THEORIES OF SELECTIVE ATTENTION
Kahneman and Treisman (1984, p.55) have succinctly described the main disagreement between early selection and late selection theories of attention: 'The classic question of attention theory has always been whether attention controls the build-up of perceptual information, or merely selects among the responses associated with currently active percepts.' Early selection theories hold that attention serves to select which one of a number of stimuli will be further semantically processed and stored in long term memory. On the other hand, more recent late selection theories maintain that selective attention operates after all stimuli are semantically processed. This essay briefly examines and discusses the main findings and criticisms that have caused the transition from early selection models to late selection models of attention. Apart from these two extreme positions, theories that combine aspects of both theories are also discussed.The essential question which, if answered, would provide evidence on whether stimuli are semantically processed before or after selection is what people know about the unattended information. If the subject does not know the meaning of unattended information, this would mean that it has been discard
These two previous experiments had numerous weaknesses. In Cherry's experiment subjects were asked about information in non-shadowed messages after they had completed the shadowing phase. This information may have been perceived and processed, but forgotten later. In Broadbent's experiment there was no particular meaning to be extracted from the pairs of digits presented, so there was no sufficient evidence to draw conclusions about semantic processing. Moreover, it was later made clear that it is possible to easily switch attention from one ear to another, when the meaning of the unattended message was relevant to the shadowed message. Ellis, H.C. & Hunt, R.R. (1993). Fundamentals of cognitive psychology (5th ed). Brown & Benchmark. Madison Parkin, A.J.(1999).Essential Cognitive Psychology. Draft 23-3-99. University of Sussex. The evidence and theories mentioned in this essay lead to the conclusion that humans can detect meaning in unattended stimuli. There is no evidence, however, that this semantic processing is as complete as the processing of attended stimuli. Nevertheless, it could also be said that this conclusion is a rough generalisation, as there is no clear indication that there is a unique attentional mechanism responsible for attending all kinds of stimuli. Visual attention, for example may be controlled by different mechanisms than auditory attention. There is still no theory that provides a clear and testable explanation for all the known evidence and localises attentional selection. The main reason for this difficulty is that it is almost impossible to devise an experiment that will localise selection without interfering with the subjects' natural functioning.
Some common words found in the essay are:
Eysenck Keane, Kahneman Treisman, According Broadbent, Deutsch Deutsch, Grey Wedderburn, Caslett Suffran, parkin 1999, Hunt RR, MT1995 Cognitive, Johnston Heinz, eysenck keane 1995, semantically processed, eysenck keane, late selection, keane 1995, Gray Wedderburn, meaning unattended, visual attention, stimuli semantically, semantic processing, stimuli semantically processed, unattended stimuli, late selection theories, 1960 parkin 1999, meaning unattended stimuli,
Approximate Word count = 1386
Approximate Pages = 6 (250 words per page double spaced)
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