In a nutshell
Steve and Chris Frith define and discuss metacognition in a podcast for the Royal Society
Read Steve's article in Scientific American MIND on insight and metacognition
Our book on metacognitive neuroscience
A bit more detail
The core question that drives most of what we do in the lab is: how does the human brain understand itself? Studying metacognition provides a useful framework for answering this question. Just as the study of the visual system relies on building and testing models of how people perceive the outside world, we use similar tools (psychophysics, computational modelling, neuroimaging) to understand how people self-reflect and and monitor their cognition and behaviour.
Core questions we are interested in include: which neural substrates support metacognition? Does metacognition rely on common or distinct mechanisms across different domains, such as perception and memory? How do "local" fluctuations in metacognitive estimates relate to "global" variables such as self-esteem and anxiety? Is metacognition disrupted in mental health, and can we develop techniques and approaches to restore or improve metacognition? What's the use of self-reflection, and how does it aid self-control?