Behav. Res. Thu. Vol. 31, No. 6, pp. 617420, 1993 000%7967/93 $6.00 + 0.00 Printed in Great Britain. All rights reserved Copyright 0 1993 Pergamon Press Ltd zyxwvutsrqponm The utilisation of working memory by worry RONALD M. RAPEE Department of Psychology and Anxiety Disorders Clinic, University of Queensland, Brisbane, Australia, QLD 4072 (Received 20 August 1992) Summary-Sixty-eight undergraduate students were randomly allocated to one of four task conditions and required to worry about a topic of importance to them while simultaneously performing the task to which they had been allocated. The tasks differed in their ability to interfere with worrying. Generation of random letters was the only task to interfere significantly with the ability to worry. There was a nonsignificant tendency for articulatory suppression to produce some interference with worrying while visuo-spatial tasks did not affect the ability to worry. There was no difference in results between self-reported worriers and non-worriers. The results seem to indicate that worry primarily utilises the phonological aspect of the central executive of working memory. INTRODUCFION Research into the nature and understanding of worry as a specific component of emotional disorders has gathered pace in recent years. The suggestion that worry is an important aspect of emotional disorders and worthy of independent study has been primarily pursued by Borkovec (e.g. Borkovec, 1985; Borkovec & Inz, 1990; Borkovec, Robinson, Pruzinsky & DePree, 1983). This suggestion has received support from the area of test anxiety where factor analytic studies have indicated an independent cognitive component labelled ‘worry’ (Morris, Davis & Hutchings, 1981). In addition, in recent years the importance of worry has received added emphasis by changes to the diagnosis of generalized anxiety disorder (GAD) in the Diagnostic and Statistical Manual of Mental Disorders (3rd edn, Revised) (DSM-III-R, American Psychiatric Association, 1987). Based on these changes, worry is now considered to be the central feature of individuals with GAD (Rapee, 1991; Barlow, 1988). Understanding of anxiety and the anxiety disorders has been advanced in recent years by the application of information processing models to this emotion. However, while a number of features of the anxiety disorders have been clearly explained using such models, there have been few attempts to apply such explanations specifically to the concept of worry. However, these few attempts have fairly consistently suggested that worrying may primarily utilise working memory (Eysenck, 1979; Rapee, 1991). Working memory was originally proposed by Baddeley and Hitch (1974) as an extension of the concept of short-term memory. It is suggested that working memory acts as a temporary storage and manipulation center for information in order to help perform a number of cognitive tasks (Baddeley, 1990). Working memory is theoretically composed, at least partly, of three sub-systems: the phonological loop, the visuo-spatial sketchpad and the central executive. The phonological loop is responsible for the brief storage and manipulation of purely verbal information while the visuo-spatial sketchpad is an equivalent sub-system concerned with visual and spatial information (Baddeley, 1990). ‘Overseeing’ these two sub-systems is the central executive, essentially a type of attentional system which functions to control the two other systems. Application of these theoretical constructs to the phenomenon of worry, it has typically been suggested that worry would utilise primarily the central executive and possibly the phonological loop components of working memory (Eysenck, 1979; Rapee, 1991). These suggestions have been based either on evidence from the anxiety and performance literature (Eysenck. 1979) or on subjective descriptions of the verbal nature of worry (Borkovec & Inz, 1990). While there is little direct evidence to date on the utilisation of working memory by worry, two studies provide some support for this suggestion. Eysenck (1985) compared high- and low-trait anxious Ss on a letter transformation task. Subjects were instructed to mentally transpose letters according to a specified pattern in either the presence or absence of a monetary incentive for superior performance. Based on the pattern of results obtained, Eysenck concluded that anxiety affects primarily the central executive component of working memory with some possible inlluence also on the phonological loop. Given the importance of worry in the effects of anxiety on performance (Morris et al., 1981), it is possible that these results are primarily due to the worry component of anxiety. In a recent theoretical paper, Levey, Aldaz, Watts and Coyle (1991) suggested that articulatory suppression (a technique which primarily utilises the phonological loop) is likely to be a powerful technique for the treatment of insomnia (which is presumably largely maintained by worry). The authors reported support for this suggestion in a series of unsystematic cases. However, a systematic case study provided mixed results. The aim of the present study was to examine which, if any, sub-components of working memory were utilised by the process of worrying. This was done by having Ss simultaneously worry and attempt to perform tasks which utilised resources in different aspects of working memory. Subjects METHOD Subjects were volunteers from the first year psychology subject pool. Subjects were asked to volunteer in different recruitment drives if they considered themselves to be either ‘worriers’ or ‘non-worriers’. A total of 50 worriers (40 female, *Present address: School of Behavioural Sciences, Macquarie University, Sydney, NSW 2109, Australia. 617