GSR was produced even when the word was presented to the unattended ear and the participants were unaware of it.

Further evidence for the late selection model is that unattended messages can influence participant's understanding of the meaning of ambiguous sentences (MacKay, 1973):

Focused Attention

It seems unlikely that all information should be processed semantically before we are made aware of it. This suggestion is backed up by evidence that we are better at spotting key words in attended messages than unattended messages - according to Deutsch & Deutsch we should be equally as good at each.

Information from all channels is perceptually processed –

·      Selection occurs late, after perceptual processing has interpreted the stimulus

·      Processing bottleneck occurs when items have to be placed in short-term memory

A criticism of both the original Deutsch & Deutsch model, as well as the revised Deutsch–Norman selection model is that all stimuli, including those deemed irrelevant, are processed fully. When contrast against Treisman's attenuation model, the late selection approach appears wasteful with its thorough processing of all information before selection of admittance into working memory.