Attenuation theory

Attenuation theory is a model of selective attention proposed by Anne Treisman, and can be seen as a revision of Donald Broadbent's filter model. Treisman proposed attenuation theory as a means to explain how unattended stimuli sometimes came to be processed in a more rigorous manner than what Broadbent's filter model could account for. As a result, attenuation theory added layers of sophistication to Broadbent's original idea of how selective attention might operate: claiming that instead of a filter which barred unattended inputs from ever entering awareness, it was a process of attenuation. Thus, the attenuation of unattended stimuli would make it difficult, but not impossible to extract meaningful content from irrelevant inputs, so long as stimuli still possessed sufficient "strength" after attenuation to make it through a hierarchical analysis process.

Selective attention theories are aimed at explaining why and how individuals tend to process only certain parts of the world surrounding them, while ignoring others. Given that sensory information is constantly besieging us from the five sensory modalities, it was of interest to not only pinpoint where selection of attention took place, but also explain how we prioritize and process sensory inputs. Early theories of attention such as those proposed by Broadbent and Treisman took a bottleneck perspective. That is, they inferred that it was impossible to attend to all the sensory information available at any one time due to limited processing capacity. As a result of this limited capacity to process sensory information, there was believed to be a filter that would prevent overload by reducing the amount of information passed on for processing.

Early research came from an era primarily focused upon audition and explaining phenomena such as the cocktail party effect. From this stemmed interest about how we can pick and choose to attend to certain sounds in our surroundings, and at a deeper level, how the processing of attended speech signals differ from those not attended to. Auditory attention is often described as the selection of a channel, message, ear, stimulus, or in the more general phrasing used by Treisman, the "selection between inputs". As audition became the preferred way of examining selective attention, so too did the testing procedures of dichotic listening and shadowing.

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