| Summary: | This thesis investigates the allocation of visual processing resources to stimuli perceived as being threatening by individuals with an increased fear of spiders. The literature in the broad field of cognitive psychopathology suggests that, throughout a number of subtypes of anxiety, there is a visual processing bias that causes anxious individuals to rapidly notice threatening objects in their environment. It is further suggested that individuals with low or normal levels of anxiety do not display the same pattern of attentional allocation. The thesis reviews the range of theories and the experimental paradigms that have informed them and suggests that in the majority of cases methodological limitations lead to different interpretations of the results. Additionally, alternative interpretations of the findings, namely that of the delayed disengagement hypothesis, which suggests that anxious individuals are not faster at detecting images than low anxious control participants, but rather they display a bias where they are unable to rapidly disengage their attention from threatening stimuli when they have been noticed, are explored. The thesis then investigates the use of a method from the perception and attention literature, called inattentional blindness. It is proposed that the inattentional blindness experiment is able to overcome the methodological difficulties associated with current methods in cognitive psychopathology. A series of experiments are detailed investigating the allocation of attention to neutral and spider images in individuals with increased fear of spiders. The first series of experiments suggests that, relative to control participants with low levels of spider fear, individuals with an increased fear of spiders do rapidly allocate attention to spiders appearing in their left visual field. The thesis also examines whether heightened anxiety causes a general hypervigilance of the attentional system. However, the results do not confirm this prediction. Two additional experiments were conducted. Firstly, one investigating whether individuals with a fear of spiders display difficulties disengaging their attention from spider stimuli. The results from this experiment do not confirm the delayed disengagement hypothesis. Secondly, an experiment using the dynamic inattentional blindness paradigm was developed to investigate attentional allocation to spider stimuli in individuals with high and low spider fear. The results provide partial support for the hypothesis that the high, but not the low, fear group, notice moving spiders when they are presented against expectation. The implications of these results are discussed.
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