New voices: the curious case of Sherlock Holmes and perceptual load

It is of the highest importance in the art of detection to be able to recognise, out of a number of facts, which are incidental and which are vital. Otherwise your energy and attention must be dissipated instead of being concentrated (Conan Doyle, 1894/2001, p.391.) The preceding quote is elegant enough to have been written by William James in The Principles of Psychology (1890) as an explanation of our essential cognitive ability to focus our attention on relevant goal-directed information, while ignoring irrelevant and potentially distracting noise. Yet it is actually a description of the deductive processes of that most extraordinary of consulting detectives, Mr Sherlock Holmes. For Holmes, the ability to select only those relevant clues that are required to solve a case, while ignoring irrelevant and extraneous information that could cloud his reasoning, is an indispensible element of his expertise. Psychological research has made great progress over the last 60 years in understanding the cognitive and perceptual mechanisms that govern this essential selective process.