Broadbent, this explained the mechanism by which people can choose to attend to only one source of information at a time while excluding others. However, Broadbent's model failed to account for the observation that words of semantic importance, for example the individual's own name, can be instantly attended to despite having been in an unattended channel. Shortly after Broadbent's experiments, Oxford undergraduates Gray and Wedderburn repeated his dichotic listening tasks, altered with monosyllabic words that could form meaningful phrases, except that the words were divided across ears. For example, the words, "Dear, one, Jane," were sometimes presented in sequence to the right ear, while the words, "three, Aunt, six," were presented in a simultaneous, competing sequence to the left ear. Participants were more likely to remember, "Dear Aunt Jane," than to remember the numbers; they were also more likely to remember the words in the phrase order than to remember the numbers in the order they were presented. This finding goes against Broadbent's theory of complete filtration because the filter mechanism would not have time to switch between channels. This suggests that meaning may be processed first. Treisman In a later addition to this existing theory of selective attention, Anne Treisman developed the attenuation model. In this model, information, when processed through a filter mechanism, is not completely blocked out as Broadbent might suggest. Instead, the information is weakened (attenuated), allowing it to pass through all stages of processing at an unconscious level. Treisman also suggested a threshold mechanism whereby some words, on the basis of semantic importance, may grab one's attention from the unattended stream. One's own name, according to Treisman, has a low threshold value (i.e. it has a high level of meaning) and thus is recognized more easily. The same principle applies to words like fire, directing our attention to situations that may immediately require it. The only way this can happen, Treisman argued, is if information was being processed continuously in the unattended stream. Deutsch and Deutsch Diana Deutsch, best known for her work in music perception and auditory illusions, has also made important contributions to models of attention. In order to explain in more detail how words can be attended to on the basis of semantic importance, Deutsch & Deutsch and Norman proposed a model of attention which includes a second selection mechanism based on meaning. In what came to be known as the Deutsch-Norman