Models of attention within the human brain have been developed throughout history. A great deal of research was completed in the 1950s and 1960s to expand on attention of the human brain, which is the process of deciding on which information is important and which should be ignored or classed as less important. Theories are set forth in each of the different models of attention to explain how the human brain processes information and decides which should be processed. The three main models are known as the Broadbent model, the Treisman model, and the Deutsch and Deutsch model.
Donald Broadbent produced a model of attention known as the filter model in 1958, but now known as the Broadbent model. Studies were completed by Broadbent on military air traffic controllers receiving and sending large amounts of information at one time. Large amounts of information produced a bottleneck that is sorted through by the brain in a sensory filter that decides on the importance of each piece of information. Pieces of information that do not get processed, or are classed as not important, decay rapidly in the sensory filter. Broadbent's theory puts forward the case that information is sorted in the brain for relevance before it is processed in the conscious parts of the brain.
Treisman’s attenuation model was developed in 1960 as a different model of attention to the Broadbent model, with attenuation referring to the ability of the human brain to turn down the strength of the information passing to it when it is classed as unimportant or less important than other information. Attention is focused in this model on information deemed important by the individual, while information seen as not as important is processed less thoroughly by the human brain. During this attenuation model, the information is processed for physical characteristics and the recognition of words through a filter. Each piece of information is passed through a filter, similarly to the Broadbent model, to create a bottleneck that must be then filtered for importance. Completion of experiments to back up Treisman’s theory included the use of information passed through headphones in large quantities of overlapping information.
A third model of attention is known as the Deutsch and Deutsch model, which is similar to Treisman’s theory of attenuation. Deutsch and Deutsch puts forward the theory that all of the information passed to a human works through the complete set of mechanisms of the mind whether attention is focused on the information or not. Only information that is distinguished as meeting the highest level of importance at that specific time is pushed forward and focused upon. Treisman’s theory differs from Deutsch and Deutsch because, in Treisman, selection of important information is done at an early stage of information processing. Deutsch and Deutsch argues that information is sorted for importance at the end of the mechanisms for assigning importance within the brain.
Bottleneck models of attention provided the initial research into how attention is focused when the senses of a human are overloaded with information. Problems with bottleneck theories are based on the requirement for information to be overloaded on the person being tested, with test subjects not being faced with only a small number of information choices. Shifting attention between information is not allowed during these bottleneck models of attention.