Metacognition (typically defined as "cognition about cognition") allows us to monitor our own thoughts and feelings. So broadly understood, metacognition can be applied to a wide range of mental domains. For example, we use metacognition to monitor our perception of events generated in the external world and to seek further evidence if we are unsure of what we have perceived. We can also accurately report mental states generated internally, like the contents of our thoughts, the focus of our attention or our intentions to move.

Despite the wide and disparate range of domains on which metacognition operates, most experiments have focussed on perception in general, and vision in particular. This is most likely simply out of convenience: It is relatively easy to present carefully controlled visual stimuli to participants, in order to measure metacognitive ability free of other confounds. Studying metacognition of other perceptual domains and, further, of internally-generated processes is much harder. However, it is yet unclear whether, and to what extent, results from visual metacognition can be generalized to other domains.  

Affiliation: Humboldt Universität zu Berlin