Ground control to Major Tom: Experimental manipulation of anxiety-related interpretation bias by means of the “space odyssey” paradigm and effects on avoidance tendencies in children

Abstract

The “space odyssey” paradigm refers to an experimental method that can be used to manipulate interpretation bias in youths. In this study, the “space odyssey” paradigm was employed to induce either a negative or a positive interpretation bias in a sample of 120 non-clinical children aged 9–13 years. The results indicated that children's interpretation bias and avoidance tendencies scores were successfully manipulated during the experiment. That is, children in the negative training group showed an increase in negative interpretation bias and avoidance tendencies, whereas children in the positive training group exhibited a decrease in interpretation bias and avoidance tendencies, although it should be admitted that these effects in general were rather weak. Further, no support was found for the idea that high-anxious children were more affected by the experimental manipulation than low-anxious children.

Introduction

During the past decades, various theorists have noted that cognition plays an important role in the pathogenesis of anxiety problems (e.g., Beck, Emery, & Greenberg, 1985; Williams, Watts, MacLeod, & Mathews, 1997). Kendall (1985) has adopted this idea in his cognitive theory of childhood anxiety, which proposes that anxious youths have overactive schemas involving the themes of vulnerability and danger. When confronted with potential threat, novelty, or ambiguity, these maladaptive schemas strongly guide the processing of information and chronically focus resources on threat-relevant information. This can be nicely illustrated by means of a cognitive phenomenon that is labeled as ‘interpretation bias’, which refers to the tendency to attach a threatening meaning to ambiguous stimuli and situations, and might explain why anxious individuals so readily evaluate fairly benign situations as dangerous.

Interpretation bias has been examined in various studies with children and adolescents. In an investigation of Barrett, Rapee, Dadds, and Ryan (1996), anxiety disordered youths, youths with oppositional defiant disorder, and normal controls (all aged between 7 and 14 years) were presented with brief vignettes of ambiguous situations and asked about what was happening in each situation. Then, youths were given two possible neutral outcomes and two possible threatening outcomes and asked which outcome was most likely to occur. Results showed that both anxious and oppositional youths more frequently interpreted ambiguous situations as threatening than normal controls. Interestingly, anxious youths more often chose avoidant outcomes, whereas oppositional youths more frequently chose aggressive outcomes. A different experimental approach was employed by Hadwin, Frost, French, and Richards (1997) who measured general anxiety levels in 7- to 9-year-old children, and then confronted them with ambiguous homophones that either had a neutral or a threatening interpretation (e.g., dye versus die). The results showed that anxiety levels were positively associated with threatening interpretations of homophones. Thus, higher anxiety levels were accompanied by a higher frequency of threatening interpretations. Altogether, these and other studies using the vignette paradigm (e.g., Bögels & Zigterman, 2000; Dineen & Hadwin, 2004; Muris, Rapee, Meesters, Schouten, & Geers, 2003; Waters, Craske, Bergman, & Treanor, 2008) or the homophone task (Taghavi, Moradi, Neshat-Doost, Yule, & Dalgleish, 2000) have shown that interpretation bias is a cognitive distortion that occurs in high-anxious and anxiety disordered youths.

Although there is supportive evidence indicating that cognitive distortions such as interpretation bias occur in anxious children and adolescents, one of the key questions remains how these distortions develop (Muris & Field, 2008; Vasey & MacLeod, 2001). While it is generally assumed that inherited temperament or personality characteristics such as neuroticism for a large part determine this type of cognitive distortion (e.g., Eysenck, 1992), there is evidence suggesting that environmental influences are also involved. For example, Creswell, O’Connor, and Brewin (2006) employed an ambiguous vignette task to measure interpretation bias in a mixed sample of clinically anxious and non-clinical children (aged 7–15 years) and their mothers. The results showed that children's and mothers’ interpretation bias scores were positively correlated, suggesting that “children's information processing style may result from internalization of parental perception of threat” (p. 1379; see also Creswell, Schniering, &, Rapee, 2005). In the aforementioned study of Barrett et al. (1996), family influences on children's interpretation bias were investigated in more detail. After youths had given their initial response to the ambiguous vignettes, parents were asked to discuss the situations with their offspring, after which children provided their final response to the vignettes. The results indicated that the family discussions enhanced the cognitive bias in clinically referred youths, with anxious children displaying an increase in avoidant responses (see for a similar finding: Chorpita, Albano, & Barlow, 1996) and aggressive children showing an increase in aggressive reactions.

Although these findings suggest that interpretation bias in children is passed on from parents to their children, it remains unclear what mechanism is responsible for the transfer of this cognitive bias. One possibility is that biased interpretation is installed by anxious parents who, due to their own interpretation bias, frequently provide negative feedback about ambiguous stimuli and situations to their children. Interestingly, Mathews and colleagues (Mathews & Mackintosh, 2000; Mathews & MacLeod, 2002) have described an experimental paradigm to demonstrate that interpretation bias can be learned by training. Participants were exposed to verbal descriptions of ambiguous events and positive or negative resolutions to these events were either provided in the text or were actively generated by participants through a fragment completion task. In this way, the researchers successfully installed an interpretation bias that persisted beyond the training trials, thereby demonstrating that this type of cognitive bias can be the result of negativistic learning experiences.

Most studies on the experimental training of interpretation bias have been conducted with adults (Grey & Mathews, 2000; Mathews & Mackintosh, 2000; Mathews & MacLeod, 2002; Salemink et al., 2007a, Salemink et al., 2007b; Wilson, MacLeod, Mathews, & Rutherford, 2006; Yiend, Mackintosh, & Mathews, 2005). So far, there is only one investigation that explored this issue in a child population. In that study, Muris, Huijding, Mayer, and Hameetman (2008) describe the development of the “space odyssey” paradigm, which makes it possible to manipulate children's interpretation bias in an ethically acceptable way. This paradigm essentially is a computer game of an imaginary journey to an unknown planet during which children get acquainted with the unknown living conditions on the new planet. They are presented with brief scenarios describing unknown stimuli and situations. For each scenario, children have to choose between a negative (i.e., mildly threatening) or a positive outcome. Children continuously receive feedback on the correctness of their choices. In one half of the children the choice of negative outcomes is reinforced (i.e., negative training group), whereas in the other half the choice of positive outcomes is reinforced (i.e., positive training group). Following the training, an interpretation bias task is administered: children are confronted with ambiguous scenarios describing everyday situations that could also occur on earth (e.g., going to school, encountering unfamiliar people). The main task of the children is to rate the level of threat associated with each of these situations. A first test of the paradigm in a sample of 70 non-clinical children aged 8–12 years (Muris et al., 2008) showed that the training procedure was successful. Children in the negative training condition quickly learned to choose negative outcomes for the unknown scenes, whereas children in the positive training condition rapidly learned to select positive outcomes. Most importantly, children's subsequent interpretation bias scores were affected by the experimental training procedure. That is, children in the negative training condition displayed higher levels of threatening interpretations than children in the positive training condition. Moreover, an additional analysis indicated that this pattern of results was particularly pronounced for children who already exhibited high levels of anxiety symptoms. The latter finding is interesting because it suggests that more vulnerable (i.e., already more anxious) children were especially sensitive to the experimental manipulation.

While these initial results on the experimental induction of interpretation bias in children are promising, it is clear that a number of important issues need to be resolved. To begin with, the Muris et al. (2008) study did not include a baseline assessment, and so it was not possible to examine the change in interpretation bias as a result of the experimental manipulation. Obviously, a pre- to post-test design is necessary to definitely demonstrate that a negative training indeed enhances children's interpretation bias scores. Such a design may also reveal whether a positive training is able to reduce this type of cognitive bias. Further, Muris et al. (2008) only investigated whether the experimental procedure had an effect on children's cognitive bias. Thus, it remains to be seen whether this experimental paradigm also produces an effect on children's anxiety levels. Although previous research has shown that this seems to be the case in adults (e.g., Mathews & Mackintosh, 2000; Salemink et al., 2007a, Salemink et al., 2007b, Wilson et al., 2006), it remains to be seen whether such effects can also be demonstrated in child populations. With these issues in mind, the present study was conducted. More precisely, the “space odyssey” paradigm was employed to induce either a negative or a positive interpretation bias in non-clinical children. The use of a pre- to post-test design enabled us to examine whether children in the negative training group would show an increase of interpretation bias scores as a result of the experimental procedure, whereas children in the positive training group would display a decrease of this cognitive bias. Further, a self-report measure of avoidance tendencies was added to the study as a proxy index of children's anxiety levels in relation to the “space odyssey” experience, so that it became possible to investigate whether the experimental manipulation not only had an impact on cognition but also influenced children's emotion. Finally, we explored whether the training procedure has more impact on children who already exhibit high levels of anxiety disorders symptoms. On the one hand, it was inquired whether these high-anxious children are more susceptible to a negative training and as such develop a stronger negative interpretation bias and display higher levels of avoidance tendencies as compared to low-anxious youths (see Muris et al., 2008). On the other hand, it was tested whether precisely high-anxious children profit more from a positive training, which would suggest that the manipulation of interpretation bias may have therapeutic benefits.