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This thesis examined the association between parental anxiety and child-related information processing biases. Paper 1 describes a review of the extant literature concerning information processing biases in anxious parents. Although the published research in this area was found to be limited and characterised by contradictory findings, both parental threat interpretation biases and biases in parental estimations, evaluations and expectancies were found to be associated with parental anxiety. Furthermore, evidence that these biases influence the processing of child-related information as well as self-referent information was identified. In addition to these findings, the review highlighted a number of weaknesses within the literature, specifically in relation to study design, methods of measurement and sample characteristics. In order to address the limitations of existing measures of child-related parental threat interpretation, a more methodologically rigorous approach for assessing the interpretation of ambiguity was adapted for use with parents. As reported in Paper 2, fifty-four community-based parents with a child aged between two and eleven years participated in an experiment designed to measure whether state anxious parents interpret ambiguous situations involving their child as threatening. Results indicated no difference in patterns of interpretation between state anxious and non-state anxious parents. Methodological weaknesses associated with the study design prevented definitive conclusions regarding the existence of a child-related threat interpretation bias in anxious parents from being made. In Paper 3, the approaches used within the current thesis are evaluated in terms of their strengths and weaknesses. Clinical implications of the findings are discussed and ideas for further research are outlined.

The portfolio has three parts. Part one is a systematic literature review, in which the experimental empirical literature relating to memory biases in Generalised Anxiety Disorder (GAD) is reviewed. Information processing models have suggested that anxious individuals should be characterised by a memory bias towards threat. However, other models have proposed that memory biases may not be evident, as anxious individuals avoid the elaboration of threatening material. Ascertaining whether or not a memory bias exists is fundamental to the development of theories and associated treatment of GAD and worry, its hallmark feature. To answer this question, a systematic and comprehensive search of the literature was undertaken. The results of the review highlight that there is a paucity of studies in this area, which are conflicting in their findings. The majority of the studies examined memory biases in GAD utilising explicit and implicit memory paradigms and only one previous study has examined autobiographical memory biases in GAD. A series of conceptual and methodological issues are outlined and areas for future research are discussed.Part two, the empirical paper was derived from the recommendations described in the systematic literature review. This study explores Autobiographical Memory Biases in Worry. Sixty participants with varying levels of worry completed an autobiographical memory task in response to threatening worrisome thoughts which were rated by participants for personal relevance. The findings suggested that individuals high in pathological worry do not recall more threatening autobiographical memories when presented with highly personally relevant concerns, however when prompted with a concern that is not relevant evidence of a memory bias is suggested. It was also found that depression may be a key variable in whether a general memory bias towards threat is detected in worry. No significant results were found with regards to the relationship between the level of worry and retrieval latency of memories or the coping strategies recalled. However, there are a number of methodological and conceptual issues that should be taken into account and may explain the non-significant findings. Areas for further research are highlighted.Part three comprises the appendices.

When an individual perceives a situation or stimulus as anxiety-provoking they may react behaviourally; often actions are carried out that make it possible for the individual to cope with the anxiety. Thus, the individual comes to associate the elicited behaviour with a decrease in anxiety. Potentially, when such behaviours are carried out, conditioned inhibitors, or safety signals, are generated. On theoretical grounds, these are expected to help maintain and secondarily reinforce the behaviour. The current thesis examined both conditioned inhibition and the learning of stimulus–response associations in both a healthy sample and a clinical sample of participants with anxiety disorder and/or problems with substance abuse. Two novel tasks were developed and one previously used task was used to examine conditioned inhibition, Negative Images CI Task: Retardation Test, Negative Images CI Task: Summation Test and ‘Mission to Mars’ CI Task: Summation test respectively. Four response inhibition tasks were developed to examine any accuracy or reaction time differences to neutral and emotional stimuli: Emotional Stroop Task, Go/No-Go Words Task, Go/No-Go OCD Colour Images Task, Go/No-Go Black and White Images Task. Performance on all of the tasks was correlated with individual differences in anxiety as measured by questionnaires: HADS, MOCI, BIS/BAS and the EPQR-S. The results from the healthy sample tested showed clear evidence of discrimination learning, as well as conditioned inhibition as measured by both retardation and summation tests. There were also response inhibition differences on the Emotional Stroop, a classic Stroop effect, less accurate and slower for colour incongruent words compared to other word-types, and more accurate and quicker responses to negative and OCD related words. There were no response inhibition differences on any of the Go/No-Go tasks. Further to this, in general, individual differences in anxiety as measured by the HADS, MOCI, BIS/BAS and EPQR-S were related to performance on the tasks. The hypothesis was that individuals formally diagnosed with an anxiety disorder would show better conditioned inhibition and response inhibition deficits. Recruitment for the clinical sample was unexpectedly difficult and therefore the sample size provides only preliminary data. The results from the clinical sample tested showed no difference in performance on any of the tasks; thus a formal clinical diagnosis of either an anxiety disorder or substance abuse disorder did not measurably impact on performance. However, overall the clinical group did not show discrimination learning or conditioned inhibition. On the Emotional Stroop Task the clinical sample showed a classic Stroop effect for accuracy and was also more accurate for negative words but there was no difference in latencies. There were no differences in performance on any of the Go/No-Go tasks. Across all of the tasks the clinical sample demonstrated a relationship between task stimuli and individual differences as measured by the HADS, MOCI, BIS/BAS and EPQR-S related to performance. The results from the current tasks demonstrated that inhibitory processes are influenced or affected by individual differences in anxiety in a healthy sample; in particular certain measures either positively or negatively influence performance. In order for this to be fully conclusive all of the tasks carried out need to be tested in a larger clinical sample. The results have implications for psychological treatments, for example, cognitive behavioural therapy (CBT). CBT is based on associative learning principles, if safety signals were identified in the maintenance of the anxiety these could be incorporated into therapy and aid the breakdown of negative associations formed.

Social phobia is a highly prevalent and debilitating anxiety disorder that can significantly impact quality of life and produce extreme distress in social situations. Cognitive models of social phobia suggest that information-processing biases are involved in the maintenance of social anxiety. Treatment typically involves a course of Cognitive Behavioural Therapy (CBT). Recent advancements in the understanding of the mechanisms underlying social anxiety have led to specific adjunctive treatments that target processing biases. The current literature review explores the efficacy of training programs designed to modify interpretative biases. Training programs typically involve repeated exposure to positive resolutions of ambiguous lexical social stimuli. Results suggest that current techniques are able to modify interpretative biases in non-anxious, socially anxious and clinical samples of social phobia. Multi-session programs have also been shown to reduce trait anxiety and social anxiety symptoms. Evidence for the generalisability of training to subsequent socially stressful situations remains mixed and requires further research. In the present study, the validity of a novel cognitive bias modification of interpretation (CBM-I) technique using ambiguous facial stimuli was examined in an unselected sample of 65 undergraduate students. Participants were randomly allocated to receive CBM-I-threat (n=31) or CBM-I-non-threat (n=34) training. The number of angry responses in a forced alternative (angry, neutral) choice was compared at pre and post assessment to determine the efficacy of training. Participants completed a subsequent social stressor task (impromptu speech). Measures of state anxiety, physiological measures of arousal, and judgements of speech performance were taken to examine the effects of training on emotional vulnerability. Results showed that the training program successfully induced a bias towards threat in the CBM-I-threat trained group. There was also some evidence that it was able to reduce the number of threat interpretations in CBM-I-non-threat trained individuals, however this was only when facial expressions were ambiguous. Early results suggest CBM-I training may also effect anticipated and retrospective negative evaluations of social performance.

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This thesis aimed to investigate the genetic basis of anxiety in mice. The first half describes searches for genetic variation beneath quantitative trait loci (QTLs) and computationally pulls together data from several sources in order to assess how likely each variant is to be responsible for the QTLs. The second half describes the results of the behavioural phenotyping of three knockout mouse models. Examination of the sequence data beneath anxiety-related QTLs mapped from quasi-outbred mice identified 326 variants across eight inbred mouse strains in the coding and promoter regions beneath a prominent QTL for startle behaviour on murine chromosome 15. Variants in the genes Muc19, Gxylt1 and Kif21a were pinpointed as being most likely to contribute towards the phenotypic variation of that QTL. 12 structural variants (SVs) were also identified across the same strains as being potentially causal for at least one QTL when the search was extended to the whole genome. Testing the association between SV genotype and phenotype in an outbred murine population implied that SVs in the genes Fam110c, Fam117a and Gm6320 had similar phenotypic associations across different populations of mice, although the associations in the outbred mice did not achieve statistical significance. From the work with the three knockout mouse models, it was concluded that two of the genes, Eps15 and Car2, do affect anxiety in male animals, with Eps15 deficiency reducing anxiety and Car2 deficiency increasing it. The results for the Dstn mouse model were inconclusive. This model may need to be reengineered onto a less anxious background for future testing. In conclusion, this thesis identified a number of genes and genetic variants, some of which do seem to affect murine anxiety levels. Improved understanding of anxiety in mice will hopefully lead to a better understanding of the causes and treatment of anxiety disorders in humans.

Mindfulness derives from meditative traditions and is a form of mental training that is increasingly incorporated into Western treatment approaches for common mental health problems. This thesis addresses the prophylactic effects of mindfulness practice and the implications for the treatment of anxiety. The first paper considers the role of attention as a predominant mechanism of mindfulness. The paper reviews the evidence for the effects of mindfulness on attentional subsets and suggests that mindfulness may in part exert its benefits by ameliorating maladaptive attentional processes that have been implicated in the aetiology of anxiety. The empirical paper reports the results of a randomised controlled trial that directly compared the prophylactic and differential effects of two mindfulness practices on pharmacologically-induced state anxiety and negative affect through inhalation of 7.5% carbon dioxide (CO2). 60 participants engaged in 10 minutes of focused mindfulness, open mindfulness or relaxation prior to a 20-minute inhalation of 7.5% CO2 or air. Consistent with the evidence-base, this study found that mindfulness reduced self-reported state anxiety and negative affect significantly more so than a period of relaxation. In the context of non-significant reductions in autonomic measures of arousal, these findings support that mindfulness exerts its benefits through specific rather than non-specific effects. The results are consistent with contemporary conceptualisations of mindfulness mechanisms that highlight the key role of attention and suggest that clinical effects are exerted through top-down control mechanisms that support emotion regulation.