Cognitive-behavioral models of psychopathology often postulate roles for more than one cognitive bias in the maintenance of a given disorder. Furthermore, these models often imply bidirectional effects, where one bias or its results influences another bias or the effects of that second bias, and vice versa. It also seems likely that, given that a person may be processing information in more than one system at any one time, these processes and their results may combine to maintain a disorder. The alternative possibility, that cognitive biases always act in isolation, seems implausible, so that at least some combined effects seem correspondingly quite likely. Despite the fact that the cognitive-behavioral models of psychological disorders often postulate such combined processes, clinical psychological research has tended to examine cognitive processes in isolation. Even when different biases are assessed within the same study, they are often not examined with a view to how their combination might maintain disorders (although there are some notable exceptions, e.g., Watkins & Teasdale, 2004 and Wells & Papageorgiou, 1998). We propose that a number of biased cognitive processes often operate simultaneously and/or in succession and that these cognitive processes are likely to work together in various ways serving to maintain specific emotional disorders. In the present paper we focus on one specific disorder—social phobia—and consider how two types of biased cognitive process act in combination and may help to maintain the disorder.
Individuals with social phobia exhibit a number of cognitive biases related to threatening information, including biased attention, selective interpretation, negative self-imagery, and elevated subjective risk (see Hirsch & Clark, 2004, for review). Most research on cognitive processes in social phobia has examined processes in isolation (e.g., Roth, Anthony, & Swinson, 2001), which provides important information about the biases that exist but does not elucidate the role one bias has on another. Some researchers have investigated more than one bias within the same study (e.g., Brendle & Wenzel, 2004, Mansell & Clark, 1999 and Wenzel et al., 2005); although highly informative, these studies do not provide information about the causal role one bias has during the operation of another. In order to assess causality, it is necessary to manipulate one process and then assess its impact on another cognitive process (e.g., Hirsch et al., 2003 and Hirsch et al., 2003). The current paper focuses on negative biases of interpretation and self-imagery in the maintenance of social phobia. To anticipate, we argue that these processes combine to maintain social phobia, although we also argue that such combinations of cognitive biases are not confined to imagery and interpretation and probably apply equally to other cognitive biases and to other psychological problems.
The proposal that cognitive biases work together will be referred to as the combined cognitive biases hypothesis: that cognitive biases do not operate in isolation, but rather (a) can influence each another and/or (b) can interact so that the impact of each on another variable (e.g. social anxiety) is influenced by the other. Via both these mechanisms we argue that combinations of biases have a greater impact on disorders than if individual cognitive processes acted in isolation.
Imagery and Interpretation in Social Phobia
Mental imagery in psychological disorders
Reports of spontaneous mental images are common in the anxiety disorders (Beck, Laude, & Bohnert, 1974) and often appear to embody clients' distorted beliefs about the dangerousness of feared situations. In comparison with verbal propositional representations, images are thought to have a special link with emotion. Vrana, Cuthbert, and Lang (1986) reported that imagining fearful stimuli elicited more physiological activity than when the same information was thought about in verbal form, although this comparison was not balanced for order of presentation. More recently, Holmes and Mathews (2005) required volunteers to either imagine unpleasant events or listen to the same descriptions while thinking about their verbal meaning. Participants in the imagery condition reported more anxiety and rated new descriptions as more emotional than those in the verbal condition.
Mental images are cognitive representations of perceptual information that are not the product of current external sensory input. Images can comprise any or all sensory modalities (e.g., visual, sound, tactile; Horowitz, 1970). Hackmann (1999) noted that, within the clinical context, images most typically encompass a range of sensory qualities. The visual modality is the most common imagery modality reported, albeit not exclusively in a range of psychological problems including agoraphobia (Day, Holmes, & Hackmann, 2004), body dysmorphic disorder (Osman, Cooper, Hackmann, & Veale, 2004) and cravings (May, Andrade, Panabokke, & Kavanagh, 2004).
