Our pupil size changes not only in respect to light level but also with the emotional content of a stimulus and our arousal to it (e.g., Hess, 1965; Bradley et al., 2008). Our aim is to develop this paradigm to provide us with an instrument that can measure a person's automatic and unconscious processing of emotional stimuli. Such an instrument is really needed for work with people with diagnosed Personality Disorders (PD) where problems with the processing of emotions is central to their symptoms and distress (hypo-responsivity in psychopathy and hyper-responsivity in Borderline PD). No such studies exist as yet.
The work will develop the basic paradigm (Bradley et al, 2008) to eliminate luminance and other stimulus artefacts, to consider the effects of basic stimulus parameters (e.g., presentation time), to show test-retest reliability and its relationship to normal personality traits. We will then gather data from a small sample of patients with diagnosed PDs. These data will be used to demonstrate the feasibility of the study and as pilot data for an application for a large-scale grant to study emotional processing in patients with a range of PDs in both community and secure units using our existing research collaborators.