by Saul McLeod published 2011

Divided attention concerns the ability to perform two tasks simultaneously.

Eysenck and Keane (1995) identify three factors which affect the performance of dual tasks (DT).

1. Task Difficulty (the more difficult the less successful the DT performance)

2. Task Practice (improve DT performance)

3. Task Similarity (non-similar tasks are easier, perhaps use different resources)

Experimental Studies

Studies of divided attention typically use the ‘dual task experiment’.

–  Get people to perform multiple tasks, in order to compare performance with single-task conditions.

–  Often find that performance suffers.

The interpretation of dual-task experiments follow the view that human information processing resources are limited and shareable and that they can be subdivided into several classes.

Allport et al (1972) found that skilled pianists were able to sight read music and shadow speech at the same time.

Practice may have an effect:

a) Using attentional resources more economically.

b) Developing new strategies to minimize the interference between tasks.

Shaffer (1975) reported the case of an expert typist who could type from sight whilst shadowing speech.

Task Similarity Research

Several studies have found that task similarity is an important factor determining our ability to perform two tasks at the same time.  Researchers such as McLeod (1977) and Treisman and Davies (1973) have found that dual-task performance is greatly improved when the two tasks are dissimilar (e.g., in different sensory modalities).

However, while task similarity is relatively easy to measure and manipulate in a laboratory environment, it is much harder to measure the similarity of more everyday tasks, such as driving or playing the piano, for example.

Practice Research

Practice is another factor determining dual-task performance. Researchers such as Spelke et al. (1976) have found that, with practice, participants can greatly improve their dual-task performance (e.g., dictation and reading for comprehension).

They even go so far as to suggest that with practice, we can perform two tasks together equally well. However, this claim has been challenged and further studies have shown that although practice can increase dual-task performance, performance is not as good as when each task is performed alone.

Task difficulty Research

The third main factor determining dual-task performance is task difficulty. Researchers such as Duncan (1979) have found that increasing the difficulty of the tasks reduces performance and vice versa.

However, as with task similarity, it is very difficult to define task difficulty, particularly with everyday tasks.

In summary, research suggests that two dissimilar, highly practiced and simple tasks can be performed well together, whereas two similar, novel and complex tasks cannot.

References

Allport, D. A., Antonis, B., & Reynolds, P. (1972). On the division of attention: A disproof of the single-channel hypothesis. Quarterly Journal of Experimental Psychology, 24, 225–235.

Duncan, J. (1979). Divided attention: The whole is more than the sum of its parts. Dual-task interference as an indicator of on-line programming in simple movement sequences. Journal of Experimental Psychology: Human Perception and Performance, 5(2), 216–228.

Eysenck, M. W., & Keane, M. T. (1990). Cognitive psychology: A student's handbook. Hove: Lawrence Erlbaum Associates Ltd.

McLeod, P. (1977). A dual task response modality effect: Support for multiprocessor models of attention. Quarterly Journal of Experi-mental Psychology, 29, 651-667.

Shaffer, L. H. I (I975). Control processes in typing. Quarterly Journal of Experimental Psychology, 27, 419-432.

Spelke, E. S., Hirst, W. C., & Neisser, U. (1976). Skills of divided attention. Cognition, 4, 215-230.

Treisman, A., & Davies, A. (1973). Dividing attention to ear and eye. In S. Kornblulm (Ed.), Attention and Performance IV (pp. 101-117). New York: Academic Press.

How to cite this article:

McLeod, S. A. (2011). . Retrieved from