Measuring sexual interests with pupillary responses

During the visual processing of sexual content, pupillary responses have been positively associated with observers' sexual orientation. The question of whether this measure also reflects age-specific sexual preferences, however, is rarely considered. This is remarkable given the potential applied value of pupillary responses for directly measuring unhealthy and inappropriate sexual desires in clinical and forensic settings. The experiments in this thesis addressed this question with a series of tasks whereby observers' viewed images of adults and children while their eye movements and pupil responses were recorded. These results were then compared with sexual appeal ratings for these images and self-report questionnaires relating to sexual interests and experiences. The main findings indicate that pupil dilation is a measure of sexual orientation that is particularly robust and consistent for male participants (Chapters 2 to 4). Furthermore, these experiments provide initial evidence that pupil dilation could also be used as an age-specific measure of sexual interest in males and females (Chapters 2 and 3). Additionally, this thesis explored the influence of low-level stimulus artefacts within the scenes on pupillary patterns (Chapter 2). Findings provide further evidence that the pupillary responses obtained in these experiments are driven by the person content in the scenes. These findings are discussed in relation to existing research on eye-tracking and other current measurements of sexual interest.