A dominant theory in the anxiety-working memory literature is the Processing Efficiency Theory (Eysenck & Calvo, 1992). According to this theory, worry - the cognitive component of state anxiety - pre-empts capacity in the central executive and phonological loop components within Baddeley and Hitch's (1974) fixed-capacity working memory system. Central to the Processing Efficiency Theory is the distinction between performance effectiveness (i.e. quality of performance) and processing efficiency (i.e. performance effectiveness divided by effort), with anxiety proposed to impair efficiency to a greater extent than it does effectiveness. The existing literature has provided support for this theory, although there exist factors that complicate the findings, including the nature of the working memory tasks utilised, comorbid depression, and the distinction between trait and state anxiety. Clarification of the limiting factors in the anxiety-working memory literature was sought over a series of initial methodological studies. The first study was an initial step in addressing the issue of comorbid depression, identifying measures that maximised the distinction between anxiety and depression. The second study identified verbal and spatial span tasks suitable for examining the various working memory systems. The third study considered a possible role for somatic anxiety in the anxiety-working memory relationship, and additionally addressed the state/trait anxiety distinction. These three initial studies culminated in the fourth study which formally addressed the predictions of the Processing Efficiency Theory, and explored the cognitive/somatic anxiety distinction more fully. For the third and fourth studies, high and low trait anxious individuals underwent either cognitive (ego threat instruction) or somatic (anxious music) stress manipulations, and completed a series of span tasks assessing all components of the working memory system. Unexpectedly, the fourth study yielded a notable absence of robust effects in support of the Processing Efficiency Theory. A consideration of the research into the fractionation of central executive processes, together with an examination of tasks utilised in the existing literature, suggested that anxiety might not affect all central executive processes equally. Specifically, the tasks utilised in this programme of research predominantly invoke the process of updating, and it has recently been suggested that anxiety may not actually impair this process (Dutke & Stober, 2001). This queried whether the current conceptualisation of the central executive component as a unified working memory system within the PET was adequate or if greater specification of this component was necessary. One central executive process identified as possibly mediating the anxiety-working memory relationship is that of inhibition, and the focus of the fifth study thus shifted to clarifying this more complex relationship. In addition to one of the verbal span tasks utilised in the third and fourth studies, the reading span task (Daneman & Carpenter, 1980) and a grammatical reasoning task (MacLeod & Donnellan, 1993) were also included. Inhibitory processing was measured using the directed ignoring task (Hopko, Ashcraft, Gute, Ruggerio, & Lewis, 1998). This study established that inhibition was affected by a cognitive stress manipulation and inhibition also played a part in the anxiety-working memory link. However other central executive processes were also implicated, suggesting a need for greater specification of the central executive component of working memory within the PET. A finding that also emerged from this, and the third and fourth studies, was that situational stress, rather than trait or state anxiety, was predominantly responsible for impairments in working memory. Finally, a theoretical analysis placing the anxiety-working memory relationship within a wider context was pursued, specifically examining how the Processing Efficiency Theory is nested within other accounts examining the relationship between mood and working memory. In particular, similarities between the theoretical accounts of the relationships between anxiety and working memory, and depression and working memory, suggest the operation of similar mechanisms in the way each mood impacts on performance. Despite the similarities, potential distinctions between the impact each has on performance are identified, and recommendations for future research are made.
| Identifer | oai:union.ndltd.org:ADTP/221021 |
| Date | January 2003 |
| Creators | Chong, Joyce L.Y. |
| Publisher | University of Western Australia. School of Psychology |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright Joyce L.Y. Chong, http://www.itpo.uwa.edu.au/UWA-Computer-And-Software-Use-Regulations.html |
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