Publications arising from this thesis include: Chapter 4: Williams, S. E. & Cumming, J. (2011). Measuring athlete imagery ability: the Sport Imagery Ability Questionnaire. Journal of Sport & Exercise Psychology, 33, 416-440. http://eprints.bham.ac.uk/975/ Chapter 6: Williams, S. E., Cumming, J., & Balanos, G. M (2010). The use of imagery to manipulate challenge and threat appraisal states in athletes. Journal of Sport & Exercise Psychology, 32, 339-358 http://eprints.bham.ac.uk/362/