Previous research on the relationship between emotion and attention has focused primarily on attention to emotionally valenced stimuli; trait anxiety and attentional biases for threat; or the relationship between emotion and attention in clinical contexts. Few studies have investigated the effect of emotion on attentional processing irrespective of the valence of the stimuli that is being attended. However, such studies are important as they shed light on issues central to emotions theory such as whether the experience of discrete emotions is associated with distinct patterns of attentional processing. In this thesis six experiments and one correlational study are described. The experimental studies investigate whether the experience of discrete emotions - specifically amusement, happiness, sadness and fear - influence attentional processing in comparison to a neutral condition. Film clips, emotional images and music were used to elicit a target emotional state. A modified version of the Attention Network Test (ANT) was used to assess three forms of attention – phasic alerting, covert exogenous orienting and executive attention. The correlational study required participants to complete a set of emotion-related questionnaires including the Basic Emotion Scale (BES) and to perform the ANT. The results suggest that: i) fear reduces executive attention costs, ii) sadness reduces intrinsic alerting, but does not influence alerting, orienting or executive attention, iii) amusement and happiness do not differentially influence alerting, orienting or executive attention, iv) individual differences in the tendency to experience high arousal negative emotions are associated with phasic alerting, i.e. faster mobilisation of attentional resources in response to an impending stimulus and v) exogenous orienting of attention may be impervious to the influence of emotion, at least in context of neutrally valenced stimuli. Results relating to anxiety, emotion regulation and attention network performance are also discussed. Taken together these findings provide only limited support for the broaden-and-build theory (Fredrickson, 1998) of positive emotions. Amusement and happiness did not result in broadening (as assessed by executive attention costs) in the present studies. An attentional narrowing effect was found for fear but not for sadness. It is proposed that fear, but not sadness, facilitates inhibition and reduces executive attention costs, indicative of more focused attention. The results here also suggest a relationship between negative emotions characterised by high arousal and phasic alerting – an aspect of attention which has received little coverage in emotions research to date. Implications relating to the use of the ANT as a measure of attentional performance, and the challenges associated with manipulating emotion in a lab setting are discussed.