Donald Eric Broadbent (Birmingham, May 6, 1926-April 10, 1993) was an influential English experimental psychologist^[1]. His career and his research work bridged the gap between the pre-Second World War approach of Sir Frederick Bartlett and its wartime development into applied psychology, and what from the late 1960s became known as cognitive psychology.

Educated at the University of Cambridge, in 1958 he became director of the Applied Psychology Research Unit which had been set up there by the UK Medical Research Council on Bartlett's persuasion in 1944. Although much of the work of the APRU was directed at practical issues of military or industrial significance, Broadbent rapidly became well known for his theoretical work. His theories of selective attention and short-term memory were developed as digital computers were beginning to become available to the academic community, and were among the first to use computer analogies to make a serious contribution to the analysis of human cognition. They were combined to form what became known as the "single channel hypothesis". His Filter Model proposed that the physical characteristics (e.g., pitch, loudness) of an auditorily presented message were used to focus attention to only a single message. Broadbent's Filter model is referred to as an early selection model because irrelevant messages are filtered out before the stimulus information is processed for meaning. These and other theories were brought together in his 1958 book "Perception and Communication" which remains one of the classic texts of cognitive psychology^[2]. In 1974 Broadbent became a fellow of Wolfson College, Oxford and returned to applied problems, developing new ideas about implicit learning from consideration of human performance in complex industrial processes along with his colleague Dianne Berry.

[edit] Broadbent's Filter Model

Accounts for a theoretical filter device, which is located in between the incoming sensory register, and the short-term memory storage. His theory is based upon the multi-storage paradigm of William James (1890) and later the Atkinson & Shiffrin's 'multi-store' memory model (1968). This filter functions together with a buffer, and enables the subject to handle two kinds of stimuli, presented at the same time. One of the inputs is allowed through the filter, while the other is waiting in in the buffer for later processing. The filter prevents overloading of the limited capacity mechanism beyond the filter, which is the short-term memory^[2]. Broadbent comes up with the theory based on data from an experiment where three pairs of different digits are presented simultaneously, three digits in one ear and three in the other. Most participants recalled the digits ear by ear, rather than pair by pair. Thus, if 496 were presented to one ear and 852 to the other, the recall would be 496852 rather than 489562.

The theory has difficulties explaining the famous cocktail party effect of the British scientist Colin Cherry, who is trying to explain how we are able to focus our attention towards the stimuli which we find most interesting.^[3]

A lecture in Broadbent's honour is given at the annual conference of the British Psychological Society.

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