In the past few years, there has been an explosion of eye movement research in cognitive science and neuroscience. This has been due to the availability of 'off the shelf' eye trackers, along with software to allow the easy acquisition and analysis of eye movement data. Accompanying this has been a realisation that eye movement data can be informative about many different aspects of perceptual and cognitive processing. Eye movements have been used to examine the visual and cognitive processes underpinning a much broader range of human activities, including, language production, dialogue, human computer interaction, driving behaviour, sporting performance, and emotional states. Finally, in the past thirty years, there have been real advances...